Learn to identify the common pests and to distinguish them from gardeners’ allies, such as ladybugs, lacewings, centipedes, hoverflies and ground beetles and their larval, immature forms. Some pests, such as froghoppers (cuckoo spit), are simply a nuisance and may be ignored, whereas others like the beautiful lily beetle can be a serious threat.
When problems do occur, try to use physical and specific biological controls or sprays, rather than general insecticides that kill a wide range of insects. Larger pests like beetles, caterpillars and snails, for example, can be picked off by hand, while forceful spraying with water will deter red spider mites and dislodge other pests such as greenfly.
- Grow pest or disease-resistant varieties.
- Mingle flowers with vegetables to hide those that are vulnerable to attack.
- Physical barriers such as fleece can protect brassicas from caterpillars and carrots from root flies.
- Use netting over fruit to deter birds.
- Grow flat-headed flowers such as achilleas, asters, marigolds and sedums to attract insect predators.
- Use traps to catch fruit moths, slugs and flying greenhouse pests.
If you do spray, remember that contact insecticides such as derris are effective but short-lived, whereas systemic chemicals are absorbed and remain in the plant for several days, which can delay the harvesting of vegetables and fruit.
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When getting rid of pests, be careful not to deter friendly insects, such as ladybugs.
