Sticky leaves, ants or black coating
Check stems, new shoots and leaf undersides for aphids, scale, mealybugs, whiteflies or psyllids. Sap-feeding insects can produce sticky honeydew, which attracts ants and may support black sooty mould.
Southern Plants GARDEN ADVICE
Notice changes early and help your plant recover.
Plants are living things and, just like us, they can sometimes become stressed or unwell. Most problems are easier to manage when noticed early, so regularly check the leaves, stems and soil for unusual changes.
Start with observation
What has changed?
A symptom can have several causes. Wilting, for example, may come from dry soil, damaged roots or waterlogging. Look closely before deciding that an insect or disease is responsible.
Powder, spots or unusual markings
White or grey powder may suggest powdery mildew. Rust-coloured pustules, dark spots or expanding dead areas can have different fungal, bacterial or environmental causes. Photograph the top and underside of affected leaves before removing them.
Holes, notches or chewed edges
Look in the evening and beneath leaves for caterpillars, beetles, weevils, slugs and snails. A small amount of chewing is often cosmetic and may also support birds and beneficial insects.
Webbing, stippling or distorted growth
Fine webbing and pale speckling can indicate mites. Twisted new growth may be associated with mites, thrips, aphids, herbicide exposure or other stress, so inspect carefully rather than treating from one symptom alone.
Yellowing or leaf drop
Check soil moisture, drainage, season and normal leaf age first. Yellowing can reflect water stress, nutrient availability, root damage or disease; chlorosis describes the symptom, not one diagnosis.
Wilting or decline despite wet soil
Stop adding water until you understand the cause. Persistent wetness, dark or soft roots and poor drainage may indicate root stress or root disease. Move pots out of standing water and seek specific advice before replanting affected soil.
A watch list is not a prediction or diagnosis. When a plant page names a pest or disease, it means the plant may be susceptible under favourable conditions—not that every plant will experience it.
A calm first response
What to do first
- Inspect the whole plant, including new growth, stems, leaf undersides and the soil surface.
- Check moisture at root depth and make sure pots and garden beds drain appropriately.
- Photograph the symptoms and any insects before cleaning or pruning.
- Separate an affected potted plant from nearby plants where practical.
- Remove only badly affected or dead material with clean tools; clean tools between plants.
- Identify the problem before applying a treatment. Even low-toxicity products can harm plants or beneficial insects when used incorrectly.
- If using a registered garden product, confirm that the label covers the plant and problem, and follow every label direction.
Trusted Australian guidance
Learn how to identify common problems
These independent resources provide photographs and more detailed explanations. Advice can vary by plant and conditions, so use identification guidance before choosing a response.
Pests and diseases overviewGardening Australia introduction to common indoor and garden problems.
Integrated pest managementManage problems through observation, prevention and multiple low-impact methods.
Recognising aphidsIdentification and practical guidance from Gardening Australia.
Recognising scale insectsAppearance, symptoms and management considerations.
Common fungal problemsIncludes powdery mildew and other fungal conditions.
Still unsure?Take clear photographs and ask a garden retailer or qualified horticultural professional for help.
Check advice for your particular plant
Open a plant page to see its approved Southern Plants watch list and personalised planting and care guidance.
Open Plant Finder