Page 15 - Simply Vegetables Winter 2022/23

Carrot fly protection
Crop protection
growers be doing to grow their vegetables, firstly they should be composting any organic material available including if possible, shredding any pruning’s to mix into the heap. Build a compost bin or two if space and compost all green waste and any material you can get from neighbours or friends. You will never have too much compost and apply as much as you have available either as a mulch or dig into the soil.
The next point is to sow green manure plants on any spare and vacant ground and leave for as long as possible before either composting or digging in. Green manuring is well worth doing and will improve the soil fertility and feed the soil and soil fauna.
Staying on the organic matter theme
try to obtain as much organic materials as possible from any source available. The type of materials includes animal manures (unless a vegan grower), spent hops, and spent mushroom compost, municipal composted green waste, worm compost, leaf mould, bark and woodchip. Check they have not been treated with any chemicals that could affect your plants, especially
the feedstocks to any animals. If they are fresh most of these materials will need composting, so stack in a heap and cover to retain the heat and prevent any leaching of nutrients.
Looking at organic growing any problems like weeds, pests and diseases need to be dealt with using organic methods like cultural controls or natural methods rather than chemicals. Starting
with weeds these can be controlled or prevented using organic mulches which cover the soil and prevent or at least reduce the number of weeds that germinate and grow. Mulching is very useful on perennial crops like rhubarb, asparagus, artichokes etc. and most fruits. Once spread or laid over the surface little weeding is required. Other cultural methods of weed control include regular hoeing which is remarkably effective if done at regular intervals. I can hoe my allotment in a morning and then watch my fellow allotmenteers spend
hours forking over small patches to remove weeds. If hoed at 10 to14 day intervals, it will control most weeds and the odd perennial weed that occurs can be forked out or removed with a trowel. If taking over a new weedy area either strim down the weeds and cover with cardboard or black plastic or scrape them off and compost them if
not full of roots. Either fork over the area to prepare for planting or plant straight through the mulch.
Moving onto pest problems the main organic method of control is prevention, that is to prevent the pest reaching the crop. This can be done by covering with fleece, fine netting, or polythene and this will prevent most flying pests getting to the crop to feed on or lay their eggs. Collars can by placed around Brassica plants to prevent the cabbage root fly laying eggs. When buying your seeds have a look for any that are resistant to pests and diseases especially if you have a problem with one. It can be worth having trawl through the seed catalogues or company websites to see what is available. For cucumbers and tomatoes as well as some top fruit grafting onto a rootstock can give resistance to certain pests or diseases.
Another method is to make use of predators like ladybirds, lacewings, hoverflies, as well as hedgehogs, frogs, toads, slow worms, birds and others. These need to be encouraged into the garden
by providing habitats for them to take
up residence and a food source. Organic growers tend to be more relaxed about a small amount of damage to crops although they are unlikely to be top exhibitors!!
Timing the sowing to miss the active
part of the pest’s life cycle can often avoid bad attacks and works with carrot fly and some other pests. Also knowing when the adults are becoming active can help in controlling them so when the cow parsley in the verges is coming into flower the adult carrot fly is starting to fly.
Soil pests not controlled by predators can sometimes be controlled using biological controls like the many species of nematodes which can be used to control cutworms, chafer grubs, leatherjackets, wireworms, and slugs. Although expensive they work and give good control, but slugs may need a second treatment. There are microbial substance becoming available now, again like predators they can be expensive, but work and they use naturally occurring bacteria or similar organisms. Currently the most commonly used are Bacillus subtilis, Bacillus thuringiensis and
Pheromone trap SWD
Simply Vegetables 15