tree design guide may 06

8/12/2019 Tree Design Guide May 06

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N e w c a s t l e C i t y C o u n c i l

Highway TreeDesign Guide


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STANDARD DETAILS & SPECIFICATIONS

for

HIGHWAY TREE PLANTING

Formally Adopted by the Executive of

Newcastle City Council

on 17 May 2006


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STANDARD DETAILS & SPECIFICATIONS

for

HIGHWAY TREE PLANTING

This document aims to provide a set of guidelines and details for tree planting within or

adjacent to the public highway and for the various situations and conditions that are likely

to be encountered. The document is divided into five sections:

1 Introduction, background and supporting documentation for the Specifications

2 The planting operation a work sequence

3 Specifications

4 Recommended trees lists of species suitable for Newcastle upon Tyne

5 Detail drawings

1.00 INTRODUCTION

1.1 THE CASE FOR HIGHWAY TREES

1.1.1 There is a compelling case for trees in the centre of our towns and cities, alongside

main highways, in suburban streets and on development sites. In 1993, the UKStrategy for Sustainable Development stated Trees in towns are an important

resource which enhances the quality of our urban environment. (1)

The aesthetic argument is often the strongest but often the most difficult to prove.

Expressed most simply, it could be said that trees improve our quality of life.

More obvious benefits include:-

- noise reduction

- control of airborne pollutants

- improvements to energy efficiency

- benefits for wildlife.

1.1.2 The City of Newcastle upon Tyne has formally adopted a tree strategy: Trees

Newcastle, A Tree Strategy for Newcastle upon Tyne. (2) This document contains

policy and guidance on the care and maintenance of the Citys tree stock and for

increasing the number of trees throughout the City to improve amenity, biodiversity

and to make Newcastle a greener and more attractive city. There is also a five year

Action Plan to achieve these objectives. Objective 7 states that the City


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will.develop a programme to plant more street trees.increase the number of

street trees..increase the number of trees in the City centre.

1.1.3 It is quite easy to demonstrate that trees have a powerful impact on peoples

perceptions of the visual quality of streets and urban spaces. Not only do people

feel better in a tree-lined environment (whether or not the individual recognises this)but they are prepared to pay to live in one. Studies in the United States have

demonstrated property values of up to 20% higher in a tree-lined street than

identical properties in a street without trees.(3) (There is no indication of how this

relates directly to the UK housing market).

Conversely, deformation of pavings, problems caused by fallen leaves and

branches, damage to adjacent services and adjacent buildings, and safety issues

have all been cited at one time or another as a reason not to plant trees. Withcorrect detailing of the planting area, careful choice of species and good

management most of the problems can be overcome, hence the reason for this

document.

1.1.4 Large, mature trees are the most valuable. Not only do they provide a much

needed sense of scale for people in the built environment but a mature Beech for

example can produce enough oxygen for ten people every year and fix over 2 kg of

carbon dioxide an hour. (4)

1.1.5 The survival of newly planted trees cannot be left to chance. Estimates for the

survival of new trees in urban areas start as low as 50%, with only 10% of dead

trees caused by vandalism. (5)

This need not be the case. Trees are highly adaptable to hostile environments and

with the correct specifications, choice of species and variety and attention to detail

at all stages of the project, there is no reason why survival and subsequent growth

should not be comparable to a non-urban situation. (Research indicates that mean

shoot extension of urban trees is only 58% of that in similar trees in a nursery or

arboretum environment). (6)

1.2 SPECIFICATION GUIDELINES AND SUPPORTING INFORMATION

1.2.1 The following sections propose methods for successful tree planting in situations

that are commonly encountered in Newcastles highway areas and provides

background information to the specifications. They include both paved and unpaved

sites and cover a range of tree sizes.


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Where specific guidelines are given then reference should be made to the relevant

specification and drawn detail as indicated. .

The guidelines are set out under the following headings

1.3 The Site Page 4

1.4 Planting Pits Page 5

1.5 Soil Page 7

1.6 Root Barriers Page 8

1.7 Drainage Page 9

1.8 Tree Support Page 9

1.9 Irrigation & Aeration Page 11

1.10 Tree Selection Page 12

1.11 Tree Guards Page 15

1.12 Tree Grilles & Pit Surfaces Page 15

1.13 The Planting Procedure Page 16

1.14 Establishment & Maintenance (years 1 5 inclusive) Page 17

1.3 THE SITE

CONSTRAINTS

1.3.1 When an area is identified for tree planting there are a number of check proceduresthat must be undertaken before a detailed design can be agreed -

Underground services - contact all Public Utility Companies to establish the

exact location of pipes, cables, etc.. Tree planting shall not take place directly

over live services unless they are in excess of 3m deep, or in the case of mains

water and drains, 5m deep.

Aerial services trees must not be planted where, as they increase in size, they

may foul overhead cables, block windows or interfere with street lighting orCCTV cameras.

Carry out a visual survey for constraints such as nearby street lighting,

overhead lines, road signs, and nearby junctions. The presence of any of these

may not prevent tree planting but it is advisable to contact City Engineering

Services, City of Newcastle upon Tyne, for advice. They will also be able to

advise on sight lines at the approach to any junctions or turnings.

Existing trees will affect the growth of the new trees due to shading and

competition and will affect the proposed planting location. New trees will not

thrive or grow evenly under the canopy of existing trees.


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1. 3.2 Risk management tree planting in highway situations, as in any other location,

has a number of attached risks that must be taken into account during the planning

and implementation of the scheme.

Long term risks from established trees include

damage to persons or property from falling trees or debris from trees such as

branches, leaves and fruit.

damage caused by growing roots to surrounding pavings creating a hazard for

pedestrians and vehicles.

damage caused by roots to nearby property including building foundations,

drainage and other service lines.

obstructing sightlines, street lighting and road signs for drivers of vehiclestherefore creating a potential hazard to road users.

Risks to be considered during the planting operations

access to verges etc. from active highway, possibly with traffic management

implications

excavation of tree pits and manoeuvring of soil, trees, paving materials adjacent

to active highway and pedestrian areas.dangers to site operatives from vehicles on the adjacent highways.

1.4 THE PLANTING PIT

1.4.1 Existing Ground -

excavate one planting pit to act as a trial pit that will enable the following to be

established:

- quality of topsoil- possible drainage problems

- the presence of underground services

1.4.2 Quality of topsoil as defined in BS 3882:1994. It is possible to assess the quality

of soil by using a simple finger and thumb test as outlined in the BS but essentially

a light, sandy and open texture is required. Where the excavated topsoil from the

planting pit, and the surrounding soil, is of a suitable quality then it is of little benefit

to add any other medium during the planting operation with the exception of a slow

release fertiliser (such as Bonemeal or Scotts Enmag ), applied at the time of

planting and at manufacturers recommended rates.


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If the soil has a poor texture then it is possible to improve this with conditioners

such as peat-free compost made from recycled organic materials as available from

Parks and Countryside Training (PACT) within the area of the planting pit and

applied at an approximate quantity of 3 parts soil to one part compost. It is not

possible to make long term improvements to, say, pH or nutrient content, to such anextent as to benefit the tree for more than its initial establishment period.

It is also important to recognise that digging a pit in clay soils and backfilling with a

lighter, free draining planting medium, is likely to result in the creation of a sump

into which water from the surrounding ground will flow. In these circumstances, a

drainage layer at the base of the planting pit should be provided or connection to an

established drainage system via pipework. (see section 1.7)

1.4.3 New Ground -

In new ground, or in areas of major excavation, it is possible to create conditions

that will give new trees the best possible start and minimise future disruption to the

surrounding area. This will include:

- adequate soil volumes

- good quality topsoil

- protection to surrounding pavings and adjacent services

- drainage provision if necessary

In urban areas, where little or no existing soil is within reach of growing roots, the

size of the planting pit and the quality of soil are the two most important factors that

will have a bearing on the future growth of the trees.

1.4.4 Pit Size - Soil Volumes

The volume of soil required to support a mature tree depends on type and ultimate

size of the tree, water availability and ground water storage, particularly during drier

seasons. While formula are available to calculate the volume of soil required,

20 cu m appears to be required to maintain reasonable growth in a paved situation.

(7)

When planting into existing areas this volume may be difficult to achieve but it must

be recognised that trees planted in a lower volume of soil may not reach their

ultimate mature size and maintain good leaf growth/ shoot extension, unless their

roots can extend beyond the pit into adjacent soil areas, e.g., grass verges,

gardens, etc. (8)


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Where possible a minimum soil volume of 5 cu m should be provided. The shape of

the soil area need not be regular and can be altered to suite site conditions.

Volume cannot be achieved by providing extra depth. The maximum useful depth of

topsoil for tree planting is 900mm.

It is acceptable for more than one tree to utilise the same soil. For example, a treepit 900 mm deep x 3 m wide x 8 m long containing 21 cu. m. of soil could support

two trees

planted at 6 m centres. A similar pit 16 m long containing 43 cu. m. would support

three trees, and so on. (see Diagram No. 6)

1.5 SOIL

1.5.1 Imported topsoil shall be of good quality, with a light texture, and conform toBS 3882 General Purpose Category. Unless the topsoil is from a reliable source

that previously supported good plant growth the following tests are required:

- pH - the soil pH should be between 5.5 7.8

- organic matter - which should be greater than 5%

- Nitrogen (N) - which should be greater 0.2%

- Phosphorous - which should be greater than 45 mg/kg

- Potassium - which should be greater than 240 mg/kg

- Magnesium - which should be greater than 80 mg/kg

More involved tests for phytotoxic elements (e.g. copper, nickel, zinc) and zootoxic

elements (e.g. arsenic, lead, mercury) need only be undertaken if there is any doubt

regarding the origin of the topsoil.

The tests must be undertaken by a recognised testing laboratory and presented to

the client prior to importing topsoil to the site.

1.5.2 The planting pit shall be backfilled only when the weather is dry and the soil in a

relatively dry condition. The pits should be backfilled in layers not exceeding

300 mm and lightly settled rather than compacted between each layer. As long as

the soil is not wet or heavy this is best achieved by light treading.

1.5.3 Areas of new ground - there are two alternatives for a planting medium - topsoil or

a manufactured soil (often referred to as Amsterdam or load bearing tree soil).

The main reason behind the development of 'load bearing tree soil was the search

for a planting medium that could be compacted sufficiently to withstand vehicles on


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a surface paving material while maintaining optimum conditions for root growth.

Compaction of typical topsoil sufficient to support vehicular paving will result in the

removal of the voids that water and oxygen would have filled.

Correctly installed, the tree soil is the ideal medium in this situation; it will not

deflect more than a few mm even when vehicles regularly use the surface. Whiletree soil is easy to specify and clean to use, it is expensive and, more importantly,

has a limited nutrient content. In the long term, supplementary feeding is likely to be

necessary to maintain tree growth. Where vehicle overrun is likely to be only

occasional then topsoil, with a reinforced paving surface, is to be preferred.

1.5.4 If the organic content is low or the structure of the soil can be demonstrated to be

poor (see 1.5.1 above) then a peat-free planting compost should be added at thesuppliers recommended rates. Alternatively, compost from a reliable source (see

note re PACT above) can be added at a rate of 1:3, by volume, ameliorant to

topsoil. In all cases the mixing must be carried out before adding the soil to the

excavated tree pit in order to obtain a homogenous mix. It is important to realise

that the gradual decomposition of organic material in the soil, resulting in a series of

small but linked voids, is one cause of settlement in surface paving adjacent to tree

pits. For this reason, load bearing tree soils are exceptionally low in organic

matter, not exceeding 5% by volume. (For compaction specification see 2.02)

1.6 ROOT BARRIERS

1.6.1 Where there is concern that adjacent services, such as gas and water pipes and

electricity cables, might be affected by growing root systems then an impenetrable

barrier should be installed which will prevent damage by future root growth.

1.6.2 A properly installed root barrier will, in effect, form a container and should be fitted

to the edges of the pit. Where there is danger of damage to services on just one

side, or any other reason why roots should be prevented from growing in one

direction such as building foundations, a strip barrier is preferable such as

Greenleaf Reroot 1000. The barrier must be installed from surface level to a

minimum of 1.0 m below surface level with joints overlapped by 300 mm. (see

Appendix 1)


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1.6.3 In a new build situation, within 8m of building foundations or adjacent to service

runs that are deeper than 1m the barrier must extend to a depth of 2m Greenleaf

Reroot 2000 or similar. (see Appendix 1)

1.6.4 Where excavation is limited to the area of the planting pit a pre-formed barrier (e.g.Greenleaf Root Directors) shall be installed to manufacturers instructions. The

barrier must be manufactured in such a way as to discourage the tree roots to spiral

around the inside but encourage them to grow in a downward direction.

In paving, the backfill surrounding the root director must be compacted

sufficiently to support the paved surface material and discourage roots that emerge

from the base of the director from reaching back up to the surface layers. (see

Diagram No. 4).

1.7 DRAINAGE

1.7.1 It is a prime requirement of any tree planting situation that planting pits do not hold

water and become waterlogged. In new construction the minimum requirement is a

layer of stone consisting of 200 mm deep of clean aggregate 50mm nominal size in

the base of the pit topped with a geotextile blanket, e.g Terram, to reduce

contamination of the drainage layer by fines. This will allow surplus water to drain

freely from the rooting zone.

The optimum solution is to connect this drainage layer of individual tree pits via

pipes to an existing surface water drainage system. In adopted highway this must

be done in full consultation with City Engineers (telephone number 0191 232 8520).

1.8 TREE SUPPORT STAKING AND GUYING

1.8.1 The purpose of staking and guying is to anchor the tree and stabilise the rootball

until new roots are established into the surrounding soil, it should not be seen as a

method of protecting from vandalism or physical damage. For this reason, support

is required until the roots, damaged during the lifting process, have made sufficient

new growth. In reasonable growing conditions this should be achieved within three

seasons after planting.

Above ground supports must be removed as soon as the tree is growing strongly,

an indication that the roots are re-established, thus allowing the main stem to bend

and sway in the wind which leads to increased thickening of the trunk. Trees where

the removal of the stakes has been delayed may exhibit a reduced girth, and


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therefore a weakened stem, in relation to the crown growth that can lead to the

stem snapping in a strong wind.

1.8.2 There are two main methods of supporting a newly planted tree, either above

ground by timber stakes, or underground with taut cables. Additionally there may because to use a hybrid of the above systems which uses tightly anchored cable to

support the trees above ground in the form of guys however this is to be

discouraged in public areas where the cables may present a health and safety

hazard. Above ground staking is unlikely to be successful with trees having a girth

greater than 30cm and a below ground system should be used.

1.8.3 Staking usually consists of one, two or three untreated softwood timber stakes, 75-100 mm diameter, driven at least 300 mm into the base of the pit.

Research indicates that the height at which the stake is attached to the tree has a

direct bearing on the subsequent growth and establishment of the tree. A tree will

establish anchor roots and increase stem girth more quickly if it is allowed to move

with the wind (while remaining firmly fixed at ground level).

This is best achieved by either using low stakes which are attached to the tree at

approximately 600 mm above ground level or by a higher triple stake system which

allows the tree a degree of movement between three ties.

A further advantage of low stakes is that snapping a young tree is much more

difficult when the lever point is low as opposed to a rigid point 1.5 m or so above

ground.

1.8.4 The tree should be fixed to the stake using proprietary rubber ties or a material such

as canvas hosing. Whatever product is used it is essential that it is firmly fixed and

that a spacing device prevents the tree chafing against the stake. (see Diagram

No.s 1E,2A,2B, 2C & 3A)

1.8.5 Support below ground is achieved by the use of cables, tensioned between

anchoring devices located at the base of the pit, across the rootball. It can only be

reliably used where the tree has a solid, firm rootball, which is supported by hessian

wrapping within an ungalvanised wire mesh basket. If underground staking is

proposed then it must be specified that the supplying nursery lifts and prepares the


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rootball using this method. The wire mesh basket should extend across the top of

the rootball thus providing protection to the roots from the taut cables.

It must be noted that, in nursery conditions, some varieties of trees never establish

a root structure that is dense enough to provide a solid rootball, e.g., some Sorbus

aria varieties. These trees cannot be supported by this method and double stakingwill be required. Again, the supplying nursery will provide advice.

1.8.6 Specialist proprietary ground anchor systems, such as Platipus, are available for

anchoring the cables and are useful where the ground below the base of the pit

makes driving a timber stake difficult.

1.8.7 In reasonable ground conditions, a triangular system of timber stakes 75 100 mmdiam., connected to each other using 5 mm diam. multi -strand galvanised wire

fixed with staples, and driven adjacent to the rootball so that the wires are drawn

taught across the top of the rootball. The mesh basket must not be cut or loosened,

it will rot away naturally without any danger of restricting root growth. The mesh

should also protect roots from the wire but if there is likelihood of damage the wire

can be sheathed in a length of plastic hose.

On no account must stakes be driven through a rootball as root damage is

inevitable. Timber stakes increase in size when in contact with ground water and,

as a result, hold tighter than metal stakes. For this reason timber stakes are to be

strongly preferred. (see Diagram No.s 1A,1B & 1D)

1.8.8 Alternative methods of anchoring the trees such as timber or concrete deadmen in

the base of the pits may be considered where it is not possible to drive stakes.

These must be placed at the time of pit excavation and fitted with all necessary wire

cables prior to back filling the pit and planting the tree. Tensioning of the wire is by

turnbuckle or ratchet systems. (see Diagram No. 1C)

1.9 IRRIGATION & AERATION

1.9.1 Research has shown that a proactive rather than a reactive approach to tree

irrigation during the first two or three seasons will have huge benefits to

establishment and longer-term growth. Applying water to newly planted trees that

are starting to show signs of drought stress may well keep them alive but will not


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stop stem die-back. This will result in poor establishment and possible long term

structural problems.

1.9.2 Surface irrigation is appropriate at planting time, particularly if this is towards the

end of the planting season when bud-burst may only be few weeks away, and withbareroot stock. A thorough soaking of the ground around the base of the tree will

ensure that soil is washed into voids around the fine roots of a bareroot tree or that

a rootball becomes thoroughly soaked.

A rootball composed of a different soil type to that in which it is planted may shrink

leading to voids between it and the sides of the pit which new roots are unable to

cross.

1.9.3 Later in the season, particularly during hot summer months, surface watering is

rarely efficient as the water is unlikely to penetrate the deeper root zone. It may

also result in roots remaining near the surface, which is to be avoided as much as

possible in a paved situation.

For future irrigation, the best method of ensuring correct water placement is by use

of a pipe leading from the surface to a point approximately 2/3 of the depth of the

rootball. From this point the pipe should encircle the rootball or, in the case of a

bare root tree be immediately adjacent the outer roots, and the water dispersed

through perforations in the pipe.

Proprietary systems are available e.g Greenleaf Root Rain system. It is important

to provide a removable cap to the open, above ground, end of the pipe to prevent

blocking by debris. Water fed directly into the system via a hosepipe will be placed

at exactly the correct location while waste through spillage and evaporation will be

minimised.

1.10 TREE SELECTION

1.10.1 The following issues must consideration when making a choice of trees for planting

adjacent to the public highway:

ultimate mature height -

- small to approximately 10m

- medium to approximately 15m

- large greater than 15m


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- ultimate shape and spread in general, when planting adjacent to highways,

particularly where high sided vehicles regularly pass, it is preferable to select a

variety with relatively upright growth that will not require regular pruning or be

damaged by the passage of vehicles. Away from the immediate kerb line a

broader crown could be considered.

site conditions as long as the soil is free draining and near-neutral pH then

most commonly specified street trees will grow well. Exposure, particularly to

strong and cold winds, may be a problem for some trees particularly those with

large leaves, a weak branch structure or brittle wood.

species specific or varietal features which may be good or bad. For example, a

tree that has good spring flowers, autumn berries or autumn colour may be

positive features, while fruit that causes problems on footpaths or is attractive tochildren is likely to be considered negative qualities by some and should be

avoided in the public realm.

1.10.2 A list of trees suitable for planting adjacent to the highway in Newcastle upon Tyne,

and those that are not, is included in Section 4.

1.10.3 Size of Planting for street planting trees will be selected from one of the following

girth sizes:

Standard 8-10 cm where damage is unlikely, or the tree can be

adequately protected, and initial impact is not a

priority

Selected

Standard

10-12 cm the above comments apply

Heavy

Standard

12-14 cm likely to require protection in a public situation but

will provide a greater initial impact

Extra Heavy

Standard

14 -16 cm more resistant to casual damage and generally the

preferred minimum size in a public location


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Semi Mature 16-35 cm trees of this size will provide good resistance to

casual damage and provide excellent initial impact.

However they require specialist handling and greater

attention during the establishment period.

Mature 35 cm + the above comments apply.

1.10.4 It is generally accepted that the smaller a tree is at planting the quicker it will

establish and start into new growth. There is evidence to suggest that a small tree,

say 8-10 cm girth, growing quickly, will catch up with and initially overtake in size a

tree planted at, say 16-18cm. Smaller trees are also cheaper to purchase and to

plant.

Drawbacks to planting the smaller sizes include lack of immediate impact and ease

of damage through vandalism. (A tree with a girth of 17cm is 35 times stronger

than one with a 7cm girth, explained by the formula 0.0491 x d4 where d =

diameter).

Some genera are considered less tolerant of transplanting at larger sizes eg.

Beech, Birch and Oak. However, modern nursery practice and a greater

understanding of root preparation has improved the situation. If the tree is

purchased from a reliable source, size and type should not be a major factor in its

survival after planting.

For urban situations it is recommended that newly planted trees have a minimum

girth of 14cm. Where there is a high risk of damage then the minimum

recommended girth is 18cm.

1.10.5 Root Type - bareroot v. rootballed v. containerised these are the three choices of

root preparation available and on which a decision must be made at the time of

specifying the trees from the supplying nursery.

Each method has its advantages and disadvantages.

Bareroot trees are, usually, cheaper than other root types, especially as the trees

tend to be sold while younger and smaller. It is also generally accepted that,

providing correct nursery and subsequent handling practices are followed, a bare

root tree will establish quicker than any other type. This is largely because when a

tree is lifted for rootballing or containerisation (as opposed to a tree that has been


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grown in a container throughout its life) many of the fine roots are left behind and

have to be regenerated before the tree can take up moisture and nutrients.

Bareroot trees retain much of the essential fine root system if lifted, handled and

protected correctly in the nursery, during transportation and on site.

Bareroot supply is the preferred option for trees of 18cm girth and below. Abovethis, the advantages do not apply as rootballs are larger and to achieve a bare root

without much fine root loss would make the size of the root impractical for handling

and storage purposes. The damage caused to the roots is much less with the larger

rootball, the trees are well protected against drying out so handling and storage is

not so critical. Above 18cm girth a rootballed tree is the preferred option.

Both containerised and rootballed trees can be used to extend the planting season,

in theory a container tree can be planted at any time of the year but irrigation isessential (see 13.01).

1.11 TREE GUARDS

1.11.1 The aim of tree guards is to reduce the likelihood of damage, either deliberate or

accidental.

The main requisite of any guard is that it is fixed rigidly vertical, usually by fixing

either to or under a grille, and of sufficient height to reduce the likelihood of the tree

being snapped at the top of the stake or at arms height. The top edge should be of

a design that reduces the likelihood of damage to the tree by chafing. Tree guards

used within the City of Newcastle upon Tyne will be selected from the Greenleaf

range or similar to approval (see appendix 1)

Where damage from manoeuvring vehicles is likely, such as car parks or on a verge

where vehicles habitually park, a raised kerb detail surrounding the planting pit is to

be used. (see Diagram No.5)

1.12 TREE GRILLES & PIT SURFACING

1.12.1 In a highway or street situation where trees are not planted in a grass verge or

shrub bed, there are three options for the surface of the planting pit - bare soil,

decorative grille or a porous aggregate.

1.12.2 Bare soil has inherent problems. It needs regular maintenance to keep it weed-

free, the surface is likely to become compacted and sink below the surrounding

paving level and, in suburban areas particularly, is likely to become a dogs latrine.


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1.12.3 Decorative grilles, either metal or plastic polymer, give protection to the soil around

the base of the tree. Polymer types have the advantage of not rusting or changing

colour and they have no scrap value, but limitations of the material and the

manufacturing process result in a restricted range of patterns and designs. Thereare virtually no limitations to the patterns of metal grilles.

Where site conditions allow, it is generally better to use the largest size grille

possible, thus maximising the amount of surface water reaching the planting pit.

This is only of benefit during the early years of the tree. Once the roots extend

beyond the area of the pit the area of open grille is of limited benefit to the tree and

its function is mostly decorative.

Unless future removal or an exchange of grilles can be guaranteed, it is also wise toavoid a small central aperture. While a larger opening, a minimum diameter of 400

mm is recommended, may appear too large at the time of planting it will allow room

for trunk growth. Some grilles are supplied with inner rings that may be removed to

accommodate the increase in stem girth. It is essential that grilles, of any material,

be supported by a frame which, in turn, is supported on at least two sides. Laying

the grille, with or without a frame, directly onto the soil of the planting pit will,

eventually, result in an uneven surface as the soil sinks in the pit.

Where a guard is to be used it is important that the design is compatible with the

grille and integral fixings are provided.

1.12.4 For trees in the adopted highway the pit surface is to be finished with a porous resin

bound aggregate with no grille. Where regular vehicular overrun is likely the

addition of a honeycomb cell matrix that provides additional rigidity and support is

required.

This system requires careful handling by the contractor in order to ensure the

correct mixing of the resin binder and aggregate. Manufacturers instructions must

be strictly adhered to. (see Appendix 1 and Diagram No.s 1B,2D, 4,5 & 6)

1.12.5 Where trees are to be planted into a bitumen macadam surface then the area

surrounding the pit surface and overlying the soil into which the roots will grow

should be constructed using an open-textured permeable bitmac. This will be a

60mm thick wearing course of 10mm aggregate laid over no-fines aggregate or a

porous no-fines concrete.


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1.13 THE PLANTING PROCEEDURE

1.13.1 Planting time - it is generally accepted that the planting season for trees runs from

mid November to mid March, when deciduous trees remain dormant. Rootballing,

cold storage and containerisation can, to some extent, extend this period. Howeverany tree planted after early March will be on the verge of coming into leaf. Additional

stress, through root damage or drought, at this critical period will lead to poor leaf

and root development from which the tree may never recover. Death, though not

inevitable, may occur some years later and be beyond the contract defects period.

Any planting beyond the March deadline must only be carried out if a

comprehensive and regular irrigation programme can be guaranteed. As a general

rule tree planting must only take place between mid November first week ofMarch.

1.13.2 Planting depth - The depth must be measured against the tree, either by trial and

error for a tree that is easily lifted or by measuring from the base of the rootball to

the collar at the base of the trunk where it starts to thicken out above the roots. A

straight edge laid horizontally over the pit, edge to edge, will provide a gauge by

which to judge the correct depth. Traditionally trees have been planted at a depth

indicated by the nursery mark, a dark area of stem extending above the root zone.

Recent research shows that this is not a reliable indicator of the correct planting

depth and may be the cause of many tree deaths. (Bib) This mark must not be used

as a method of establishing the correct planting depth.

1.14 AFTERCARE & MAINTENANCE

1.14.1 Maintenance of newly planted trees for at least 3 years, after planting is essential to

their long term survival and growth. Larger trees in particular, those above 25 cm

girth, can take several years to finally die, living off stored resources rather than

newly acquired ones. A guarantee period of at least 3 years, 5 years for trees of 35

cm girth and above, must be imposed on all new tree planting.

1.14.2 Incorrect handling at any stage of the works, failure to prepare the planting pit

correctly, poor planting techniques and lack of moisture at first bud-burst can lead

to poor establishment during the first 12 months of the tree in its new position. A

tree may be in leaf at the end of its first growing season but unless it has made


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sufficient growth to sustain it well into the next season it is likely to be on a

downward spiral from which there is no return. A tree showing lack of vigour at the

end of its first growing season should be treated the same as a dead tree and

scheduled for replacement.

1.14.3 Operations to be carried out during the maintenance period must include:

- Watering a minimum of 90 litres / tree shall be applied at fortnightly

intervals between the period 1stMay to 30thSeptember. If April is dry, newly

planted trees should be watered during this month at the same frequency. If

particularly wet weather occurs, supplementary watering may be

unnecessary. The use of larger quantities of water at greater time intervals is

not an adequate alternative and is not acceptable.- Pruning at the time of planting any damaged branches must be cut back to

a main junction or stem. Also beneficial to the tree is the reduction of crown

growth by removing weaker side branches. At the end of the first season of

growth, any branches showing signs of dieback must be cut back to live

wood. Pruning must take place during the dormant period except for Prunus

species when mid-summer pruning is recommended to reduce the likelihood

of disease. Pruning cuts shall not be painted with any type of wound sealing

paint.

- Support Check trees for stability and if necessary re-tie or expose

underground supports to tighten the wires.

- Tree pits shall be kept clear of weeds and trees planted in grass must have a

bare circle of soil at least 1m in diameter maintained around the trunk. This

reduces competition from grass and the likelihood of damage from mowing

machines.

1.14.4 Long term management and maintenance of the trees should not be forgotten after

the defects period is complete. Monitoring of growth, and for damage by storm, by

vehicles or by vandalism should be carried out on a regular basis and any

necessary remedial action taken. Timber stakes must be removed three years after

planting and when the tree is showing signs of strong growth. Maintenance of an

area of bare soil around the base of the tree helps to reduce damage by mowers

and other grass maintenance equipment.


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2.00 THE PLANTING OPERATION A WORK SEQUENCE

2.01 Planting in existing ground

Prior to work commencing on site:

obtain service and utility information and complete a visual inspection forpossible constraints to the proposed scheme (para. 1.3.1)

carry out a risk management assessment for site operatives and users during

the entire planting and maintenance operations of the trees (para. 1.3.2)

consult existing residents / occupiers of adjacent properties and inform them of

the draft proposals and programme

make any necessary amendments to the proposals in response to comments

following the public consultationSite works:

excavate one tree pit to investigate soil quality and drainage and assess

surrounding ground conditions (para 1.4.1)

excavate that number of tree pits which can be planted during the same day.

Any open pits must not be left uncovered when operatives leave the site.

Provision must be made to cover open pits with a board and warning tape

erected around the area.where necessary carry out amelioration of the excavated topsoil, mixing on a

board outside the pit to obtain a homogenous mix (para 1.4.2)

where required install a drainage layer of clean stone and cover with a sheet of

geotextile material (para 1.7.1)

where instructed install the pit drainage system and connect to existing drains.

This work must be carried out in full consultation with City of Newcastle upon

Tyne Engineering Services departmentt.

where instructed, and adjacent to known service runs install a root director or

root barrier (see Diagram No. 4 & para 1.6.4)

check the correct depth of the excavated pit by use of a straight edge against

the stem of the tree, or by measurement if the tree is too heavy to lift easily (para

1.13.2). Remember to take into account any proposed surface treatment such as

tree grilles and increase the depth accordingly.

where no drainage layer has been installed break up the base of the pit with a

fork. Where no root director has been installed scarify the sides of the pit with a

fork.


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lower tree into the centre of the pit and ensure that it is set vertical.

check, with a straight edge that the tree is sitting at the correct depth. If it is not,

remove the tree and adjust the base levels accordingly.

staking:

- for bare root trees position the stakes / stake so that the root system is not

damaged, remove the tree and drive the stakes so that they are firm and to the

correct depth (see Diagram No.s 2A, 2B & 2C, para 1.8.3). Re-set the tree

between or adjacent to the stakes / stake.

- for rootballed trees position the stakes, for either above ground or below

ground systems, adjacent to but clear of the rootball and drive them until the

wires hold the tree firmly and vertically with no movement at the base of the

rootball (see Diagram No.s 1A, 1B, & 1D, para 1.8.3 & 1.8.7)backfill the pit with topsoil or topsoil / compost mix in layers 300 mm deep and

lightly firm each layer (para 1.5.2). With bare roots ensure that the soil is

carefully worked around the roots and air pockets are eliminated.

Install an irrigation / aeration pipe after backfilling to one third depth of the

rootball and install prior to completing the backfilling (para 1.9.3)

above ground stakes tie the tree to the stakes, at 600 mm above ground level

or just below the lowest branches of the tree depending on the system beingused, with rubber ties and spacers or canvas hosing (see Diagram Nos1E, 2A,

2B & 2C, para. 1.8.4), and cut off the top of the stakes if damaged during driving

or of excess length.

apply 25 ltrs of water over the surface of the pit (para 1.9.2)

install surface treatment if specified.

2.02 Planting in new ground

Prior to work commencing on site:obtain service and utility information and complete a visual inspection for

possible constraints to the proposed scheme (para 1.3.1)

carry out a risk management assessment for site operatives and users during

the entire planting and maintenance operations of the trees (para 1.3.2)

consult existing residents / occupiers of adjacent properties and inform them of

the draft proposals and programme

make any necessary amendments to the proposals in response to commentsfollowing the public consultation


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Site works:

excavate the area to be topsoil to at least 1.1m deep (final depth will require an

allowance for the thickness of the specified paving / surface treatment) (See

1.4.4 for required topsoil volumes).

install a drainage layer, 200 mm deep of clean stone and cover with a sheet of

geotextile material (para 1.7.1) If necessary, install pipe drainage from the base

of the stone layer and connect to an adequate outflow point.

where specified and where there are adjacent foundations or services install a

root barrier at least 1.2m deep to the sides of the pit, ensuring 300 mm overlap

at joints, or root protector (see Diagram Nos 4 & 6, paras. 1.6.2 & 1.6.4)

install approved topsoil or, if specified, load-bearing tree soil into the planting

area in 300 mm deep layers. Topsoil must be lightly compacted by treading eachlayer prior to spreading the next layer. Tree soil must be compacted by using

an elephants foot type whacker plate - one pass over the entire surface of the

first two layers, two passes over the surface of the top layer, compacted to 2 kg /

cm2 and measured at a compaction of 0.2 with a penetrometer. (para 1.5.3)

after backfilling the planting area cover the topsoil with plastic sheeting or

tarpaulin to protect from wet weather until the finished surface is constructed.

excavate that number of tree pits which can be planted during the same day.Any open pits must not be left uncovered when operatives leave the site.

Provision must be made to cover open pit with a board and warning tape erected

around the area.

check the correct depth by use of a straight edge against the stem of the tree, or

by measurement if the tree is too heavy to lift easily (para 1.13.2). Remember to

take into account any proposed surface treatment such as tree grilles and

increase the depth accordingly.

lower tree into the centre of the pit and ensure that it is set vertical.

check, with a straight edge that the tree is sitting at the correct depth. If it is not,

remove the tree and adjust the base levels accordingly.

staking:

- for bare root trees position the stakes / stake so that the root system is not

damaged, remove the tree and drive the stakes so that they are firm and to the

correct depth (para 8.03). Re-set the tree between or adjacent to the stakes /

stake.


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- for rootballed trees position the stakes, for either above ground or below

ground systems, adjacent to but clear of the rootball and drive them until firm,

and for underground support systems until the wires hold the tree firmly and

vertically with no movement at the base of the rootball (see Diagram No.s 1A,

1B, 1D & 1E, para 1.8.3 & 1.8.7)

backfill the pit with topsoil or topsoil / compost mix in layers 300 mm deep and

lightly firm each layer (para 1.5.2). With bare roots ensure that the soil is

carefully worked around the roots and air pockets are eliminated.

Where an irrigation / aeration pipe is to be installed, backfill to one third depth of

the rootball and install prior to completing the backfilling (see Diagram No. 1A,

1B, 1C, 1D, 2D, 3B, para 1.9.3)

above ground stakes tie the tree to the stakes, at 600 mm above ground levelor just below the lowest branches of the tree depending on the system being

used, with rubber ties and spacers or canvas hosing (para 1.8.4), and cut off the

top of the stakes if damaged during driving or of excess length.

apply 25 ltrs of water over the surface of the pit (para 1.9.2)

install surface treatment if specified.


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PART 3

3.00 SPECIFICATION

Contents: 3.1 General Specification and Requirements for Tree Planting

3.2 Planting Bareroot Trees (general guidance)

3.3 Packaging and Handling of Semi-Mature Trees

3.4 Post Planting Maintenance and Aftercare

3.5 Rootballed Trees in Grass or Shrub Areas Underground Support

3.6 Rootballed Trees in Paving Underground Support

3.7 Rootballed Trees in Grass or Shrub Areas Double Stakes

3.8 Bareroot Trees in Grass or Shrub Areas Triple Stakes with Mesh

Guards

3.9 Bareroot Trees in Paved Areas Triple Stakes with Mesh Guards

3.10 Bareroot Trees in Grass or Shrub Areas Single and Double Stakes

(no tree guard)

3.11 Trees in Paving Resin Bound Aggregate Surface Finish to Tree Pit

including Raised Edge Surround

3.12 Trees in Paving Construction of Reinforced PavingSurround

3.13 Trees in Paving Root Barrier / Root Director


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3.00 SPECIFICATIONS

3.1 GENERAL SPECIFICATION AND REQUIREMENTS FOR TREE PLANTING

The following British Standards apply:

BS 4428:1989 Code of practice for general landscape operations (excluding hardsurfaces)

BS 4043:1989 Recommendations for transplanting root-balled trees

1. PLANTING SEASON & CONDITIONS

Carry out the work while soil and weather conditions are suitable for the

relevant operations. Bare root and rootballed trees should normally only be

transplanted during the recognised dormant season beginning of November tothe end of February.

Planting outside the period above - it may be possible to plant bare root or

rootballed trees in March but this is dependent on the tree species involved and

the prevailing weather conditions and adequate provision of watering. There

must be no assumption that planting can be continued after February and the

Contractor will seek advice if programming of works dictates planting at this

time of the year.

Tree planting between April and November - usually only possible by using

container grown material. The tree will be in leaf and adequate provision must

be made for irrigation at the time of planting and for continuing throughout the

summer months.

2. MACHINES AND TOOLS

Use only machinery and tools suitable for the site conditions and the work to be

carried out. Use hand tools around trees, plants and in confined spaces where it

is impracticable to use machinery.

3. WATER

to be provided for watering-in immediately following planting at 25 ltrs. / tree


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4 NOTICE PRIOR TO PLANTING

Make advance arrangements with the Client to give him the opportunity of being

present during:

Setting out

During excavation of the tree pits.

Planting of trees into previously dug pits

Each site visit during maintenance period.

5 STORAGE

Plants which are not to be planted on day of delivery to site to be stored as follows:

Root balled plants: Place close together and cover root balls with sand, moist

compost/soil or wet straw.

Bare root plants: for short periods, up to three days, they can be stored in

strong black plastic bags in a cool location. For longer periods the roots must be

temporarily covered by soil in a shallow trench (heeled-in)

6 TRANSPORTATION AND MOVING TREES -

In accordance with BS 4043:1989.

Machinery for moving the trees must be appropriate for the size and weight ofthe trees.

Supporting slings must be located under the rootball, not around the stem.

Branches to be tied in to avoid damage during transport.

7. DELIVERY -

All trees must be stacked in such a way that breakage or crushing, by weight of

the trees above or the securing of ropes will not occur.Where an open vehicle is used for delivery the whole consignment of trees must

be completely covered with opaque windproof sheeting and secured.

Trees must not be transported by rail or post.

Mishandling of trees during lifting, packaging or delivery resulting in damage to

the root system or aerial parts of the tree may result in rejection after re-

inspection of the trees on arrival at the landscape contractors nursery or the

site.


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8. TREATMENT OF WOUNDS

any minor damage that occurs to branches during handling shall be cut cleanly

back to sound wood using sharp, clean tools. Position cuts so that water will not

collect on the cut area.

Do not apply fungicide or sealant unless instructed by the Contract

Administrator.

Major damage to branches or damage to the trunk must be reported immediately

to the CA and the tree should remain unplanted, but with the roots protected,

until an inspection has been made and a decision made on whether to replace

the tree.

10 PROTECTION OF SURROUNDING GRASS existing grass during planting operations by laying boards or sheeting. Do not

place excavated material directly on to grass.

11. TREE PIT CONSTRUCTION

excavate by hand or mechanical means to the sizes quoted in the detailed

specifications. Ensure that the base of the pit is broken up and the sides are

scarified.Do not excavate pits during periods of extreme weather or allow the pits to fill

with standing water. If, after excavation, water appears to be rising into the base

of the pit inform the CA and wait for further instructions. A tree shall not be

planted into a site where there is a high water table or other drainage problems

unless adequate drainage can be provided.

12. PLANTING

protect bare root trees during the planting operation. Roots must be kept

covered by sacking or polythene to prevent from drying out.

Immediately after planting water the tree root area with approximately 25 litres

of water to ensure that the contact between the root or rootball and the planting

soil is uniformly moist.

Refer to the applicable specification for details of planting the root type being

used.


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13. CROWN PRUNING AT PLANTING

Unless previously carried out by the supplying nursery provision should be made

for thinning the crown of the tree at the time of planting by up to 25% or as

directed by the Contract Administrator. Thinning should be made to lateral

branches and weak side growth. The leading shoot must not be pruned.

14. SURPLUS MATERIAL

including subsoil, stones, debris, wrapping material and prunings to be removed

from site. Leave the site clean and tidy.


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3.2 SPECIFICATION -PLANTING BAREROOT TREES (GENERAL GUIDANCE)

BS 4043 applies.

1. PIT SIZE AND CONSTRUCTION -

Pits: shall be 300 mm wider than the spread of the root and with a minimum size

of 800 x 800 mm. Minimum excavated depth of 600 mm. Where necessary the

depth shall be increased to accommodate the depth of the root and to obtain the

correct planting level.

Break up bottom of pit to 150 mm deep and scarify the sides of the pit with a

fork.

2. PLANTING -Protective packaging trees must be delivered to site covered and the roots

protected from desiccation at all times and shall be removed from the packaging

immediately prior to planting. Trees whose roots show signs of having been

damaged or drying out should be rejected and returned to the supplier.

Horticultural Trade Association advice requires that bare root trees must be

placed into co-extruded bags immediately they are lifted. The tree must be

stored in the co-extruded bags, delivered, and kept on site in the same bags.(Co-extruded bags are white inside and black on the outside and made from

heavy gauge polythene).

Trees which are delivered to site in an unprotected or insufficiently protected

manner must be rejected and returned to the supplier.

After excavation, but before driving the stakes, hold the tree in the pit to assess

the correct depth. A straight-edge laid horizontally across the pit from each side

will enable the correct position of the root collar to be established in relation to

the existing ground level.

Plant trees upright and, unless otherwise instructed, in centre of pit.

Backfill the pit to a sufficient depth so as to support the tree at the correct level.

Planting depth the natural thickening between the trunk and the root collar

shall be at the top surface of the surrounding soil.

Establish the position of the stake or stakes so as not to interfere with the roots,

remove the tree then drive the stakes to make them firm. Burred or split stakes

shall be cut off at a point below the damage.


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Locate the tree at the correct level and, in paved areas or in mown grass, fit an

irrigation/aeration pipe.

Backfill the pit with specified material in 150 mm layers, shaking the tree slightly

to ensure thorough and even distribution through the roots. Tread the last two

last layers lightly to consolidate.

Fix the tree to the stake using a proprietary tree-tie with a spacing device to

prevent the tree rubbing against the stake. The tie shall be nailed to the stake

with one galvanised clout nail, minimum 25 mm long and with 10 mm heads, to

prevent the tie slipping.

3. DRAINAGE & AERATION UNIT -

Proprietary system installed in accordance with the manufacturers instructions or60 mm perforated plastic drainage pipe of sufficient length to encircle the

rootball at approximately 2/3rds depth and reach vertically to the surface of the

pit. A removable perforated end cap to be placed on the surface end of the pipe

to prevent blockage by debris.

4. SUPPORTING BAREROOT TREES:

Stakes: softwood, peeled chestnut or larch, free from projections and large edgeknots with one end pointed.

Minimum stake sizes:

Staking height / Tree size Overall Length of Stake Cross Section of Stake

Light Standard / Heavy

Standard -

at approximately 1/3rd

height of tree above

ground level

1800 75 100 mm

Light Standard Heavy

Standard

at a point immediately

below the lowest branches

2700 75 100 mm


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Extra Heavy Standard and

above at approximately

1/3rd height of tree above

ground level

1800 100mm

Extra Heavy Standard

and above

at a point immediately

below the below the lowest

branches

2700 100 mm

5. WATERING:

At planting ensure that all trees are given at least 25 ltrs. of water, applied over the

surface of the planting pit, to ensure thorough soaking of the rootball and the

surrounding ground.

6. CROWN PRUNING

Unless previously carried out by the supplying nursery provision should be made for

thinning the crown of trees immediately prior to planting by up to 25%. Thinning

should be made to lateral branches and weak side growth and include the removal

of any damaged branches. The leader shoot must not be pruned.

7. SITE CLEANLINESS

Remove soil from all hard surfaces and grassed areas and leave the works in a

clean tidy condition at Practical Completion. Adjacent surfaces must be protected

during the course of the works by laying timber sheeting or heavy gauge polythene

onto which arisings can be temporarily placed.


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3.3 SPECIFICATION FOR THE PACKAGING AND HANDLING OF SEMI-MATURE

TREES

1. PACKAGING

Packaging must be adequate for the protection of the trees and such as to

avoid heating-up or drying-out and must conform to the following:-

Root-balled and container grown trees must not be bundled.

Root-balls must be moist, supported by elastic banding, string netting or

stronger material where required to prevent collapse. The rootball must be

protected against drying-out by wrapping firmly with moisture retentive, porous

material such as sacking. Where wire-netting is used to support the rootball,

any moisture-retentive material must be outside the netting.All extra heavy standard, heavy standard, selected standard and standard trees

must be individually packaged.

Each packaged tree must be individually labelled with species, variety size and

where appropriate the quantity, whether bare-root, root-balled or container

grown.

Lateral branches and the head of the tree must be tied-in with ribbon or other

supple materials, but not coarse string which can cut into the bark, to protect thecrown from damage during handling and delivery and the planting process.

2. DELIVERY

All trees must be stacked in such a way that breakage or crushing, by weight of

the trees above or the securing of ropes will not occur.

Where an open vehicle is used for delivery the whole consignment of trees must

be completely covered with opaque windproof sheeting and secured.Trees must not be transported by rail or post.

Mishandling of trees during lifting, packaging or delivery resulting in damage to

the root system or aerial parts of the tree will be subject to rejection, upon re-

inspection of the trees on arrival at the landscape contractors nursery or the

site.


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3.4 SPECIFICATION - POST PLANTING MAINTENANCE AND AFTERCARE

The period of time for which the contractor is responsible for the defects and

maintenance of the tree shall be a minimum of 3 years unless otherwise specified.

1. PLANTING MAINTENANCE

During the Defects Liability Period and specified maintenance period carry out the

following operations:

Make visits at approximately monthly intervals during the growing season and as

necessary to fulfil the requirements of this specification.

Inform CA at least three days in advance of any maintenance operations to beundertaken.

During the maintenance visits carry out the following checks:

Check condition of stakes, ties, guys and guards. Replace broken or missing

items and adjust ties if necessary to prevent rubbing of bark.

Trees that are supported by underground guys should be checked for stability. If

necessary the wires will need to be exposed and tightened.

Cut back any damaged bark to a clean healthy area.Trees in grass must be kept clear of grass or weed growth over an area of 1m

diameter for trees up to 30cm diam. girth, 2m diameter for bigger trees, by hand

during the first year after planting or by approved herbicides during subsequent

years.

Prune trees to remove dead or dying and diseased wood and suckers and to

promote healthy growth and natural shape. Pruning should take place between

November and the end of February or early July to early August. Vandalised,ripped and hanging branches shall be removed immediately whatever the time

of year.

2. WATERING

Water as indicated below. Visits to be recorded and CA informed.Once during the

maintenance period, in March or April, apply liquid fertilizer to each tree, in

accordance with the manufacturers instructions.

during the establishment period arrangements should be made to provide at

least 90 litres of water per tree at fortnightly intervals during the period


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1stMay to 30thSeptember unless weather conditions dictate otherwise. It may

be necessary to commence watering earlier during a dry Spring. Where fitted,

watering should be via the irrigation pipe otherwise over the area of the planting

pit.

3. FAILURES OF PLANTING

Where the contractor is responsible for the replacement of trees that die during the

specified maintenance period the following shall be applied:

Any trees which are dead, dying or otherwise defective at the end of the Defects

Liability Period will be regarded as defects due to materials or workmanship not

in accordance with the Contract. They must be replaced by approved equivalent

trees at the next suitable planting season unless otherwise instructed. This willnot apply if the defects are caused by malicious damage after Practical

Completion unless stated otherwise in the Contract.

The Defects Period for trees up to and including Standard size will be 12

months.

The Defects Period for semi mature trees will be 36 months.

All trees will be assessed for growth throughout the defects period. A detailed

inspection will be undertaken during July/August, reporting by 31stAugust each

year, of the first, second and third year of the defects period. If, in the opinion of

the CA, the trees are dead, making insufficient growth or showing crown die-

back, or have a percentage of dormant buds over and above that which could

reasonably be expected, then they shall be replaced under the Defects Liability

and to all relevant specifications.

If it becomes necessary to replace a tree or trees the Contractor will be required

to arrange for the protection of all paved and grass areas surrounding the trees

and on the access to them, and for lifting and reinstating tree grilles and guards

if fitted. Protection for surrounding areas will be by the use of plywood boards

and sheeting of sufficient dimensions to cover the area of the work.

After replanting, damaged areas of whatever material will be reinstated to the

satisfaction of the CA.


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3.5 SPECIFICATION ROOTBALL TREES IN GRASS OR SHRUB AREAS,

UNDERGROUND SUPPORT

BS 4043 & BS 4428 apply

Refer to Diagram No. 1A and 1C1. PIT SIZE AND CONSTRUCTION -

Pits: shall be 600 mm wider than the diameter of the rootball with a minimum

size of 900 x 900 mm. Minimum depth to be 750 mm. Where necessary the

depth shall be increased to accommodate the depth of the rootball and to obtain

the correct planting level. Break up bottom of pit to 150 mm deep and scarify the

sides of the pit with a fork.

2. PLANTING

Remove any moisture-retentive material used to prevent the rootball drying out

during transport from the nursery but protect the rootball from sun and wind

during the planting operation.

Move the wire mesh support and root packing away from the trunk of the tree

but do not cut away from the main rootball, the integrity of the wire mesh must

not be damaged. Do not cut the wire mesh.



shall be at the finished top surface of the planting medium. A straight edge

placed across the pit at finished surface level and adjacent to the tree will assist

in gauging the correct level. If necessary, the depth of the pit must be adjusted

to ensure the correct planting level.

Install below-ground irrigation and aeration system e.g. Greenleaf Root Rain

Urban ensuring that the top of the filler pipe is flush with finished surface levels.

Backfill around the rootball with specified material in 150 mm layers, treading

lightly to compact each layer to a level approximately halfway up the side of the

rootball.

The underground support should be installed prior to completing the backfilling

of the pit.

Immediately after planting the tree shall be watered with approximately 25 ltrs. of

water to ensure that the contact of soil between the rootball and backfill material

is uniformly moist.


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3. UNDERGROUND SUPPORT-

Driven stake system (Diagram No. 1A) -

1 No. underground support per tree for trees up to 8m high. For trees 8m and

above two support systems should be used.

Stake and wire system comprising of 3No. timber stakes, 1.75m long x 75-

100mm diam., peeled but untreated with preservative and free of knots likely to

cause weak points. Galvanised wire, 5mm diam. multi-strand attached to each

stake with staples and to form a triangular cage over the rootball.

Stakes shall be at equi-distant spacing around the rootball and driven at an

angle under the rootball leaving at least 500 mm above the level of the pit for

final tensioning. Attach the wire as described, bringing it as tight as possible bymeans of fencing pliers or similar. Final tightening of the wire over the top

surface of the rootball mesh is achieved by continuing to drive the stakes until

the wire is as tight as possible.

After final tightening the top of the stakes shall be cut off below finished surface

level.

For trees in excess of 8m high the above specification applies but with the use of

two independent kits per tree i.e. 6No. stakes.Where ground conditions below the pit prevent the use of driven timber stakes then

one of the following may be employed -

Ground anchorage system such as:

Platipus Systems Rootball Fixing Kit

Supplied by Platipus Anchors Limited, Perrywood Business Park, Honeycrock Lane,

Salfords, Nr Redhill, Surrey RH1 5DZ Tel: 01737 762300

All work to be manufacturers instructions.

Deadman System (Diagram No. 1C)

1 No. underground support system comprising:

2No. deadmen located at opposite sides of the rootball. Deadmen shall be timber

or concrete, rectangular in section and of sufficient mass to prevent movement

when

buried below the soil. (For example, for a tree 5m tall a timber deadman should

have a section approximately 150mm wide x 100mm thick x 1200 long.)

The deadmen and wire must be fixed prior to backfilling the pit or placing the tree.


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5mm diam. multi-strand wire stapled around each deadman shall be tensioned by

turnbuckle or ratchet devices after the tree is in its final position.


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3.6 SPECIFICATION ROOTBALL TREES IN PAVING, UNDERGROUND

SUPPORT

BS 4043 & BS 4428 apply

Refer to Diagram No. 1A or 1C



size of 900 x 900 mm. Minimum depth of topsoil to be 900 mm, the depth of the

excavated pit will be sufficient to accommodate the rootball and to obtain the

correct planting depth. Break up bottom of pit to 150 mm deep and scarify the

sides of the pit with a fork.

2. PLANTING

Any moisture-retentive material used to prevent the rootball drying out during

transport from the nursery must be completely removed prior to planting but

protect the rootball from sun and wind during the planting operation.

Move the wire mesh support and root packing shall be away from the trunk of

the tree but do not cut away from the main rootball, the integrity of the wire mesh

must not be damaged. Do not cut the wire mesh.





in gauging the correct level. If necessary, the depth of the pit must be adjusted

to ensure the correct planting level.


lightly to compact each layer to a level approximately halfway up the side of the

rootball.

The underground support should be installed prior to completing the backfilling

of the pit.

Immediately after planting the tree shall be watered with approximately 25 ltrs. of

water to ensure that the contact of soil between the rootball and backfill material

is uniformly moist.


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3. UNDERGROUND SUPPORT -

Driven stake system (Diagram No. 1A)

1 No. underground support per tree for trees up to 8m high. For trees 8m and

above two support systems should be used.

Stake and wire system comprising of 3No. timber stakes, 1.75m long x 75-

100mm diam., peeled but untreated with preservative and free of knots likely to

cause weak points. Galvanised wire, 5mm diam. multi-strand attached to each

stake with staples and to form a triangular cage over the rootball.

Stakes shall be at equi-distanct spacing around the rootball and driven at an

angle under the rootball leaving at least 500 mm above the level of the pit for

final tensioning. Attach the wire as described, bringing it as tight as possible by

means of fencing pliers or similar. Final tightening of the wire over the topsurface of the rootball mesh is achieved by continuing to drive the stakes until

the wire is as tight as possible.

After final tightening the top of the stakes shall be cut off below finished surface

level.

For trees in excess of 8m high the above specification applies but with the use of

two independent kits per tree i.e. 6 No. stakes.

Where ground conditions below the pit prevent the use of driven timber stakes thenone of the following may be employed -

Ground anchorage system such as:

Platipus Systems Rootball Fixing Kit

Supplied by Platipus Anchors Limited, Perrywood Business Park, Honeycrock Lane,

Salfords, Nr Redhill, Surrey RH1 5DZ Tel: 01737 762300

All work to be manufacturers instructions.

Deadman System (Diagram No. 1C)

1 No. underground support system comprising:

2 No. deadmen located at opposite sides of the rootball. Deadmen shall be timber

or concrete, rectangular in section and of sufficient mass to prevent movement

when buried below the soil. (For example, for a tree 5m tall a timber deadman

should have a section approximately 250mm wide x 100mm thick x 1500 long.)

The deadmen and wire must be fixed prior to backfilling the pit or placing the tree.

5mm diam. multi-strand wire stapled around each deadman shall be tensioned by

turnbuckle or ratchet devices after the tree is in its final position.


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5. DRAINAGE / AERATION UNIT

The drainage / aeration pipe such as Greenleaf Root Rain Urban should be

installed after the underground support to prevent damage to the pipe.

The drainage / aeration pipe, 60 mm diameter, shall fully encircle the rootball at

approximately 2/3 rds its depth with a vertical tail reaching to the surface of the

pit. A removable perforated end cap should be used at ground level to prevent

debris blocking the pipe.

For semi mature trees with a rootball in excess of 1200 mm diameter the pipe

should form a spiral with at least two complete turns encircling the rootball.


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3.7 SPECIFICATION ROOTBALL TREES IN GRASS OR SHRUB AREAS,

DOUBLE STAKES

BS 4043 & 4428 apply.

Refer to Diagram No. 1E1. PIT SIZE AND CONSTRUCTION


size of 900 x 900 mm. Minimum depth to be 750 mm. Where necessary the

depth shall be increased to accommodate the depth of the rootball and to obtain

the correct planting level.

Break up bottom of pit to 150 mm deep and scarify the sides of the pit with a

fork.

2. PLANTING -

Remove any moisture-retentive material used to prevent the rootball drying out

during transport from the nursery but protect all roots from sun and wind during

the planting operation.

Move the wire mesh support and root packing shall be away from the trunk of

the tree but do not cut away from the main rootball, the integrity of the wire meshmust not be damaged. Do not cut the wire mesh.





in gauging the correct level. If necessary the depth of the pit must be adjusted to

ensure the correct planting level.


lightly to compact each layer to a level approximately one third up the side of the

rootball.

Install the double stake support system in accordance with the specification

below.

Immediately after planting the tree shall be watered over the soil surface with

approximately 25 ltrs. of water to ensure that the contact of soil between the

rootball and backfill material is uniformly moist


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3. DOUBLE STAKE SUPPORT-

Staking kit comprising 2No. stakes 2 m long x 70 mm approximate diameter and

2No. ties.

Stakes shall be peeled, free of stubs or large knots and untreated with

preservative.

Ties shall be either proprietary rubber strapping 25 50 mm wide or

rubber/nylon hosepipe.

Stakes shall be set at an equal distance from the trunk of the tree and clear of

the rootball. Use a pinch bar or similar to produce a vertical guide hole then

drive the stake until firm and at least 300 mm below the base of the tree pit. The

final height of the stake shall be approximately one third the clear stem height of

the tree.

Loop the tie around the trunk, one from each side of, and firmly nail to each

stake with 2No. galvanised clout nails. Ties to be fixed as tight as possible to

prevent the tree moving at the base of the trunk.


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3.8 SPECIFICATION BAREROOT TREES IN GRASS OR SHRUB AREAS -

TRIPLE STAKES

To be used for bare root trees with a stem girth of 18 cm or above

BS 4428 applies.

Refer to Diagram No. 2C


Pits: shall be 600 mm wider than the root spread of the tree with a minimum

width of 800 x 800 mm. Minimum depth to be 600 mm. Where necessary the


correct planting level.

Break up bottom of pit to 150 mm deep and scarify the sides of the pit with afork.

2. PLANTING -

Remove any moisture-retentive material used to prevent the root drying out



Prior to installing the stakes place the tree into the pit to check the correctplanting depth, that the pit can accommodate the fully spread root system and

place the stake / stakes in positions that will not damage the roots. Remove the

tree and cover the roots with protective material.

Install the stake support system in accordance with the specification below.

Plant trees upright and, unless otherwise instructed, in centre of pit, spreading

the roots carefully and evenly over the base of the pit.






Backfill around the root, gently shaking the tree will aid settlement and ensure

that no air spaces exist, with specified material in 150 mm layers, treading lightly

to compact each layer.


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roots and backfill material is uniformly moist.

3. TRIPLE STAKE SUPPORT -

Staking kit comprising 3No. stakes 2 m long x 70 mm approximate diameter and

3No. ties.


preservative.


rubber/nylon or canvas hosepipe.

Stakes shall be set at an equal distance from the trunk of the tree and clear of

the rootball and at equi-distant spacing. Angle each stake back from the vertical

by approximately 5 deg. Use a pinch bar or similar to produce a guide hole then

drive the stake until firm and at least 300 mm below the base of the tree pit. The

final height of the stake shall be approximately one third the clear stem height of

the tree.

Loop the tie around the trunk, one from each side of, and firmly nail to each

stake with 2No. galvanised clout nails. Ties to be fixed as tight as possible toprevent the tree moving at the base of the trunk.

After driving the stake, if the top has split or burred this should be cut back to

sound wood prior to fixing the tie.


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3.9 SPECIFICATION BARE ROOT TREES IN GRASS OR SHRUB AREAS,

TRIPLE STAKES WITH MESH GUARD

To be used for bare root trees in locations likely to receive high levels of

interference and damage.

BS 4043 appliesRefer to Diagram No. 3A

1 . PIT SIZE AND CONSTRUCTION -

Pits: shall be 600 mm wider than the root spread of the tree with a minimum

width of 800 x 800 mm. Minimum depth to be 600 mm. Where necessary the


correct planting level.Break up bottom of pit to 150 mm deep and scarify the sides of the pit with a

fork.

2 PLANTING


during transport from the nursery but protect all roots from the sun and wind

during the planting operation.

Prior to installing the stakes place the tree into the pit to check the correct

planting depth, that the pit can accommodate the fully spread root system and

place the stakes in positions that will not damage the roots. Remove the tree

and cover the roots with protective material.









Backfill around the root, gently shaking the tree will aid settlement and ensure

that no air spaces exist, with specified material in 150 mm layers, treading lightly

to compact each layer.


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roots and backfill material is uniformly moist.

3. TRIPLE STAKE SUPPORT -

Staking kit comprising 3No. stakes 2.7 m long x 70 mm approximate diameter

and 3No. ties.


preservative.


rubber/nylon hosepipe.

Stakes shall be set at an equal distance (approximately 300 mm) from the trunk

of the tree and clear of the rootball and at equi-distant spacing. Use a pinch bar

or similar to produce a vertical guide hole then drive the stakes until firm and at

least 300 mm below the base of the tree pit. The final height of the stake shall be

just below the lowest branches of the tree.

Loop the ties, at 400 mm below the top of the stakes, around the trunk and firmly

nail to each stake with 2No. galvanised clout nails. Ties to be fixed as tight as

possible to prevent the tree moving at the base of the trunk.After driving the stakes, if the top has split or burred this should be cut back to

sound wood prior to fixing the tie.

4. MESH GUARD

The guard shall be formed from a sheet of 50 x 50 mm x 2.5 gauge welded

mesh, plastic coated in black or green.

The mesh shall be fixed to the outside of each stake to form a cage 1500 mmhigh with a 200 mm gap at the base.

Fixing shall be with galvanised staples, 4No. to each stake at an equal distance

between the top and the bottom of the mesh.

The cut ends of the mesh must be bent back inside the cage to remove the

possibility of sharp snag ends.


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3.10 SPECIFICATION BAREROOT TREES IN GRASS OR SHRUB AREAS,

SINGLE AND DOUBLE STAKES (NO TREE GUARD)

BS 4428 applies.

Refer to Diagram No. 2A (single stake) & 2B (double stake)

1. PIT SIZE AND CONSTRUCTION

Pits: shall be 600 mm wider than the root spread of the tree. Minimum depth to

be 600 mm. Where necessary the depth shall be increased to accommodate the

depth of the root and to obtain the correct planting level. Break up bottom of pit

to 150 mm deep and scarify the sides of the pit with a fork.

2. PLANTING -




Prior to installing the stakes place the tree into the pit to check the correct

planting depth, that the pit can accommodate the fully spread root system and

place the stake / stakes in positions that will not damage the roots. Remove the

tree and cover the roots with protective material.








ensure t

tree design guide may 06

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