Saintbridge Allotment Gardens Association

Transcription

1 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

2 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.

3 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.

4 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.

5 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 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. IF YOU HAVE ANYTHING YOU WOULD LIKE TO CONTRIBUTE TO NEXT MONTHS NEWSLETTER PLEASE CONTACT SAGA SECRETARY