How to deal with pests

Red spider mite These are found on the underside of leaves where a fine web develops. They attack the foliage, causing a mottled appearance and, in severe cases, death of the plant.

They attack a wide range of greenhouse plants including peaches, cucumbers and tomatoes, and many ornamentals including fuchsias and pelargoniums. To suppress red spider mite, damp the glasshouse down regularly during summer to raise humidity. Whitefly These are tiny, pure-white insects which reproduce quickly, laying white eggs on the undersides of leaves. They suck sap from the leaf undersides of tomato, cucumber and many ornamental plants, which can result in stunted growth. They also excrete a sugary substance called honeydew which makes the foliage sticky. Keep whitefly numbers down by suspending yellow adhesive strips above the plants. Vine weevil Often, you don’t spot vine weevil until it’s too late, by which time the soil-borne larvae will have devoured the roots of your plants. Cyclamen, fuchsias and primulas are susceptible. The grubs are creamy white, up to 10mm long and feast on plant roots and tubers. Vine weevil are hard to detect, but keep a lookout for the adults, which are grey beetles, about nine millimetres long, and have a distinctive snout.