Pest Management Guide for Australian Gardens
Updated October 2026
Pest control for aphids, caterpillars, fruit fly, slugs, whitefly and scale, mildest method first
Every garden has pests. The goal is not to eliminate them entirely but to keep damage at manageable levels using methods that do not harm beneficial insects, soil life, or your health. Organic pest management works by building a balanced garden ecosystem where predators keep pest numbers in check, and a registered product, used to the label, handles outbreaks that the gentler steps have not.
This guide covers the most common Australian garden pests and the registered products that suit them, used to the label. We do not give homemade spray recipes. For a symptom finder, seasonal calendar and disease guide, see the garden pests and diseases hub.
Common Garden Pests
Aphids
Small, soft-bodied insects that cluster on new growth, buds, and leaf undersides. They suck sap, distort growth, and excrete sticky honeydew that attracts sooty mould. Green, black, grey, and orange types are common.
Control: Blast off with a strong jet of water. If they persist, use a registered product whose label lists your crop and aphids, such as a pest oil. Encourage ladybirds, lacewings, and hoverflies, which eat aphids in large numbers.
Caterpillars
Larvae of moths and butterflies that chew holes in leaves, fruit, and stems. The cabbage white butterfly caterpillar is the most common pest of brassicas. Other types attack tomatoes, corn, and fruit trees.
Control: Handpick visible caterpillars. Spray with Dipel (Bacillus thuringiensis/Bt), a biological insecticide that only affects caterpillars and is safe for bees, beneficial insects, and humans. Reapply after rain.
Fruit Fly
Queensland fruit fly (QFF) is a devastating pest of stone fruit, citrus, tomatoes, capsicums, and many other crops. Female flies lay eggs inside ripening fruit. The maggots hatch and feed inside the fruit.
Control: Use protein bait traps to monitor and reduce numbers. Cover developing fruit with exclusion netting or individual fruit bags. Pick up all fallen fruit daily and dispose of it in sealed bags (not compost). Fruit fly is best managed with a combination of methods, not a single spray.
Slugs and Snails
Feed at night on soft foliage, seedlings, and strawberries. Leave silvery slime trails. Most active in wet weather.
Control: Iron-based snail pellets (sold as pet-safe and wildlife-safe) are the most effective option. Beer traps (a shallow dish of beer sunk into the ground) attract and drown slugs. Copper tape around pots creates a barrier. Water in the morning so the soil surface is drier at night.
Whitefly
Tiny white flying insects that cluster on leaf undersides. They suck sap and produce honeydew. Common on tomatoes, brassicas, and ornamentals.
Control: Yellow sticky traps catch adults. If numbers keep rising, spray leaf undersides with a registered pest oil, following the label. Encouraging beneficial insects (lacewings, parasitic wasps) provides long-term control.
Scale
Small, brown or white bumps on stems and leaves. Scale insects are stationary sap-suckers protected by a waxy shell. They weaken plants and produce sooty mould via honeydew. Common on citrus, olives, and many ornamentals.
Control: For small infestations, scrub the scale off with an old toothbrush dipped in water. For larger ones, spray thoroughly with a registered pest oil (white oil), covering all surfaces, and repeat at the interval the label gives.
Registered Products Guide
Use these only after hand removal, barriers, traps and beneficial insects have not been enough. Choose a product registered in Australia for your crop and pest, follow the label on rate, timing and the withholding period before harvest, and look up any product on the APVMA PubCRIS database. We do not give homemade recipes: home mixes of soap, oil, chilli, garlic, bicarbonate or neem have no tested rate, can scorch leaves and can kill the insects you want to keep.
Neem (ornamentals only)
Neem is made from the neem tree. The registered product, Eco-Neem, is labelled for ornamental plants only, so do not use neem on vegetables, herbs or fruit. On ornamentals, follow the label for rate and timing, and spray in the evening when bees are not foraging.
Pest Oil (White Oil)
Smothers soft-bodied insects and scale by blocking their breathing pores. Registered pest oils such as Eco-Oil are labelled for scale, aphids, mites and mealybugs on a range of crops.
- Buy a ready-made registered product and check that the label lists your crop
- Spray on a cool, dry day (not above 30 degrees)
- Cover all surfaces thoroughly
- Do not use on plants under water stress
Dipel (Bacillus thuringiensis / Bt)
A biological insecticide containing bacteria that kill caterpillars specifically. Safe for bees, ladybirds, humans, and pets. The gold standard for caterpillar control.
- Mix according to the label directions and check your crop is listed
- Spray on leaves where caterpillars are feeding
- Caterpillars stop feeding within hours and die within 2 to 3 days
- Reapply after rain and every 7 to 10 days during heavy infestations
Pyrethrum
Made from chrysanthemum flowers. A broad-spectrum insecticide that kills on contact. Effective against aphids, whitefly, thrips, and many other insects.
- Spray in the evening (breaks down rapidly in sunlight)
- Kills beneficial insects as well as pests, so use as a last resort, and use a registered product to the label
- Very short residual period (hours, not days)
- Do not spray on flowers where bees are active
Milk (the only kitchen mix)
For early powdery mildew on cucurbits and grapes, fresh cow's milk at one part milk to nine parts water, sprayed weekly in dry weather, is the only kitchen mix we suggest. It works best as prevention or at the first sign, and it will not clear a badly infected plant. The idea comes from Brazilian zucchini trials, and preliminary University of Adelaide vineyard trials reported in 2002 found milk comparable to standard mildew treatments.
Building a Pest-Resistant Garden
Sprays of any kind are a short-term fix. A genuinely pest-resistant garden relies on:
- Healthy soil: Plants growing in rich, living soil are naturally more resistant to pest damage
- Diversity: Mixed plantings with flowers, herbs, and vegetables attract beneficial insects and confuse pests
- Beneficial insects: Ladybirds, lacewings, hoverflies, and parasitic wasps eat pest insects. Plant flowers (alyssum, marigolds, dill, fennel) to attract them
- Companion planting: Strategic plant combinations can reduce pest pressure (see our companion planting guide)
- Good hygiene: Remove dead plant material, fallen fruit, and diseased leaves to reduce pest breeding sites
- Crop rotation: Do not plant the same crop family in the same spot year after year. This breaks pest and disease cycles
Pest and Disease Identification
Use these photos to identify common Australian garden pests, diseases, and beneficial insects.
Common Pests
Aphids
Caterpillar Cabbage Moth
Citrus Gall Wasp
Fruit Fly
Scale Insects
Snails Slugs
Spider Mites
Whitefly
Common Diseases
Black Spot
Blossom End Rot
Damping Off
Downy Mildew
Powdery Mildew
Rust
White Rot
Beneficial Insects
Hoverfly
Ladybird
Praying Mantis
Frequently Asked Questions
What is the best spray for aphids?
Start with a sharp jet of water and let ladybirds and lacewings do the work. For persistent infestations, use a registered product whose label lists your crop and aphids, such as a pest oil, and follow the label. Pyrethrum is a last resort because it also kills beneficial insects. We do not give homemade spray recipes. Always spray in the evening to avoid harming bees.
How do I control fruit fly organically?
Use a combination of methods: protein bait traps to monitor and reduce adult numbers, exclusion netting or fruit bags over developing fruit, and daily collection of fallen fruit. No single spray controls fruit fly effectively.
Can I use neem oil on my vegetables?
No. The registered neem product, Eco-Neem, is labelled for ornamental plants only, so do not use neem on vegetables, herbs or fruit. Whatever you spray, do it in the evening when bees have returned to their hives and keep it off open flowers.
Does milk spray work on powdery mildew?
It can help at the first sign of the disease. Fresh cow's milk at one part milk to nine parts water, sprayed weekly in dry weather, is the only kitchen mix we suggest. It works better as prevention than as a cure.
How do I get rid of slugs without harming pets?
Use iron-based snail pellets (labelled as pet-safe and wildlife-safe). They break down into iron and phosphate in the soil. Beer traps and copper tape are also effective non-toxic options.
