Download March - Saintbridge Allotments

Saintbridge Allotment Gardens Association
March 2016 Newsletter
March sees the start of planting and sowing on the allotment; shallots, broad beans and hardy
varieties of peas can all be planted early in the month if soil conditions are dry enough. Also aim to
plant first early potatoes and onion sets in March.
You can sow spring onions, radish, early turnips, lettuce, beetroot (variety bolthardy), leeks, parsnips
and spinach beet. Later in the month you can plant out the first batch of brassica transplants
(summer cabbage and broccoli). Using cloches will benefit these early sowings and plantings
particularly in a cold spring.
If you have a cold frame or greenhouse to raise young plants you can sow tomatoes and peppers in a
window sill propagator, to be potted on, and transplanted out later in the year. Cucumbers and
pumpkins can also be started off this way at the end of March/early April. Alternatively, these plants
can be bought from most garden centres later in the year.
To keep ahead of work on the plot, aim to complete any winter digging and general preparations
before the main block of planting and weeding in April and May.
Beneficial insects
Very few of the many types of insects found on crops are actually pests, the vast majority do no
harm and some are beneficial. This section looks at ways to improve natural pest control by
attracting beneficial insects of which there are three main types; pollinators, predators and
parasitoids. Pollinators include the many types of bumble bee, honey bees and some butterflies and
moths. These insects perform the vital role of pollinating crops.
Important predators are ladybirds, hoverflies, lacewings, ground beetles, spiders, beneficial mites
and dragonflies. All these insects prey on the harmful insects. Ground beetles are particularly helpful
as they will eat very young slugs, caterpillars and grubs. Frogs, toads and hedgehogs are also
important predators of slugs and snails. Aphids (blackfly and greenfly), whitefly, thrips, spider mites,
and other sap sucking insects are eaten by ladybirds, hoverflies and lacewings. Lacewing larvae also
feed on caterpillars. Spiders and dragonflies will eat anything they can catch and they may help to
keep the numbers of pests and predators in balance.
Adult Lacewing
Lacewing larva
Adult Ladybird
Ladybird larva
Adult Hoverfly
Hoverfly larva
Ground beetle
Among the parasitoids there are many small parasitic wasps, these lay their eggs on or inside the
harmful insects and when the eggs hatch the larvae eat the pest. They eat whiteflies, moth, beetle
and fly larvae. Similarly there are many types of Tachinid fly (they can look like house flies) and they
control harmful insects in the same way. They can eat caterpillars, beetle and fly larvae. Parasitic
nematodes marketed under the trade name Nemaslug can also be used to control slugs.
Parasitic wasp
Tachinid fly
Creating a home for wildlife
It is good practise to devote around 5% of a piece of ground to provide food, water and a home for
wildlife. Applied on a larger scale this is often called Farmscaping, where areas of less productive
land, awkward to work corners and boundary areas are developed for wildlife. Usually the types of
plants grown are selected to provide more than one function (wind breaks, shade for livestock etc.).
Examples of this kind of development at the Saintbridge Allotment site include.
Hazel coppice
Situated in an area unsuitable for allotment plots the hazel coppice provides a woodland habitat for
wildlife. The hazel will be coppiced on a rotation to produce bean poles and pea sticks for sale to
plotholders . The understory is planted with native bulbs to give pollen and nectar for insects. As the
area is a secluded spot it houses bee hives managed by a professional bee keeper. The bees pollinate
our crops and produce honey.
Hedgerows
The mixed native species hedgerows planted around the site are a living fence improving security at
the site. They also provide flowers, fruit and nest sites for wildlife and give a wind break. The
deadwood from hedge trimmings and leaf litter in the bottom of the hedgerow provides
overwintering sites for many beneficial insects.
Wild flower meadow
The wild flower meadow is an attractive feature planted on a strip of ground too narrow for an
allotment plot. The meadow supports a range of beneficial insects that can spread out each year to
eat pests on allotment plots. The meadow is cut once or twice a year and the vegetation removed to
make compost. This is necessary to maintain the low soil fertility needed by the meadow flowers.
Insectary garden
At a smaller scale there are many things individual plotholders can do to encourage beneficial
insects. Setting aside six square meters is all you need to establish a small insectary garden. The aim
is to create a range of different habitats to encourage the different beneficial insects. As the garden
matures it becomes a base camp from which the beneficial insects can breed, multiply and munch
their way through the pests on your plot.
An example of an insectary garden
Start by preparing the ground making sure it is free of any perennial weeds. On plots with heavier
clay soil, dig the soil to create a raised bank with slopping sides running into a furrow on one side of
the bank. Ideally the bank should be three or four foot wide at the base and one foot high at the
centre of the bank. This will give a range of soil conditions from damp conditions in the furrow
bottom to dry well drained conditions on top of the bank. It is not necessary to create this kind of
raised bank on the lighter free draining soils on the allotment site, predominately found on plots 1 to
19 and plots 50 to 62.
For most of the beneficial insects it is the larvae that eat the pests while the adults need to feed on
pollen and nectar from small single flowers. Because of this plants from the Umbelliferae (carrot
family), Compositae (daisy family) and Lamiaceae (mint family) make good insectary plants. Choose
six or more plants (see list below) that give a range of heights. Include some ground cover plants to
give habitat for ground beetles, frogs, toads and spiders and some tall plants to add structure and
give resting places for dragonflies and butterflies. Also include plants that will flower at different
times of the year to give a continuous supply of pollen and nectar.
The following list is not intended to be comprehensive but it suggests some useful insectary plants
many of which have a dual function.
Pot marigold A hardy annual, will self-seed freely so dead head the flowers. The plant flowers from
May to the first frosts of autumn. Direct sow in spring or early summer, will tolerate light shade.
Common Tansy A perennial herbaceous plant, likes well drained soil and full sun. Flowers July
August. Dead head the flowers to prevent seeding, the plant can cause allergic skin reactions so
wear gloves when handling.
Ox eyed daisy A low maintenance perennial, flowers May to July. Sow seed in autumn or spring, the
plant starts flowering from the second year onwards.
Shasta daisy, A low maintenance perennial that flowers from June to November. It needs well
drained soil and can tolerate partial shade. If grown from seed the plant starts flowering from the
second year onwards.
Cosmos A tender annual, sow under glass in March/April and plant out after the last frosts. Likes full
sun and flowers late summer and autumn.
Lemon balm A perennial mint that does not spread aggressively like other mints. Likes well drained
soil and some shade. The plant flowers June to November. If you want to plant other mints that
spread vigorously from their roots plant them inside a large flower tube or old bucket with holes in
the bottom. This will contain the roots and stop them spreading. The container can be buried in the
ground if desired.
English Lavender A perennial herb very attractive to bees and butterflies, likes well drained soils and
full sun. It is easily propagated from cuttings taken in August. Flowers May to July.
Rosemary A perennial herb that is easily propagated from cuttings, needs well drained soil. Flowers
April to June and often flowers again in the autumn. Prune back after flowering in June to encourage
new growth.
Borage An annual herb very attractive to bees and butterflies, self seeds readily so dead head the
flowers, can be grown in full sun or partial shade in a wide range of soil conditions. The plant flowers
from June to September.
Dill An easy to grow annual herb, succession sow seeds directly in the ground. To attract insects
allow some plants to flower. The plant flowers about 8 or 9 weeks after sowing.
Yarrow A hardy perennial that flowers June to August. Direct sow the seed in spring or autumn and
deadhead the flowers to prevent excessive seeding.
Parsnip A well known root vegetable, being a biannual it flowers in the second year. You can leave
one or two plants to flower in situ or dig up the root in February or March and plant it in the
insectary garden or elsewhere on your plot. It will flower using the food reserves in its root.
Parsley A biannual herb, likes moist, fertile soil. Give the plant some protection overwinter and it will
flower the following year.
When planting, put plants that need well drained conditions on top of the bank and add a couple of
handfuls of gravel or small stones in the bottom of the planting hole to improve drainage. Put plants
that like moist conditions in the bottom of the furrow. You could also plant some insectary plants
interspersed between your vegetables or have them in flower tubes and move them around as
required.
Provide drinking water in the insectary garden by adding a bird bath or shallow dish filled with
water. Create shelter for ground dwelling insects, frogs and toads by adding a layer of bark mulch
and a few piles of stones and dead twigs.
If you are able to, adding a small pond will greatly increase the types of wildlife visiting the garden
and it gives a breeding site for frogs, toads and dragonflies. It’s a good idea to cover the pond with
weld mesh to prevent young children falling in. Put in some hibernation sites for bumblebees and
lacewings, for more information on this please see
http://www.merseyforest.org.uk/howtoguides/hibernationandnesting.pdf
Finally, learn to tolerate a few pests on your crops, particularly when you can see the beneficial
insects as well. Where possible use nonchemical control methods such as netting to keep brassica
plants free of caterpillars and cabbage collars to control cabbage root fly. That way your vegetables
will grow organically and you will not risk eating potentially harmful chemicals. Only use pesticides
when your crops have large numbers of pests on them and then only use ones with a short residual
effect.
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