Features
What Do Organic Growers Do About Aphids?
Aphids are common summer pests. Their sucking action causes severe damage, particularly to young plants. Lush, overfed growth holds a special attraction for them. Established healthy plants can frequently withstand severe attacks but seedlings can be seriously stunted.
Mould and Viruses
Honeydew is the attractive name given to the messy black substance exuded by aphids. It's easy enough to wipe off tomatoes but on soft fruit such as strawberries it's impossible to remove without damaging the fruit. Left on plants, it can encourage a sooty mould which will inflict further damage.
Aphids carry many incurable viral diseases.' June yellows' on strawberries is one example. Happily aphids are fairly easy to get rid of as even a heavy shower can reduce their numbers. It follows therefore that simply throwing a bucket of water on your plants will destroy many of them.
Predators
Aphids have many predators the best known of which is the ladybird. In a normal year, whatever that is, ladybirds should keep the population under control. Unfortunately many ladybirds starve in late spring if there is little to sustain them and the surviving population is often too small to deal with the rapidly multiplying pests. One source of ladybird food in spring is the nettle aphid. So don't remove all your nettles.
Although its larva destroys more, the adult ladybird can only eat five greenfly per day. This compares unfavorably with the hoverfly which has a capacity for up to fifty. Poached egg plants will encourage hoverflies to your garden. But unfortunately these hungry predators tend to arrive later than the greenfly thus allowing the pests to become firmly established first.
Aphids
Blue tits will feed on the larvae of aphids in winter if you expose your soil to them. But as aphids can travel long distances, this will have no effect on the ones that are coming from your neighbors.
Natural Cures
There are many home-made recipes for destroying aphids. Chopping up 10gms of garlic or 15gms of onions in a litre of water and spraying or watering the solution onto your plants is one cure. If using a sprayer be sure to strain the solution first.
Another common remedy used by organic gardeners is filling a bucket with nettles, covering them with water and leaving them to stand overnight before spraying on the effected plants.
For a spray to be effective, the foliage of your plants must be completely covered. As this is virtually impossible, its worth spraying a few times to make sure. Adding old fashioned soft soap which itself destroys many pests, will improve the ability of any natural spray to stick to leaves.
Derris
Derris, which is the least persistent of insecticides is sometimes used to deal with severe infestations. However as it kills the eggs and larvae of the ladybird this is a rather short-sighted solution. Better to try the biological control for aphids which is much easier to apply and will provide an interesting natural spectacle for you and your gardening friends.
