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Euphorbia

Final Trials Report

2013-2015

Written by Sue Drew Trials Office

The Royal Horticultural Society Garden, Wisley, Woking, Surrey, GU23 6QB

Final Report for Trial No. 1981 - Euphorbia 2013 – 2015 1

RHS Trial of Euphorbia

Introduction to Euphorbia Euphorbia is a genus of around 2,000 species of plant. They feature succulents, trees and shrubs, annuals, biennials, perennials and subshrubs. They vary from fully hardy to frost tender and can be found in a variety of different habitats in temperate, tropical and subtropical regions. Their milky sap can irritate skin and eyes so caution should be taken when handling them. They have small flowers held within cupped, often colourful bract-like cyathophylls. This trial focussed on plants suitable for year-round use in UK gardens. Trial Location The Trials Field at RHS Garden Wisley. Objectives The objectives of the trial were:

To judge for garden worthiness (Award of Garden Merit)

To demonstrate the range and use as garden plants

To compare established and new cultivars

To produce a permanent record through herbarium specimens, photographs and written descriptions for the RHS Herbarium at Wisley

Judging The Euphorbia Trials Assessment Forum assessed entries in the trial in 2013 (18 June, 17 September, 14 November), 2014 (20 March, 15 May, 29 July, 17 September, 20 November) and 2015 (26 February, 21 April, 30 June), recommending the Award of Garden Merit to plants using the following criteria:

Foliage quality

Length of flowering

Floriferousness

Habit / structure

Quality of flowering

Hardiness

Pest and disease resistance

Entries There were 95 entries in this trial, generally submitted as 2 litre plants by breeders, nurseries and individuals in the UK and Europe.

24 April 2013 – shortly after planting 21 May 2014 – fully established plants


Cultivation and findings 2013 The plants were kept in a frost free glasshouse prior to planting to protect them from the winter weather. Unfortunately planting had to be delayed due to cold weather. This delay in planting caused some of the plants to become drawn and a bit pot bound. Some also flowered early. The trial was planted out on 17 April 2013. Spacing was 75cm between plants and 100cm between entries or 100cm between plants and 100cm between entries, depending on the entry. Drip irrigation was installed on the site and the plants received water as and when necessary during their establishment. On 26 April 2013 supports were added to taller entries which had flopped over (due to being drawn prior to planting), to aid them whilst they established. Strulch was applied to the bed on 24 July 2013, avoiding the crowns of the plants. Strulch was used as a weed suppressant mulch. Whilst such a mulch was not considered necessary in the general garden situation, it was used on the trial to reduce the amount of weeding required. The Strulch was topped up during the course of the trial as necessary on 1 December 2013 and 12 March 2014. At the end of July 2013 a few plants had died and were taken to the RHS Plant Pathology for investigation. It was thought that these plants had been more susceptible to disease due to their stressful start in the trial. Cultivation and findings 2014 Although the trial plot was situated towards the top of a slope, it had been saturated from the prolonged heavy rain during the winter of 2013/2014. This meant that many entries had sat in puddles of water at varying times. Despite this, the trial looked very good in spring 2014. Due to wind and rain, a number of plants were unsteady in January 2014 and were staked as necessary. As a number of plants did not survive through 2013, replacements were planted during February and April 2014. E. x pasteurii and E. stygiana entries - an amazing honey-like perfume was noticed from these plants at the assessment meeting in May 2014. E. martini types – make very useful container plants and are often treated as long term bedding as they tend to live for 3-4 years. Entries were deadheaded as required during the trial. The dead flower spikes of all of the E. characias type entries were cut back on 23rd July 2014. Irrigation was used when necessary during the dry weather in July. Dead plants continued to be removed as and when necessary during 2014 and 2015. In November 2014 it was noted that although a number of the E. characias entries had died, a lot of other entries were performing very well.


Cultivation and findings 2015 In February 2015 it was commented that euphorbias should be giving their biggest contribution to the garden at this time of year. However, this was not the case with the trial due to issues with disease. The final assessment meeting of the trial took place on 30 June 2015. Pest and Disease The following plant pathogens affected some plants during the trial whilst they were in the Plant Reception glasshouse:

Botrytis cinerea – grey mould causing stem rots of glasshouse grown plants The following pests affected some plants whilst they were in the Trials Field:

Aphids - the trial was sprayed with Aphox and SB Plant Invigorator as necessary The following plant pathogens affected some plants during the trial whilst they were in the Trials Field:

Rust - affected the E. griffithii and E. margalidiana entries

Phytophthora (P. cryptogea, P. plurivora, P. citricola) - root / stem rot

Thielaviopsis - root rot

Pythium species - root / stem rot

Rhizoctonia solani - root / stem rot

Fusarium - root / stem rot Saturated soil such as that seen in the winter of 2013/2014 would create ideal conditions of pathogens such as Thielaviopsis, Phytophthora and Pythium to spread. Unfortunately no treatment is available for these diseases and resting spores can remain in the ground for a number of years. Where replacements plants were added to the trial, in order to reduce the risk from these diseases, existing soil was removed and fresh soil added in its place. Name change from E. polychroma to E. epithymoides The decision for the RHS to accept the name E. epithymoides as the correct name for E. polychroma was taken by the RHS Nomenclature & Taxonomy Advisory Group at their meeting on 13 June 2013. M.Sc. Research Project Oliver White, Reading M.Sc. student, carried out a research project in collaboration with the Royal Horticultural Society (RHS) and Mark Carine at the Natural History Museum (NHM). The project aimed to assess the genetic diversity of Macaronesian endemic Euphorbia species E. mellifera and E. stygiana, which are both widely cultivated in the UK. A garden hybrid E. x pasteurii has also been described when these two closely related species hybridise. These ex situ collections of Macaronesian Euphorbia species could potentially support threatened populations in the wild. The overall aim of this project was to assess the diversity of Macaronesian Euphorbia species cultivated in the UK, with the potential to make some insightful comparisons to the wild populations. As part of this project, leaf samples of a number of the trial entries were taken for DNA extraction. The results of this research were published (White, O. (2015). Honey-scented spurges and their hybrid. The Plantsman, March 2015: 42-47) and enabled some of the trial entry names to be corrected.


Plants Receiving AGMs During Trial The following are the plants thought to fulfil the Award of Garden Merit criteria during the trial and to be worthy of receiving the award. The criteria which a plant needs to fulfil in order to receive the award are:

excellent for ordinary use in appropriate conditions

available

of good constitution

essentially stable in form and colour

reasonably resistant to pests and diseases Hardiness ratings are as follows:

H4 = Hardy - average winter (-10°C – -5°C) H5 = Hardy - cold winter (-15°C – -10°C) H6 = Hardy - very cold winter (-20°C – -15°C) H7 = Very hardy (< -20°C)

Plants Awarded AGM

In the descriptions below, the number codes after the colour names refer to the RHS Colour Chart. Names that are struck through have been updated / corrected by RHS Botanists during the course of the trial.

Euphorbia 'Abbey Dore'

AGM (H7) 2015, (trial entry 4).

Sent by: Phoenix Perennial Plants, Paice Lane, Medstead, Nr Alton, Hampshire, GU34 5PR

Available

Forum comments: Flowers for a long time. Its yellowy-green colour is very welcome in mid-summer. Foliage very healthy. Regrows well from the centre. Semi-evergreen. Hardly runs at all.

Description: Habit: Upright to spreading, fairly open. Height x width (cm): 50 x 80. Foliage colour: Yellow Green 146B, appearing slightly glaucous. Leaf pubescence and features: Glabrous, matt. Stem colour, pubescence, etc.: Yellow green, flushed red at base; glabrous. Flower colour: Bright Yellow Green 151B, buds slightly greener N144B, glands 152D. Flower features: Pedicels green. Herbarium specimen collected on 21/05/2014.

17 April 2014 17 June 2015 5 June 2015


Euphorbia amygdaloides var. robbiae


Sent by: Walberton Nursery, Yapton Lane, Arundel, BN18 0AS (sent via Farplants)

Widely available

Forum comments: A useful and valuable garden plant. A nice, easy plant for dry shade. Invaluable under beech trees etc. Its flowers are very welcome in late winter. The deadheads go a wonderful russet-red / apricot colour when it sets seed.

Note: it can be invasive in some situations but is very easy to control.

Description: Habit: Compact round foliage. Height x width (cm): 50 x 60. Foliage colour: Darker Green N137A above and lighter 138B on lower side. Leaf pubescence and features: Glaucous leaves with a shiny surface on upper side and a leathery touch. Stem colour, pubescence, etc.: Red to Greyed-Orange 147B stem at base becoming more Yellow-Green 145 towards the terminal inflorescence. Sparsely hairy. Flower colour: Bracts Yellow-Green N144 D but with darker green patches in places. Glands Yellow-Green N144D. Flower features: One male flower, one female flower and two buds per bract. Pedicel sparsely hairy. Herbarium specimen collected on 27/03/2014.

16 April 2015 8 April 2015 28 October 2014

Euphorbia 'Whistleberry Garnet'


Sent by: Rijnbeek & Son Perennials (sent via Ronald Houtman)

Available

Forum comments: Very good new foliage in spring. Has red tinges to its foliage. Bees love it. Has splendid rusty / golden coloured dead flower heads.

Description: Habit: Upright bush, very floriferous. Height x width (cm): 70 x 80. Foliage colour: Yellow Mid Green, slightly yellower than 137B, midrib paler, sometimes red flushed on lower side; lower side of leaf/bracts in inflorescence also tinged Greyed Red 183D. Leaf pubescence and features: Glabrous except on basal edges, slightly dull and prunious. Stem colour, pubescence, etc.: Strongly flushed Greyed Red 184B with darker and lighter patches, especially in inflorescence; sparingly covered with long, fine wispy hairs. Flower colour: Involucre Yellow Green 146D with bluer green tint towards tips, perianth Yellow Green 144C, yellower on reverse, glands Reddish Brown 178B, turning paler and browner later. Flower features: Glands horned, shiny. Herbarium specimen


collected on 31/03/2014.

30 March 2015 1 May 2015 16 April 2015

Euphorbia x martini 'Helen Robinson'


Sent by: Cotswold Garden Flowers, Browns' Nursery, Gibbs Lane, Offenham, Evesham, Worcestershire, WR11 8RR (nursery at Sands Lane, Badsey, Worcestershire, WR11 7EZ)

Available

Forum comments: Beautiful leaf with nice, neat rosettes. Extremely effective as a winter plant. Looks amazing – healthy, neat, fresh and bright. Has a soft look and makes a very good foil for other plants.

Note: It can be invasive in some situations.

Description: Habit: Upright and dense, floriferous. Height x width (cm): 80 x 80. Foliage colour: Green 137B, maturing to N137A, paler 138B beneath. Leaf pubescence and features: Thickly softly hairy when young, becoming glabrous and sublustrous above; mid rib and petiole green. Stem colour, pubescence, etc.: Stem Greyed Red 181B-C, fading to Green 144D; shortly softly pubescent. Flower colour: Involucre and perianth Yellow Green N144A with one or two greener patches here and there; glands Greyed Red 178A. Herbarium specimen collected on 24/03/2014.

30 March 2015 1 May 2015 16 April 2015


Euphorbia x martini 'Ascot Rainbow'


Sent by: Madrona Nursery, Pluckley Road, Bethersden, Kent, TN26 3DD

Widely available

Forum comments: A good winter plant. Short lived perennial. Foliage has a delightful warm, peachy glow and the flowers are a pale creamy, green-yellow. Neat, a very good shape and a very useful height.

Description: Habit: Upright to slightly spreading mound. Height x width (cm): 85 x 90. Foliage colour: Greyish Green 147B, darker Green N137A patching on the occasional leaf, edges Yellow, grubbier than 16C, this flushed Red 53D in places; tips especially, under-surface greyed version of above. Leaf pubescence and features: Very finely hairy on both surfaces. Stem colour, pubescence, etc.: Green in upper inflorescence, becoming flushed RedPurple 187C, this streaked but becoming solid at base. Flower colour: Bracts Greyed Green 174B with broad margins of Yellow 11A, glands dark Red 187B, shiny. Flower features: Glands 'cat head' shaped. Herbarium specimen collected on 08/05/2015.

25 February 2015 1 May 2015 1 May 2015

Euphorbia characias 'Tasmanian Tiger' (PBR) (v)



Available

Forum comments: Looks amazing. Really good for a winter garden. Very neat, compact and robust. Good in pots. The only variegated E. characias type with vigour.

Note: Needs to be grown in a sheltered place to avoid leaves and flowers burning in the wind / sun.

Description: Habit: Chunky, low branching from central trunk. Height x width (cm): 55 x 80. Foliage colour: Greyed Green 189A-B strongly variegated, mostly on edges White 157D to Cream/pale Yellow 2D on fresher leaves, paler beneath. Leaf pubescence and features: Very finely hairy. Stem colour, pubescence, etc.: Grey green, tinged greyed red at leaf scars, very finely hairy. Flower colour: Involucre and perianth very pale Yellow 2D, glands slightly darker yellow, perhaps 3D. Herbarium specimen collected on 12/03/2014.


23 February 2015 8 April 2015 30 March 2015

Euphorbia characias subsp. characias 'Blue Hills'


Sent by: Worlds End Garden Nursery, Moseley Road, Hallow, Worcester, WR2 6NJ

Available

Forum comments: Lovely shape and character, good compact habit. Attractive narrow leaves. Green bracts with a stunning, glossy back eye.

Description: Height x width (cm): 90 x 100. Foliage colour: Green 137C above, beneath paler Green 139D but greyer. Leaf pubescence and features: Minutely hairy above, shortly woolly beneath. Stem colour, pubescence, etc.: Pale greyish Green slightly glaucous, lower stem lightly flushed Greyed Red 182C especially at leaf scars. Flower colour: Involucral bracts Yellow Green bluer than N144C becoming light towards base in patches, fused perianth bracts greyish Yellow Green, slightly greener than 145A, Older, basal floret gland Greyed Red 182B, whereas younger distal pair of florets' glands are Greyed Purple 187A. Flower features: Glands petaloid, developing ovary hairy appearing woolly. Herbarium specimen collected on 07/05/2015.

8 April 2015 16 April 2015 1 May 2015


Euphorbia characias subsp. wulfenii 'Jimmy Platt'



Available

Forum comments: Lovely pale midrib on the very narrow leaves – looks like a pinstripe. Has big, fat, yellow flower heads which are wider at the top than the base. Strong, vigorous plants. Looks lovely with dew on the blue foliage.

Description: Habit: Upright, bushy. Height x width (cm): 110 x 100. Foliage colour: Foliage bluish from a distance, above Green 137B, paler Geyish Yellow Green 138B beneath. Leaf pubescence and features: Very finely softly pubescent on most surfaces. Stem colour, pubescence, etc.: Green above to lightly streaked grubby pink Greyed Red 182C/D. Flower colour: Involucral bracts cuplike Yellow Green N144A overshot with Yellow Green 144B, younger glands Yellow Green 153A becoming Greyed Orange 168D. Flower features: Glands horned, inward curving. Herbarium specimen collected on 13/05/2015.

23 February 2015 16 April 2015 16 April 2015

Euphorbia margalidiana


Sent by: National Collection of Euphorbias, 26 Casson Drive, Harthill, Sheffield, S26 7WA

Available

Forum comments: Very floriferous with attractive bluish foliage. Incredibly healthy, evergreen plants. Large plants which have presence.

Description: Habit: Robust but tending to sprawl where unsupported, very floriferous. Height x width (cm): 120 x 180. Foliage colour: Mid Green N137C, greyer 191B beneath, leaves below inflorescence becoming Yellow 6C at base. Leaf pubescence and features: Glabrous, matt. Stem colour, pubescence, etc.: Green, becoming yellower in inflorescence, glabrous. Flower colour: Involucre and perianth Yellow Green N144A mid, Yellower Green 151D edges, glands dullish Yellow Green 152D becoming Yellow 21B later. Flower features: Pedicels green, glabrous. Herbarium specimen collected on 12/05/2014.


25 February 2015 1 May 2015 1 May 2015

Euphorbia ceratocarpa


Sent by: National Collection of Euphorbias, 26 Casson Drive, Harthill, Sheffield, S26 7WA

Available

Forum comments: Phenomenal flowering – normally flowers for most of the year. Really useful plants. Looks extraordinary in winter.

Three treatments were applied to this entry. One plant was cut to the ground completely, one had half of its older shoots removed and the other was un-touched. The plant which was cut do the ground completely did not regrow but the other two performed well.

Description: Habit: Tall upright, lanky, shrub becoming woody. Height x width (cm): 160 x 180. Foliage colour: Glaucous green 137A with mid and smaller veins, paler Yellow Green 145B above, Greyed green 191A below, paler mid-vein as above. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Glabrous. Young stems Green 145A, older stems flushing increasingly Greyed Orange 172A. Flower colour: Bracts Yellow Green base over shot towards tips Green 137A above, Green 138B, but paler beneath, bracts subtending flowers Yellow Green N144A above Yellow Green 151A below, Glands Yellow Green N144A younger and Yellow green 153A in older flowers. Flower features: Glands petal-like, convex and sticky. Herbarium specimen collected on 21/05/2015.

15 May 2014 17 June 2015 25 February 2015


Euphorbia nereidum


Sent by: University of Oxford Botanic Garden, Rose Lane, Oxford, OX1 4AZ

Available

Forum comments: More architectural than most euphorbias, very imposing. Ginormous here, has 6ft long stems. Good for the back of a border. Nice pinkish stems. Usually gets hit by the cold in the winter but it always comes back.

Description: Habit: Tall and upright, tending to flop where unsupported. Height x width (cm): 200 x 180. Foliage colour: Green c. 138A with paler veins, slightly greyer beneath. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Green, glabrous. Flower colour: Involucre Yellow Green N144C, paler N144A especially about edge, perianth Yellow Green 151A, glands 153A. Flower features: Gland segments square with rounded corners in outline. Herbarium specimen collected on 09/06/2014.

17 June 2015 17 June 2015 27 October 2014

Euphorbia stygiana Euphorbia x pasteurii


Sent by: Sampford Shrubs, Sampford Peverell, Tiverton, Devon EX16 7EN

Available

Forum comments: Good colour - a vivid, lively green. Like the way you can see the pale underside of the leaves, it provides a good contrast. Good shape plants. Has orange nectaries.

Description: Habit: Robust stems, open, spreading. Height x width (cm): 125 x 150. Foliage colour: Yellow Green 144A but greener, mid-vein Yellow Green 145C, margins in older leaved lined finely with Greyed red 178A above, Green 139D below. Leaf pubescence and features: Glabrous, margins curving under. Stem colour, pubescence, etc.: Yellow Green 145A in young stems lightening to Yellow green 145A in older, some flush of Red Purple 60C at base, glabrous. Flower colour: Perianth bracts small, insignificant, Yellow Green 154C, long hairs, strigose/tomentose, outer younger glands Yellow Green 146A but darker, central older gland Greyed Orange N163C/162A. Flower features: Glands petal-shaped, developing ovary with scattered warty protrusions along outer carpellary edge, Yellow Green N144C. Herbarium specimen collected on 21/05/2015.


1 May 2015 21 May 2015 28 October 2014 25 February 2015

Euphorbia 'Roundway Titan' Euphorbia x pasteurii 'Roundway Titan'


Sent by: Brockhill Nursery, Sway Road, Tiptoe, Lymington, Hampshire, SO41 6FR

Available

Entries 89, 90, 91, 93 & 94 all looked very similar and incredibly uniform. The following Forum comments apply to all of these entries: Fantastic architectural plants. The red foliage and coral stems in winter (caused by the cold) can be very attractive.

Description: Habit: Robust, upright spreading rounded shrub. Height x width (cm): 100 x 165. Foliage colour: Yellow Green 144Ain bracts and leaves below inflorescence and darker Yellow Green 146Ain lower leaves, mid-vein Yellow Green 145B/C veins and edge margins also paler in some leaves - above, Green 139D almost below, margins in older leaves lined Orange Red N34A, some older leaf blades tinged Orange 24B/ Orange Red 34AYellow Green 144Ain bracts and leaves below inflorescence. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Yellow orange 14C / Yellow Green 154B/C. Flower colour: Perianth bracts small, insignificant, Yellow Green 154C, long hairs, strigose/tomentose, outer younger glands Grey Brown 199A but central gland Greyed Orange N172C turning darker Brown N200A as they age. Flower features: Glands petal-shaped, developing ovary with scattered warty protrusions along outer carpellary edge, Yellow Green N144A. Herbarium specimen collected on 28/05/2015.

21 May 2015 21 May 2015 25 February 2015


Euphorbia x pasteurii 'Phrampton Phatty'


Sent by: RHS Garden, Wisley, Woking, Surrey, GU23 6QB

Available


Description: Habit: Erect robust shrub, outspread. Height x width (cm): 100 x 175. Foliage colour: Yellow Green 144Ain bracts and leaves below inflorescence and darker Yellow Green 146Ain lower leaves, mid-vein Yellow Green 145B/C veins and edge margins also paler in some leaves - above, Green 139D almost below, margins in older leaves lined Orange Red N34A. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Yellow green 151B/ Greyed yellow 160A. Flower colour: Perianth bracts small, insignificant, Yellow 3C to Yellow Green 144C, edged with hairy tufts, outer younger glands Grey Brown 199A but central gland Greyed Orange N172B/D turning darker Brown N200A as they age. Flower features: Glands petal-shaped, developing ovary with scattered warty protrusions along outer carpellary edge, Yellow Green N143B. Herbarium specimen collected on 28/05/2015.


Euphorbia x pasteurii 'John Phillips'


Sent by: RHS Garden, Wisley, Woking, Surrey, GU23 6QB

Available


Description: Habit: Erect, robust, spreading. Height x width (cm): 110 x 160. Foliage colour: Yellow Green 144A bracts below inflorescence, leaves Green 137A/, mid-vein Yellow green 145B above, Green 138B/C below, margins in older leaves lined Orange Red N34A. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Yellow green 145A in younger stems lightening to Yellow green 145B in older, some flush of Red Purple 60C in places, glabrous. Flower colour: Perianth bracts small, insignificant, older are Yellow Green 154C to Yellow Green 144D, strigose in some edged with woolly hairy tufts, outer younger glands Yellow Green 152A but central gland Greyed Orange N163B turning darker Brown N199B as they age. Herbarium specimen collected on 28/05/2015.



Euphorbia x pasteurii AGM (H6) 2015, (trial entries 93 & 94).

Sent by: Cotswold Garden Flowers, Browns' Nursery, Gibbs Lane, Offenham, Evesham, Worcestershire, WR11 8RR (nursery at Sands Lane, Badsey, Worcestershire, WR11 7EZ) AND Phoenix Perennial Plants, Paice Lane, Medstead, Nr Alton, Hampshire, GU34 5PR

Available


Description of entry 93: Habit: Robust, erect, spreading. Height x width (cm): 95 x 160. Foliage colour: Yellow green 144C bracts below inflorescence, leaves green 141A but yellower, mid-vein yellow green 145 B, under-surface green 148C but yellower, edge of upper surface red-purple 60B. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Yellow-green 145B flushed yellow orange 23D on opposite surface, younger growth with red purple blotting 60B. Flower colour: Perianth bracts small, insignificant, older Greyed Orange 165B, turning much darker (Brown N200A, but more orange), middle Orange N25A. Edged with hairy tufts. Herbarium specimen collected on 28/05/2015.

21 May 2015 21 May 2015 25 February 2015

Description of entry 94: Habit: Robust, erect to spreading shrub. Height x width (cm): 90 x 170. Foliage colour: Yellow Green 144A bracts below inflorescence, leaves Green 141A but yellower, mid-vein Yellow Green 145B, under-surface green Yellow Green 147D, edge of upper surface Greyed Purple 185B. Leaf pubescence and features: Glabrous, except scattered hairs on mid-vein of under surface. Stem colour, pubescence, etc.: Green Yellow 1C to Yellow Green 151D (younger part of the stem), maturing to Greyed Yellow 160A with Greyed Orange 174D, flushed Greyed Red 181B, glabrous. Flower colour: Perianth bracts small, insignificant, older Greyed Orange 165B, turning much darker (Brown N200A, but more orange). Edged with hairy tufts. Herbarium specimen collected on 28/05/2015.


21 May 2015 21 May 2015 25 February 2015

The following entries have been recommended for the AGM but cannot receive the award until they are available / naming issues have been resolved. It is the responsibility of the sender to inform the Trials Office at Wisley that all queries have been resolved.

Euphorbia nicaeensis (Right-hand plant only)

AGM (H5) 2015 SUBJECT TO AVAILABILITY AND BEING GIVEN A CLONAL NAME, (trial entry 11).


Forum comments: Lovely fresh foliage. Beautifully compact. Very healthy plants. July - the plant has taken on a pinkish hue and in combination with the blue foliage it is very pretty.

Description: Habit: Low, lightly upright to decumbent, spreading. Height x width (cm): 30 x 70. Foliage colour: Glaucous Greyed Green 189B, broad light Greyed Green 193A to Yellow Green 144C patch over mid rib from mid to base, especially prominent in inflorescence. Leaf pubescence and features: Dull, glabrous. Stem colour, pubescence, etc.: Green, yellower in inflorescence, lightly blushed Greyed Red 179C below, glabrous. Flower colour: Yellow Green 144A-B, glands similar but ageing to 153B. Flower features: Glands horned. Herbarium specimen collected on 16/05/2014.

17 June 2015 5 June 2015 23 February 2015


Euphorbia donii 'Amjillasa'

AGM (H6) 2015 SUBJECT TO A GROUP NAME BEING CONFIRMED, (trial entries 66 & 67).

Sent by: Great Dixter Nurseries, Dixter Road, Northiam, Rye, East Sussex, TN31 6PH

AND RBG Kew, Richmond, Surrey, TW9 3AB

Available

Forum comments: The new foliage is stunning, it has a wonderful red edge. Love the twist at the top of the rosette and the wide midrib. Lovely leaves and flowers. An absolute stunner.

Additional note: The Nepalese government maps and documents spell the name of the village as Amjilesa.

Description of entry 66: Habit: Upright to lightly spreading. Height x width (cm): 90 x 110. Foliage colour: Bright Mid Green, yellower than N137C and greener than 146B, finely edged Red 53A, mid rib white, tinged pink beneath; leaf under-surface much paler. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Pale lightly flushed pinkish 185D, glabrous. Flower colour: Involucre Yellow Green N144A with darker Green 143Bish patching, finely edged red, perianth bright Yellow Green 151B, glands 153A. Flower features: Strong cress smell. Herbarium specimen collected on 20/06/2014.

8 April 2015 21 May 2015 5 August 2015 26 June 2015

Description of entry 67: Habit: Fairly open habit, upright, fairly spreading, floriferous. Height x width (cm): 100 x 130. Foliage colour: Mid green, N137C to B, slightly yellow in younger leaves, pink-flushed at base 186B, especially beneath, paler and slightly glaucous beneath, paler 138B beneath, very fine red edge. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Pale lightly flushed pinkish 185A to 185D lower down, glabrous. Flower colour: Lower involucre Yellow Green N144A to 144A at darkest, perianth bracts of younger flowers Yellow Green 151A, glands 153A with touch of orange. Flower features: Cress smell. Herbarium specimen collected on 06/08/2014.

8 April 2015 21 May 2015 5 August 2015 5 August 2015


Euphorbia griffithii

AGM (H7) 2015 SUBJECT TO BEING GIVEN A CLONAL NAME, (trial entry 69).

Sent by: Galloway Plants, Claymoddie, Whithorn, Newton Stewart, DG8 8LX

Forum comments: Wow, fabulous, fantastic! Looks like a mini forest. Lovely flower colour. The red (flame colour) is the reddest of all the E. griffithii type entries in the trial.

Note: All E. griffitthii entries are prone to rust.

Description: To be completed in due course.

15 May 2014 15 May 2015 1 May 2015

Euphorbia stygiana Euphorbia stygiana 'Torridge'

AGM (H6) 2015 SUBJECT TO AVAILABILITY, (trial entry 86). This entry was named during the course of the trial.

Sent by: Mr J Armitage, c/o Trials Office, RHS Garden, Wisley, Woking, Surrey, GU23 6QB

Forum comments: Wonderful blunt tips to the leaves. Love the pale underside to the leaves. Very architectural plants. Looks like a piece of sculpture. Broader than it is tall. Lovely, chunky rosettes. Beautiful, amazing, fabulous! Known to reach around 1.8m (6ft) tall.

Description: To be completed in due course.

16 April 2015 5 June 2015 5 June 2015 25 February 2015


Euphorbia x pasteurii (PC Clone) Euphorbia x pasteurii ‘Honey Pot’

AGM (H6) 2015 SUBJECT TO AVAILABILITY, (trial entry 92). This entry was named at the end of the trial.

Sent by: Mr J Fielding, 27 East Sheen Avenue, London, SW14 8AR

Forum comments: Slightly different from the other entries of this type – more bushy, slightly smaller and foliage is slightly more yellow. A more compact habit. Branches more than the other entries. The red foliage and coral stems in winter (caused by the cold) can be very attractive.

Description: Habit: Erect to spreading robust shrub. Height x width (cm): 110 x 180. Foliage colour: Green 143A bracts below inflorescence, leaves Yellow Green 141A (but darker) above, mid-vein Yellow Green 145A above, Green 139C below. Leaf pubescence and features: Glabrous. Stem colour, pubescence, etc.: Yellow Green 149A (but darker) in younger stems, lightening to Yellow Green N144D with flush of Yellow 11C on opposite side, glabrous. Flower colour: Perianth bracts small, insignificant, older Yellow Green 152C, middle Greyed Orange 163A, younger Yellow Green N144A, edged with hairy tufts. Herbarium specimen collected on 28/05/2015.

21 May 2015 21 May 2015 25 February 2015

Reconfirmed AGMs:

Euphorbia myrsinites

AGM (H4) 1993 (trial entry 1).


Widely available

Forum comments: Lovely new growth. Good shape. Beautiful blue foliage.

30 March 2015 8 April 2015 1 May 2015 5 August 2015


Euphorbia rigida AGM (H6) 2004 (trial entry 3).

Sent by: Hardys Cottage Garden Plants, Priory Lane Nursery, Freefolk Priors, Whitchurch, Hants, RG28 7NJ

Available

Forum comments: More upright and has a more pointy leaf than E. myrsinites. Nice flush of pink on the new growth. Very contained and compact. A very structured plant.

25 February 2015 27 October 2015

Euphorbia cornigera AGM (H6) 2002 (trial entry 63).

Sent by: Crûg Farm Plants, Griffith's Crossing, Caernarfon, Gwynedd, LL55 1TU

Available

Forum comments: Fresh, vigorous, wonderful. Very impressive, bold flowers. Makes an architectural statement. Has a very good presence.

15 May 2015 5 August 2015


Euphorbia sikkimensis AGM (H5) 2002 (trial entry 77).

Sent by: The Beth Chatto Gardens, Elmstead Market, Colchester, Essex, CO7 7DB

Available

Forum comments: Fabulous, vibrant, glassy red shoots in spring. In July / August it has lime-green flowers which are very refreshing at that time of year. Nice foliage – carmine-red midrib with smoked red edges to the leaves and pink stems. Very consistent and even in height.

Clockwise from top left: 25 February 2015, 8 April 2015, 21 May 2015, 26 June 2015, 26 June 2015

Euphorbia palustris AGM (H7) 1993 (trial entry 81).

Sent by: Sampford Shrubs, Sampford Peverell, Tiverton, Devon EX16 7EN

Widely available

Forum comments: A cracking good garden plant. Compact, neat, upright habit. Nice, healthy foliage.

8 April 2015 1 May 2015 1 May 2015 5 August 2015


Rescinded AGMs:

Euphorbia characias 'Portuguese Velvet'

AGM (H7) 1998 (trial entries 12 & 45).

Reason for rescinding AGM: Considered to be variable and so can’t define the clone.

Euphorbia [Redwing] = 'Charam' (PBR)


Reason for rescinding AGM: Has been superceded. Suffers from mildew. Doesn’t persist in the garden.

Euphorbia characias [Silver Swan] = 'Wilcott' (PBR) (v)


Reason for rescinding AGM: Fine as seasonal bedding but not if used longer than that. Shapeless, wayward, not dome shaped. Not robust.

Euphorbia characias subsp. wulfenii 'John Tomlinson'


Reason for rescinding AGM: Didn’t see its potential as an AGM plant.

Euphorbia characias subsp. wulfenii 'Lambrook Gold'

AGM (H4) 1993 (trial entries 55 & 56).

Reason for rescinding AGM: Didn’t see its potential as an AGM plant. Used to be fantastic but have not seen any fantastic ones for 5-6 years.

Euphorbia griffithii 'Dixter'


Reason for rescinding AGM: Has quite good bronze, summer foliage but has gone downhill and been superseded.


Trial Index and Sender Details

Planting number

Name Sender

1 Euphorbia myrsinites AGM (H4) 1993 Phoenix Perennial Plants

2 Euphorbia cyparissias 'Fens Ruby' The Beth Chatto Gardens

3 Euphorbia rigida AGM (H6) 2004 Hardys Cottage Garden Plants

4 Euphorbia 'Abbey Dore' Phoenix Perennial Plants

5 Euphorbia deflexa Beeches Nursery

6 Euphorbia pithyusa The Beth Chatto Gardens & replacement plant from Cotswold Garden Flowers

7 Euphorbia 'Copton Ash' Kevin Hughes Plants

8 Euphorbia 'Blue Haze' Cotswold Garden Flowers

9 Euphorbia seguieriana The Beth Chatto Gardens

10 Euphorbia seguieriana subsp. niciciana Hoo House Nursery

11 Euphorbia nicaeensis Phoenix Perennial Plants

12 Euphorbia characias 'Portuguese Velvet' AGM (H7) 1998

J Fielding

13 Euphorbia nicaeensis subsp. glareosa var. lasiocarpa

University of Oxford Botanic Garden

14 Euphorbia epithymoides (formerly Euphorbia polychroma)

National Collection of Euphorbias

15 Euphorbia epithymoides 'Bonfire' (PBR) (formerly Euphorbia polychroma 'Bonfire' (PBR))

Bridgemere Garden Centre & replacement plant from Avondale Nursery

16 Euphorbia epithymoides 'Senior' (formerly Euphorbia polychroma 'Senior')

Walberton Nursery via Farplants

17 Euphorbia fragifera University of Oxford Botanic Garden

18 Euphorbia epithymoides 'Candy' (formerly Euphorbia polychroma 'Candy')

The Beth Chatto Gardens

19 Euphorbia epithymoides 'Midas' (formerly Euphorbia polychroma 'Midas')

National Collection of Euphorbias

20 Euphorbia epithymoides 'Major' AGM (H6) 1996 (formerly Euphorbia polychroma 'Major' AGM (H6) 1996)

Great Dixter Nurseries

21 Euphorbia amygdaloides var. robbiae Walberton Nursery via Farplants

22 Euphorbia amygdaloides 'Purpurea' Hillier Nurseries Ltd Three replacement plants from RHS Garden Wisley

23 Euphorbia amygdaloides 'Craigieburn' Dove Cottage Nursery

24 Euphorbia amygdaloides 'Frosted Flame' (PBR)


25 Euphorbia [Blackbird] Nothowlee (PBR) Avondale Nursery & replacement plants from Cotswold Garden Flowers


Planting number

Name Sender

26 Euphorbia 'Despina' (PBR) Bodiam Nursery

27 Euphorbia 'Efanthia' (PBR) Hillier Nurseries Ltd

28 Euphorbia [Redwing] = 'Charam' (PBR)

AGM (H5) 2002 Avondale Nursery

29 Euphorbia [Kalipso] = 'Imprkalip' RHS Garden Wisley

30 Euphorbia 'Whistleberry Garnet' Rijnbeek & Son Perennials via Ronald Houtman

31 Euphorbia x martini 'Baby Charm' Hillier Nurseries Ltd

32 Euphorbia x martini 'Kolibri' Beeches Nursery

33 Euphorbia x martini ['Tiny Tim'] 'Waleutiny' Walberton Nursery via Farplants

34 Euphorbia x martini [Rudolph]

'Waleuphrud'


35 Euphorbia x martini 'Walberton's Red Flush'


36 Euphorbia x martini 'Helen Robinson' Cotswold Garden Flowers

37 Euphorbia x martini Madrona Nursery

38 Euphorbia x martini 'Ascot Rainbow' Madrona Nursery

39 Euphorbia characias 'Tasmanian Tiger' (PBR) (v)

Cotswold Garden Flowers

40 Euphorbia characias 'Kestrel' (v) Cotswold Garden Flowers

41 Euphorbia characias subsp. wulfenii 'Emmer Green' (v)


42 Euphorbia characias [Silver Swan] =

'Wilcott' (PBR) (v) AGM (H2) 2012


43 Euphorbia characias 'Glacier Blue'

Walberton Nursery via Farplants Three replacement plants from RHS Garden Wisley

44 Euphorbia characias 'Dwarf Black Pearl' Worlds End Garden Nursery

45 Euphorbia characias 'Portuguese Velvet' AGM (H7) 1998

2 plants from The Beth Chatto Gardens & 1 from RHS Garden Wisley Three replacement plants from Cotswold Garden Flowers

46 Euphorbia characias subsp. wulfenii ‘Shorty’

Plantipp BV via Ronald Houtman

47 Euphorbia characias subsp. wulfenii 'Silver Shadow'


48 Euphorbia characias 'Blue Wonder'

Avondale Nursery Three replacement plants from Cotswold Garden Flowers

49 Euphorbia characias 'Black Pearl' Walberton Nursery via Farplants

50 Euphorbia characias 'Forescate' Beeches Nursery


Planting number

Name Sender

51 Euphorbia characias subsp. characias 'Blue Hills'

Worlds End Garden Nursery

52 Euphorbia characias subsp. characias 'Humpty Dumpty'


53 Euphorbia characias subsp. wulfenii 'Jimmy Platt'


54 Euphorbia characias subsp. wulfenii 'John Tomlinson' AGM (H4) 1993

RHS Garden Wisley Three replacement plants from Spring Reach Nursery

55 Euphorbia characias subsp. wulfenii 'Lambrook Gold' AGM (H4) 1993


56 Euphorbia characias subsp. wulfenii 'Lambrook Gold' AGM (H4) 1993

Sampford Shrubs

57 Euphorbia characias subsp. wulfenii 'Purple and Gold'

Worlds End Garden Nursery

58 Euphorbia characias subsp. wulfenii Hillier Nurseries Ltd

59 Euphorbia characias subsp. wulfenii 'Thelma's Giant'

Avondale Nursery

60 Euphorbia oblongata Cotswold Garden Flowers

61 Euphorbia wallichii ambig. Phoenix Perennial Plants

62 Euphorbia jacquemontii Cotswold Garden Flowers

63 Euphorbia cornigera AGM (H6) 2002 Crûg Farm Plants

64 Euphorbia cornigera 'Goldener Turm' Cotswold Garden Flowers

65 Euphorbia [Excalibur] = 'Froeup' (PBR) The Beth Chatto Gardens

66 Euphorbia donii 'Amjillasa' Great Dixter Nurseries

67 Euphorbia donii 'Amjillasa' RBG Kew

68 Euphorbia donii Great Dixter Nurseries

69 Euphorbia griffithii Galloway Plants

70 Euphorbia griffithii 'Dixter' AGM (H7) 1993 Great Dixter Nurseries

71 Euphorbia griffithii 'Fern Cottage' Elworthy Cottage Plants

72 Euphorbia griffithii 'Wickstead' Longstone Hardy Plant Nursery

73 Euphorbia griffithii 'King's Caple' Crûg Farm Plants

74 Euphorbia griffithii 'Fireglow' The Beth Chatto Gardens

75 Euphorbia margalidiana National Collection of Euphorbias

76 Euphorbia schillingii AGM (H5) 1993 Spring Reach Nursery Ltd

77 Euphorbia sikkimensis AGM (H5) 2002 The Beth Chatto Gardens

78 Euphorbia sikkimensis 'Crûg Contrast' Crûg Farm Plants

79 Euphorbia valdevillosocarpa Phoenix Perennial Plants

80 Euphorbia palustris 'Walenburg's Glorie' The Beth Chatto Gardens

81 Euphorbia palustris AGM (H7) 1993 Sampford Shrubs

82 Euphorbia ceratocarpa National Collection of Euphorbias

83 Euphorbia sarawschanica Phoenix Perennial Plants


Planting number

Name Sender

84 Euphorbia nereidum University of Oxford Botanic Garden

85 Euphorbia mellifera AGM (H2) 2002 Great Dixter Nurseries

86 Euphorbia stygiana named Euphorbia stygiana 'Torridge'

J Armitage

86 B Euphorbia stygiana subsp. santamariae J Fielding

87 Euphorbia stygiana Sampford Shrubs

88 Euphorbia stygiana Special Plants

89 Euphorbia 'Roundway Titan' Brockhill Nurseries

90 Euphorbia x pasteurii 'Phrampton Phatty' RHS Garden Wisley

91 Euphorbia x pasteurii 'John Phillips' RHS Garden Wisley

92

Euphorbia x pasteurii (PC Clone) (also sometimes called Euphorbia stygiana hybrid or Euphorbia stygiana x mellifera) named Euphorbia x pasteurii ‘Honey Pot’

J Fielding

93 Euphorbia x pasteurii (also sometimes called Euphorbia stygiana hybrid or Euphorbia stygiana x mellifera)


94 Euphorbia x pasteurii (also sometimes called Euphorbia stygiana hybrid or Euphorbia stygiana x mellifera)

Phoenix Perennial Plants

Sender Details: Mr J Armitage, c/o Trials Office, RHS Garden, Wisley, Woking, Surrey, GU23 6QB Avondale Nursery, 3 Avondale Road, Coventry, West Midlands, CV5 6DZ Beeches Nursery, Village Centre, Ashdon, Saffron Walden, Essex, CB10 2HB The Beth Chatto Gardens, Elmstead Market, Colchester, Essex, CO7 7DB Bodiam Nursery, Bodiam, Newr Robertsbridge, East Sussex, TN32 5RA Bridgemere Nurseries Ltd, nr. Nantwich, Cheshire, CW5 7QB Brockhill Nursery, Sway Road, Tiptoe, Lymington, Hampshire, SO41 6FR Cotswold Garden Flowers, Browns' Nursery, Gibbs Lane, Offenham, Evesham, Worcestershire, WR11 8RR -nursery at Sands Lane, Badsey, Worcestershire, WR11 7EZ Crûg Farm Plants, Griffith's Crossing, Caernarfon, Gwynedd, LL55 1TU Dove Cottage Nursery, Shibden Hall Road, Halifax, West Yorkshire, HX3 9XA Elworthy Cottage Plants, Elworthy Cottage, Elworthy, Taunton, Somerset, TA4 3PX Mr J Fielding, 27 East Sheen Avenue, London, SW14 8AR Galloway Plants, Claymoddie, Whithorn, Newton Stewart, DG8 8LX Great Dixter Nurseries, Dixter Road, Northiam, Rye, East Sussex, TN31 6PH Hardys Cottage Garden Plants, Priory Lane Nursery, Freefolk Priors, Whitchurch, Hants, RG28 7NJ Hillier Nurseries Ltd, Ampfield House, AMpfield, Romsey, Hampshire, SO51 9PA Hoo House Nursery, Hoo House, Gloucester Road, Tewkesbury, Glos., GL20 7DA Kevin Hughes Plants, c/o Trials Office, RHS Garden, Wisley, Woking, Surrey, GU23 6QB Longstone Hardy Plant Nursery, Station Road, Great Longstone, Near Bakewell, Derbyshire, DE45 1TS Madrona Nursery, Pluckley Road, Bethersden, Kent, TN26 3DD National Collection of Euphorbias, 26 Casson Drive, Harthill, Sheffield, S26 7WA


Phoenix Perennial Plants, Paice Lane, Medstead, Nr Alton, Hampshire, GU34 5PR Plantipp BV, c/o Trials Office, RHS Garden, Wisley, Woking, Surrey, GU23 6QB RBG Kew, Richmond, Surrey, TW9 3AB RHS Garden, Wisley, Woking, Surrey, GU23 6QB Rijnbeek & Son Perennials, c/o Trials Office, RHS Garden, Wisley, Woking, Surrey, GU23 6QB Sampford Shrubs, Sampford Peverell, Tiverton, Devon EX16 7EN Special Plants, Greenways Lane, Cold Ashton, Chippenham, Wiltshire, SN14 8LA Spring Reach Nursery Ltd, Longreach, Ockham, Surrey, GU23 6PG University of Oxford Botanic Garden, Rose Lane, Oxford, OX1 4AZ Walberton Nursery, Yapton Lane, Arundel, BN18 0AS Worlds End Garden Nursery, Moseley Road, Hallow, Worcester, WR2 6NJ

Source: Horticultural Trials and Relations, RHS Garden Wisley, Woking, Surrey GU23 6QB

E-mail: [email protected]

More information about RHS Trials and other colour illustrated reports can be found on the RHS Website: http://www.rhs.org.uk/trials

mailto:[email protected]

http://www.rhs.org.uk/trials

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