Ever feel like the moment your plants look perfect, something small and sneaky moves in to ruin the show? You’re not imagining it. In Australia, each season brings its own set of uninvited guests. This guide breaks down exactly which pest shows up when, with quick links to deeper how-tos and gentle products that work.
Not Sure What Pest You’re Dealing With? Start With the Damage
Before jumping to the season, it helps to identify what kind of damage you’re seeing. Many garden pests leave very recognisable signs.
Sticky leaves, ants, or black sooty mould
Often caused by sap-sucking pests like aphids, scale, whitefly or mealybugs. The sticky residue (honeydew) attracts ants and leads to mould growth.
Fine speckling on leaves or webbing underneath
Common signs of spider mites, especially in hot, dry weather. Leaves may look dusty, faded or bronzed.
New growth curled, twisted or distorted
Usually linked to aphids or thrips, which target soft, young growth early in the season.
Seedlings chewed overnight or large ragged holes
Likely slugs or snails, particularly after rain or in shaded garden beds.
If you’re still unsure, flip the leaf over, check stems and the soil surface, and note when the damage appeared — timing is often the biggest clue.
Simple Pest Prevention That Works Year-Round
The healthiest gardens tend to have fewer pest problems. These basic habits reduce outbreaks before they start:
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Keep things tidy – Remove spent crops, fallen fruit and heavily infested leaves.
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Rotate crops – Avoid planting the same crop family in the same spot each season.
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Encourage airflow – Crowded plants and damp foliage invite pests and disease.
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Check plants regularly – Early detection is far easier to manage than a full infestation.
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Use physical barriers early – Netting and collars work best before pests arrive.
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Time your traps – Sticky cards and monitoring traps are most useful at the start of the season.
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Support plant health – Well-fed, well-watered plants are naturally more pest-resistant.
These small steps reduce the need for stronger interventions later on.
Not All Bugs Are Bad
Many insects in your garden are doing important work for you. Ladybirds, lacewings, hoverflies and parasitic wasps all help keep pest populations in check.
To support beneficial insects:
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Avoid broad-spectrum sprays unless absolutely necessary
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Leave some flowering herbs or natives to provide food and shelter
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Spot-treat pests rather than spraying the whole garden
If you’re seeing beneficial insects around, that’s often a sign your garden is finding its own balance.
Why Pest Seasons Aren’t as Predictable as They Used to Be
While pests tend to follow seasonal patterns, weather plays an increasingly big role.
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Warm winters can allow pests to survive longer and appear earlier
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Hot, dry spells favour mites and thrips
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Humid conditions increase sap-suckers and fungal issues
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Rain after dry periods often triggers slug, snail and millipede activity
Instead of watching the calendar alone, pay attention to temperature, rainfall and plant growth stage. Pest pressure often follows conditions, not dates.
Spring (September to November)
New shoots are like an all-you-can-eat buffet, so start scouting weekly.
- Aphids and whiteflies pile onto soft growth. Start with a gentle soap or neem, then follow up if needed with an organic Pyrethrum spray.
- Cabbage white caterpillars appear on brassicas & leafy plants. Hand pick them off early and net seedlings to prevent egg laying. Pyrethrum can be used to control caterpillars
- Thrips scar leaves and flowers and can spread plant viruses and disease. Learn how to ID the pests early, use blue sticky traps, and low-toxic sprays such as pyrethrum.
- Citrus leafminer curls fresh citrus leaves. Prune lightly, protect soft flushes of new growth, and keep trees unstressed. Hang blue sticky traps around plants to help lure them away from fresh growth.
- Garden weevils and wingless grasshoppers chew rough holes in leaves overnight. Night checks help you catch them in the act. Diatomaceous earth is effective at controlling these garden pests.
Summer (December to February)
Heat speeds everything up. Keep leaves clean, water consistently, and inspect the undersides.
- Spider mites leave behind speckled leaves, which then turn the leaves bronze. Raise the humidity a touch if you can, rinse dusty foliage off with a water and a neem oil solution, and act early by daily scouting. Systemic pesticides may be necessary to use in severe infestations, if you require a fast fix, we recommend Kill-a-mite for fast acting results.
- Scale and mealybugs ooze out honeydew that becomes a home sooty mould on citrus, roses, and figs. Get the step-by-step plan in How to Control Scale Insects.
- Fruit fly targets ripening crops like tomatoes and stone fruit. Hang traps before colour change, pick promptly, and bin spoiled fruit.
- Fungus gnats boom in warm, damp potting mixes and hydroponic media like coco coir. Products like T-Drops and Diatomaceous earth are affective natural controls. If the infestation is severe, a systemic product such as Scarid10 might be your best bet. Break the life cycle with the tips in How to Get Rid of Fungus Gnats.
Autumn (March to May)
Cooler, wetter weather changes the enemy list.
- Snails and slugs return with the first rains. Set an organic snail bait, use beer traps, and tidy low growing plants where they hide under the foliage.
- Portuguese millipedes sometimes swarm and nibble soft fruit touching soil. Lift fruit and use simple barriers such as diatomaceous earth.
- Rodents look for new food sources after harvests. Clear fallen fruit and use mesh to protect compost poles.
- Dealing with a mix of nibblers and sap-suckers at once? Read Natural Pest Control Tips for Aussie Gardens for seven habits that work year round.
Winter (June to August)
Things slow outside, but indoor jungles keep humming.
- Scale and mealybugs on houseplants stay active. Move plants to bright spots if the sun has changed position, wipe leaves with mild soapy water or a neem oil solution, and visit our scale guide to learn more battle tactics for stubborn cases.
- Fungus gnats linger indoors if potting mix stays wet. Let the top couple of centimeters dry and use sticky cards near pots.
If You See Something Unusual
If you notice a pest you don’t recognise, or damage that doesn’t match common garden pests:
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Avoid moving affected plants or soil
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Take clear photos (including the plant, pest, and damage)
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Seek advice from a local nursery, garden professional or state agriculture department
Early identification helps protect not just your garden, but others as well.
Year-round prevention
- Feed and water plants consistently. Stressed plants are easy targets.
- Rotate crops and clear spent growth.
- Quarantine new plants before adding them to your collection.
- Encourage beneficial insects by planting nectar-rich herbs.
In short, pests are part of a living garden. With the right timing and a light touch, you’ll stay ahead and keep everything thriving.
Explore all our gentle, high-performing solutions in the Pest Control collection.
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