There are some garden visitors that love fresh, home grown vegetables as much as you do. These are the common pests and diseases of the veggie garden. They may attack the leaves, fruit or even roots of plants and many target specific vegies. If you know what to expect, it makes control easier. Here are some commonly encountered pests of vegetable gardens (and a disease too) and what to do if you find them.

Before reaching for a spray to control pests, carefully read the label as not all pesticides are registered to use on edible plants. Some also have a withholding period, which means the period of time that must elapse between spraying and harvest. It's vital that you abide by the directions provided.

It is also worth remembering that pest and disease outbreaks can occur when plants are stressed, for example by heat or drought. As well as controlling the pest, also improve plant care with extra watering, more sunlight (or shade if plants are heat stressed), applications of seaweed tonics and liquid fertiliser.


List of common veggie garden pests


Aphids are small green, black or colourless insects that usually attack soft new growth such as shoots, buds and flowers. Although the individual insects are small with tiny legs and occasionally small wings, these pests cluster together so are easy to find and squash or hose off plants. They suck sap from the plant they are feeding on, which damages growth and weakens the plant. They may also spread virus disease.

Before controlling aphids, check to see whether there are ladybirds or their larvae (babies) present as these insects feed on aphids and can help control them naturally. Small birds also feed on aphids. If a pesticide is used, select an organic spray - Flower Power recommends Yates Pyrethrum - which can be used on vegetables (see label) and apply according to instructions. Don’t spray when bees are active or on windy days, and always remember to observe the recommended withholding period. The feeding of aphids also causes a secondary issue of sooty mould, a black mould that grows where sticky, sugary exudate from the aphids falls on foliage. Sooty mould affects growth. It is controlled by removing aphids and by applying a soap spray – look for commercially available products such as Nature's Way Natrasoap Vegie & Herb Spray, as these are unlikely to damage plants.


Cabbage white butterfly caterpillars

The white butterflies flitting around the garden are looking for leaves on brassica plants (such as cabbage or broccoli) to lay eggs. The small yellow eggs often appear in clusters on the back of leaves. Squashing them provides very effective control. If the eggs are missed and allowed to hatch, the small green caterpillars quickly spread out across the leaf causing ragged chewed holes. As they feed, they get bigger before they pupate.

These caterpillars are very damaging to vegetables and can be hard to see. If you spot damaged leaves, look closely especially along the midrib of the leaf and on both the back and front of the leaf. Control ranges from squashing eggs and caterpillars to protecting plants from attack by covering them with fine white netting to exclude the female from laying eggs. The natural insecticide Nature's Way Caterpillar Killer Dipel can be used with safety as it targets these caterpillars not other insects. There are also other organic pesticides available for controlling caterpillars.


Fruit fly

This little fly is one of the most damaging insects for fruit and vegetable growers in warm climates. Fruit fly attacks soft fruit such as tomato and capsicum. It's most active in summer, but may also be active from spring to autumn if conditions are warm. Fruit is attacked as it begins to ripen. The adult fly is rarely seen but its larvae are very evident. These are tiny, white, wriggling maggots, which are found through fruit causing it to rot and fall to the ground. Damaged fruit may show signs of ‘stings’ (puncture marks) on the skin.

All soft-fruited crops must be protected in areas where fruit fly is active. Use fine exclusion netting or bags to prevent access by the adult, set up fruit fly traps, or apply splash baits such as eco-naturalure that attract and kill females before they lay. A combination of all three methods may be needed. Fruit that ripens indoors – such as tomatoes – can be picked green, before pest attack occurs and ripened indoors.


Green vegetable bugs

These are one of the stinkbugs that attack fruit and vegetables and suck sap. Green vegetable bugs are attracted to many vegetables and fruit, including beans and raspberries, and may also be found on ornamental plants. As their name suggests they are green so are hard to see among green leaves and stems. The bugs are shield shaped and about 13mm long. When disturbed, they drop from the plant or fly off. If touched or squashed they emit a foul smell - hence the common name, ‘stink’ bug.

Control by encouraging them to drop into a container filled with soapy water, or simply catch and squash (wear gloves and eye protection). Also watch out for juveniles that are small and black or green, sometimes with colourful markings. These may be able to be controlled with pest oils, such as eco-oil or PestOil. There are also larger stinkbugs found on citrus such as bronze orange bugs and spined citrus bugs.


Powdery mildew

This is a fungal disease seen on foliage, stems and some fruit as a white powder. Powdery mildew is prevalent on many plants as they near the end of their productive life, but particularly zucchini and pumpkin. Once powdery mildew appears, crops will be reduced and leaves will die off.

Fungal diseases such as powdery mildew can be controlled with fungicides - Flower Power recommends eco-fungicide. When selecting a fungicide, always check the label for suitability for use on edibles and apply as directed on the label. Milk sprays - a home-made spray with 1 part full cream milk to 9-10 parts water - are a popular home remedy, or you can simply remove affected growth. If plants are at the end of their productive life, simply remove the plant and bin.


Slugs and snails

Slugs and snails are commonly encountered in vegetable gardens and are particularly damaging to young vegetables. They eat leaves and can chew small plants to ground level. They are mostly active at night and particularly after or during rain. Slimy trails on paths or around plants are an indication of snail or slug activity.

To control these pests use baits, for example Multiguard Snail & Slug Killer Pellets. Generally speaking, organic baits based on iron are the safest to use in gardens as they are less toxic to pets or other wildlife. Home-made traps such as saucers of beer or up-turned orange skins can also be effective. or you can simply collect the insects and squash them or drown them in a bucket of soapy or salty water. Also check hiding areas such as under pot rims, around garden edges or in the base of plants.



If tiny, white insects fly up when you approach or touch the leaves of a plant you are seeing whitefly. Whiteflies also hide underneath leaves. This is a pest that sucks sap from plants and can weaken growth and also spread disease. They may be seen on tomatoes, brassicas and many other vegetables and ornamental plants such as fuchsias.

Whitefly are resistant to most chemicals so are hard to control with sprays. Check the label on products registered for whitefly to ensure they're suitable to use on edibles. They can be trapped on yellow sticky traps in a glasshouse situation, however these are unsuitable to use outdoors, as they could trap beneficial insects or even small birds. Carefully remove leaves that are sheltering whitefly or have eggs. Put the leaves straight into a bag to prevent the whitefly escaping to other parts of the garden. Whitefly may indicate that plants are too closely planted or overfertilised with high-nitrogen fertiliser, which encourages large, sappy leaves that are attractive to pests. Providing extra watering may help plants that are attacked by whitefly. You could also consider planting native flowering plants around your veggie patch - this will attract small native birds who tend to eat pests such as whitefly.