grow your own, nevada! spring 2012: raised bed gardening
TRANSCRIPT
Angela O’Callaghan, PhD
Social Horticulture Specialist
University of Nevada
Cooperative Extension
2/25/2013 2
Different definitions:
• Area of amended soil slightly
higher than surroundings
• Discrete structure containing
varied kinds of fill
Can be built to size, height
and mobility needs of gardener
Can be made of
brick, block, wood,
plastic, etc.
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• Plastic can
look like
almost
anything,
including
wood
• Control over plants’ environment:
–Fill, water, fertility management
• Varied bed height for convenience
• Few weed problems
• Discrete size, easier to work
• Smaller area to shade or protect from frost, when necessary
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• Can be
temporary or
permanent
• Must be filled
with fertile,
well-drained
mix
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May be:
•Unglazed clay (terra
cotta)
•Glazed clay
•Plastic
•Wood
•Biodegradable material
•Large
•Small
•Sitting
•Hanging 2/25/2013 14
Plastic –
Can look like almost any material
Holds water well
Low cost
Wood
Good drainage
Rustic appearance
Can be expensive
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• How much $$ do you want to
spend?
• How much space can you dedicate
to it
• How convenient will it be
• Who will build it
• http://www.cleanairgardening.com
/raised-bed-gardening.html
• Lumber ~ $1/linear foot
– Walls & uprights
– 2” x 10” x length of choice x height of choice
– 4” x 4” x height of choice
– May need more uprights for long, tall bed
• Hardware ~ $5 per upright
• A 20” high, 10’ long, 4’ wide bed ≈ $125
• ~ $1 per
• ~ 2” x 2” x 8”
• Need ~ 420 bricks for
–10’ long x 4’ wide x 20” high
• Mortar (2) ~ $20
• Cost ≈ $440
• Bed = 10’ long x 4’ wide x 18” high
• ~ $1.50/block (16” x 6” x 6”)
• ~ 68 blocks ~ $102
• Mortar 2 bags ~ $20
• ≈ $142
• Very wide price range
• May mimic wood or block
• Does not survive Nevada conditions
• Potting mix
• “Planter mix”
• Potting soil
• Other
• Peat moss, perlite, vermiculite, soluble fertilizer
• Chipped wood, composted manure
• Field soil, peat moss, perlite
• Varying amounts of organic matter in a matrix
• Potting mix
• “Planter mix”
• Potting soil
• Other
• Expensive, dries out quickly
• Materials may not be fully
composted, could burn roots
• May contain seedling pathogens
• Varying problems, poor water
holding, incomplete composting,
fertility may be questionable
• A raised bed is a confined space
• It makes sense to plant annuals (or
plants that we treat as annuals)
• We treat most of the vegetables
we grow as annuals, whether they
are or not
• Many of our common vegetables
are not
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• Vegetables are often grown as annuals,
although they may technically be something
else
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• Lettuce
• Spinach (not New Zealand or Malabar
spinach)
• Chard
Usually only want the
first years growth –
leaves, roots, stalks;
second year it
flowers
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Flowering broccoliFlowering carrots
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• Artichokes
• Jerusalem artichokes
• Sweet potatoes
• Tomatoes
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• Annuals will flower and produce seeds once
before dying
• Biennials will flower and produce seeds once,
and only if they have experienced a chilling
period with short days
• The desired part of many biennial vegetables
is produced only in the first year
• Perennials can produce for several years
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Express the gardener’s
taste
Sophisticated
Rustic
Urban
Antique
Eclectic
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A pot is a miniature garden plot
As long as there is sufficient room
for roots and drainage, it can
work
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Such as condensed
foam
• Can look like
decorative clay without
the weight or cost
• Can be thicker-walled
than plastic for better
insulation402/25/2013
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• Insulation
• Conserves water
• Moderates heat
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Material
• Brick
• Block
• Wood
• Plastic
Problem
• Expensive, may need
mortar
• May release salt
• Expensive, may not
withstand extreme
weather
• Expensive, will not
withstand extreme
weather
• From P. Allen Smith’s website
•Certain vegetables grow smaller if
planted close together
•This technique is best for leafy
vegetables
•Less for fruiting vegetables
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• Most herbs are grown either for leaves
(basil, oregano, mint) or flowers (dill)
• Many can grow as companion plants
• May be used as houseplants
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• Herbs can be
somewhat crowded
as long as there is
sufficient air
circulation
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Even if you have a large
space
Grow
aggressive
plants in pots
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• Each plant removes available
nutrients that it needs
• In a confined area like a raised bed
the soil or mix may become
depleted
• These need to be replaced
• Native desert soils are generally infertile
• Soils placed around construction are generally worse
• Gardeners need to increase fertility
• Soluble fertilizers are commonly used– May be organic or conventional
– Very convenient
– Concentrated levels of nutrients (conventional)
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• Commercial all-purpose fertilizers
have nitrogen, phosphorus and
potassium
• The % of each (in that order, always)
is listed on the package
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• In addition to NPK, several other micronutrients may be present in product.
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If you want to grow
organically, then
conventional
fertilizers are a no-no
If you want what is
usually most
convenient, then
organic methods
might be too much of
a bother
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Irrigation, hose, watering can
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• Ongoing fresh crop of plants
• Some plants are only used fresh
• For instance, leafy greens
• For continual supply, calculate:
– time from planting to mature plant
– amount that is planted at any one time
– How long plant(s) will stay usable
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• How long from seed to mature
plant?
• How long will a first crop last?
• How much of a variety does the
gardener (and family) eat?
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• Have salad green that takes 45 days from
seeding to maturity at 60 (early spring)
– Plant on February 1
– Plants mature about March 18, but can begin
eating on March 13
– If one planting yields 14 salad days, by March
27, first crop is finished.
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• Want to have continuous salad
• Need new crop by March 27
• At 75 plants grow faster, say 42 days to
maturity
• Count backwards six weeks from Mar 27
• Begin planting by February 13
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• Plant earlier in spring
• Grow later in fall
• Grow longer despite seasonal
changes
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• Right plant, right place
• Properly fertilized
• Properly watered
• Receives enough light
• Sheltered from excess light, wind, heat,
cold
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• Mulch
• Wall o’Water
• Floating row covers
• Cloches
• Shade cloth
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• Straw
• Pine needles
• Shredded
wood