Tackle pests in the greenhouse

Biological controls will help keep them off your precious plants

Growing in a greenhouse has many advantages as it provides a perfect, protected environment for many plants to thrive. But the flipside is that these conditions also create ideal conditions for many pests – and if they’re not controlled they can cause a great deal of damage to plants.

The secret when dealing with any pest is to control it before it becomes a problem and gets too established. One method is to use biological controls which are increasingly popular with home gardeners. There’s now a good range of predatory mites, parasitic wasps, midges and nematodes that’ll control specific greenhouse pests such as glasshouse whitefly, red spider mite, mealy bugs, scale insect, thrips, aphids, vine weevils and slugs.

For biological controls to work, the pests need to be active on the plants and the normal time to use them is between April and the end of September, when temperatures are warmer.

Biological controls are normally bought by mail order from companies such as Agralan, Green Gardener and the Organic Gardening Catalogue. Once they’re introduced to the greenhouse, watering, feeding and ventilation are done as normal. It can take a few weeks for the predators to start working, so be patient and under no circumstances spray an insecticide as it’ll kill the biological control.

Apply now and in a few weeks your biological controls will keep pest sin check