Pest and insect sprays for battles in the garden

If left to run riot, garden pests can do serious damage to your precious plants, but with early detection and use of the correct pest sprays, most of these garden pests are not particularly difficult to control. We help you track down the right spray for insects in your garden...

Products used by domestic gardeners to deter garden pests fall into two categories: insecticides for sucking insects and insecticides for chewing insects. They are available as either dusts or sprays, but sprays tend to be more effective, as they provide more even coverage on the plants and are not as easily washed off.

Pest sprays for sucking insects

Sucking insects include mites, thrips, aphids and leaf hoppers. They suck sap from leaves, shoots, flower buds and stems and cause the collapse of plant cells, which in turn causes a plant to wilt. 

"To deter or kill these types of pests you need to use a 'systemic' insecticide spray; that is, one that is absorbed into the plant's sap stream," says Simon Powley, head horticulturist at All Green Nursery and Garden Supplies in Hoppers Crossing. "The insects are then poisoned by sucking the sap."

Some of the best insecticides for sap-sucking pests include pyrethrum-based chemicals, which are relatively low in toxicity and don't remain in the plant's system for very long. These are popular for use on edible plants such as vegetables, herbs and fruit trees.

Higher in toxicity, and therefore more effective, are insect spray varieties such as Bayer Confidor, Amgrow Chemspray Rogor 100, Yates Mavrik (which also deters chewing insects) and Folimat Garden Insecticide.

Pest sprays for chewing insects

Chewing insects include caterpillars, snails, slugs, weevils, beetles, grasshoppers, borers and fruit flies. They eat the plant tissue in leaves, buds, stems, flowers and fruit, and are controlled by using contact insecticides and stomach poisons. 

Pest sprays that are effective against chewing insects include Carbaryl and Dipel HG. "Carbaryl is quite toxic, so keep that in mind when using it on edible plants," says Simon. "Dipel is relatively new, and has been manufactured specifically to control caterpillars. This garden insect spray is reasonably low toxic and, like pyrethrum, is virtually harmless to beneficial insects like bees and ladybugs."

Lawn grubs, another type of chewing insect, can be a real problem in spring and summer, and are best controlled with a garden pest spray such as Bayer Baythroid Lawn Grub & Garden Insecticide or Hortico Lawn Grub and Insect Killer. There are also combination sprays available, such as Lanosan Tomato Spray and Yates Rose Shield, which treat diseases like fungus, as well as insects.

Always carefully read the instructions on the packaging of these pesticides, and only use them according to the directions. Never put 'just a splash more' into the mix, and try to use insect spray on calm days. Always wash your hands and equipment after spraying.

For advice on which spray to use to combat the pests in your garden, find a nursery in your area: