Much ancient lore exists about plants which help each other to flourish and to combat predators. This age old phenomenon is now becoming a far more acceptable solution for maintaining a healthy garden environment.
Bitter herbs such as southernwood, wormwood, rue and mug wort will not only repel slugs and insects, but will also help to discourage birds and mice from eating newly planted seeds.
Simply dry the herbs in bunches by hanging them in a cool, airy place for four to 12 days, and then powder the leaves by rubbing them through a fine wire sieve. Spread the powdered herb over the ground and cover with a sprinkling of earth.
Garlic is another herb which enjoys a high reputation in the garden for repelling insect pests when grown among other plants. Agriculturists of old used to plant garlic near their onions, cabbages and garden vegetables to keep away various flies and grubs.
Mustard is also an excellent pesticide. Grow a bed of it, and when in flower cut it and dig into the ground to eliminate insect pests and their eggs. Cayenne (chili) pepper, dried and powdered, can be dusted on cabbages, cauliflowers, tomato plants, to kill caterpillars. When grinding up the cayenne chili be sure to wear rubber gloves, and do not touch your face, mouth or eyes – it burns and irritates for quite a long time.
Other herbs can be made into effective, environmentally safe garden insecticides and fungicides. Feverfew, for instance, a small self-seeding, rather fragrant member of the daisy family can be made into a broad spectrum spray to control a wide range of garden pests.
However, like all organic sprays it breaks down quickly; so if you spray one day and have pests a week later, don’t blame the feverfew. It would have killed them, it’s just that more pests would have moved in.
Make your garden spray by steeping four tablespoons of feverfew flowers in one liter of hot, soapy water for one hour, then strain. Cool before using. Spray at night outdoors so that it doesn’t affect bees and other useful insects.
To help destroy and control damping-off fungus and powdery and downy mildew you can make a natural fungicide from chamomile flowers. Put one cup of the flowers in a non-metallic bowl, cover with three cups of boiling water, cover and steep overnight. Strain through muslin cloth, squeezing out all the liquid, and spray onto affected plants.
Ground mustard seeds can be used as an effective dusting powder for the control of powdery mildew. Grind into a fine powder with a pestle and mortar and store in a plastic bottle with holes in its lid. Dust on affected plants as required until problem is under control.