BloomprintHow to get rid of houseplant bugs
Plant problems · Updated August 5, 2026 · 2 min read
Short answer
Identify the pest first; the treatment differs completely between them. Then isolate the plant, clean it mechanically, and apply insecticidal soap or neem every 5–7 days, three to four times — a single application never works, because it does not kill eggs.
Almost everything you meet indoors is one of six pests. The right treatment depends entirely on getting that identification right: what works on fungus gnats does nothing to spider mites.
Which pest?
Fungus gnats
Small black flies, 2–3 mm, drifting over the soil. The adults are harmless; the larvae live in wet soil. Fungus gnats are less a pest than a symptom of overwatering.
Fix: let the top 3–4 cm of soil dry completely between waterings. Yellow sticky traps catch adults. A 1 cm layer of sand or perlite on the surface makes it hard for females to lay.
Spider mites
Barely visible dots. The signs are pinprick pale stippling on the leaf and fine webbing underneath and at stem joints. They explode in dry, warm air.
Fix: rinse the whole plant in the shower, undersides included, then apply insecticidal soap or neem four times at five-day intervals. Raising humidity slows them down.
Mealybugs
White cottony clusters in leaf joints and on undersides. They move, slowly.
Fix: dab each one with a cotton bud dipped in 70% alcohol — by far the most effective method — then treat the whole plant with insecticidal soap, three times at seven-day intervals.
Scale
Brown, immobile bumps 2–4 mm across on stems and leaf veins, which scrape off with a fingernail. They leave sticky honeydew on the leaves and the floor below.
Fix: scrape them off, then wipe with alcohol. The shell protects them from sprays, so the mechanical step is essential.
Aphids
Clusters of 2 mm green, black or brown insects on new growth. They breed fast and leave sticky residue.
Fix: knock them off with a strong jet of water, then apply insecticidal soap.
Thrips
Silvery streaks on leaves with tiny black specks (droppings). The insect itself is slim and about 1 mm long.
Fix: blue sticky traps plus neem, four applications at five-day intervals. One of the most stubborn indoor pests.
Five steps that always apply
- Isolate. Move the affected plant at least two metres from the others.
- Clean mechanically. Shower, alcohol swab, scrape. This drops the population enough for treatment to finish the job.
- Treat. Insecticidal soap or neem. Wet the undersides — that is where most pests live.
- Repeat. Three to four times, 5–7 days apart. Eggs survive the spray, which is why a single application always fails.
- Check the neighbours weekly for two weeks.
What not to do
- Dish detergent instead of insecticidal soap. It strips the leaf's protective layer and can scorch it.
- Treating in direct sun. Oil plus sun equals burn. Treat in the evening or in shade.
- Stopping after one application. The single most common mistake.
- Replacing all the soil. Apart from fungus gnats, these pests live on the leaves; repotting is stress without benefit.
Frequently asked questions
Do fungus gnats actually harm the plant?
Adults do essentially no harm to an established plant. Very heavy larval populations can damage seedlings and fine roots. The real message is that your soil is staying too wet.
Neem oil or insecticidal soap?
Soap kills soft-bodied insects on contact but leaves no residue. Neem kills on contact and also disrupts feeding and development for a few days. Neem is usually more effective; soap is faster.
When should I give up on a plant?
If more than half the foliage is damaged, the stems are affected, and the population is still rising after three treatments, discarding it is the safest way to protect the rest.
Can I do this without chemicals?
For light infestations, yes: alcohol swabs, a shower, sticky traps and a change in watering are often enough. A widespread mite or thrips outbreak rarely clears mechanically.