If you’re new to organic gardening you may think that being organic means extra physical work and swapping your conventional sprays for organic ones. But really it only requires a greater use of your mental faculties. When it comes to organic gardening prevention is better than cure.
Healthy growth depends on a healthy soil. Too much fertiliser and your plants will be soft and sappy. The result will be a lovely lunch for the pests and the need for you to spray. Feed your soil with a wholefood diet of garden compost and leafmould rather than using the fast-food artificial fertilisers that are designed to feed only the plant. Feeding the soil rather than the plant will mean stronger growth and better resistance to pests and diseases. Research has already proved this to be true.
Healthy plants depend on it. For organic gardeners there is also another very important tool in preventing pests and diseases, this is choosing varieties that have been bred for their pest and disease resistance. For example, blight resistant potatoes such as ‘Remarka‘ and ‘Sarpo‘, and root aphid resistant lettuces such as ‘Milan‘.
Focusing for a moment on your vegetable garden, there is one essential pest and disease control that you must practice – crop rotation. This involves dividing your vegetables into at least four groups that stay together each year but move onto the next part of the rotation every spring. The vegetables are grouped by family as well as similar feeding habits. Apart from being the best way to build soil fertility, it is the most important factor in controlling the build-up of pests and diseases. All organic growers practice crop rotation.
Barriers are the best way of reducing pest damage. By covering your vegetables with a fine mesh you will stop them being attacked by flying pests. This works well for carrot rootfly and pea moth. Fine mesh is also an all inclusive way of protecting your cabbages from just about everything including flea beetles, leaf weevils, birds, cabbage white butterflies and white fly.
Other barriers include cabbage collars and bottle cloches. Placing a collar of carpet underlay around the neck of a young cabbage will prevent the cabbage root fly from laying its eggs at the base of the cabbage.
Placing a bottle cloche (a clear plastic bottle with the top and bottom removed) over newly planted vegetables will prevent them being eaten by slugs or anything else that takes a fancy to them.
Small gauge chickenwire is always useful. Placing it over your newly sown peas can stop them being eaten by mice while they are germinating or being scratched up by cats. Wrap it around your flowering bulbs to prevent squirrels from digging them up.
Netting can also be very useful at preventing bird damage to fruit and vegetables. There is also a humming line that can be wound around canes criss-crossed over your vegetables to prevent bird attacks. Netting can also prevent cabbage white butterflies from laying their eggs on your brassicas.
Barriers can also be used to prevent diseases. For example, peach leaf curl is a devastating fungus that can simply be prevented by placing a barrier of polythene sheeting over a trained peach tree in the winter. This simple barrier prevents the spores splashing up onto the plant.
Another popular method of protecting your plants is to use traps. This can be anything from beer traps for slugs (and yes, they really do work!) to codling moth traps hung from your apple trees. Sticky traps are very popular with the organic gardener.
A codling moth trap, for example, uses a pheromone placed on a sticky floor. The male moth is attracted to the trap thinking it is a female. On landing he gets stuck in the glue. There are similar traps for plum moths, too.
Beneficial insects and wildlife are really your best friends when it comes to controlling pests in your garden and vegetable patch. Planting simple annuals amongst your vegetables, such as Californian poppies and marigolds will attract a wealth of beneficial insects like ladybirds and hoverflies who will gobble up your aphids. Plant a few native shrubs and herbaceous perennials (ie hazel and hardy geraniums) in your garden; create a pond; leave a small pile of logs in the corner of your garden.
The final thing to remember when trying to control pests and diseases in an organic garden is hygiene.
If trying to remove a diseased branch from a tree, coral spot for example, cut into healthy wood and always wash your tools in boiling water afterwards.
Always scrub out your pots and give your greenhouse a good scrub every winter to get rid of those over-wintering pests.
Maximising air circulation by correct pruning and leaving just a little more space between your plants can help control fungal diseases, for example powdery mildew in roses.
Finally and most importantly, check your plants regularly so that any pest and diseases don’t get a chance to get a hold. For example, if you start checking the centre of your gooseberry bushes in April for sawfly eggs and larvae you can remove them and therefore prevent them from defoliating your crop. Also be wary of accepting onion and cabbage plants from a friendly neighbour, they may well carry the dreadful diseases of onion white rot and clubroot. You will never be able to get rid of these diseases so err on the side of caution and ‘just say no’. If you have an allotment with either of these diseases then don’t even use the same tools or boots in your own garden because you will spread them.
So to all the beginners who thought they were just going to do a straight swap from conventional to organic gardening by simply changing their sprays it is not quite so simple. Organic gardening is the thinking man/woman’s horticulture. Planning, forethought, observation and vigilance make for success in the organic garden and remember, prevention is better than cure!