Mealybugs: white fluffy spots on plants and what to do
Mealybugs are small sap-sucking insects covered in white, waxy fluff that hide in leaf joints and under leaves, and they are common on succulents, orchids and many houseplants. Move the plant away from the others, wipe off every one you can see with a damp cotton bud, and check again every few days for several weeks.
What does it look like?
- White, cottony clumps in leaf joints, on stems and under leaves.
- Sticky honeydew on leaves, sometimes with black sooty mould on it.
- Slow growth, yellowing or dropping leaves.
Why does it happen?
- A new plant brought home with mealybugs on it.
- Insects moving between plants that touch.
What can you do about it?
- Move the plant away from your other plants.
- Wipe off every mealybug you can see with a cotton bud or soft cloth dampened with water, including in leaf joints and under leaves.
- Rinse the plant with lukewarm water where it can take it.
- Check again every few days for several weeks, since eggs and young hide well.
- If they keep coming back, an insecticidal soap or horticultural oil can help: follow the product label, check it is approved for home use where you live, wear gloves, and keep children and pets away until it is dry.
When you photograph a plant with this problem, Leafsight gives an assessment that names the likely problem, how serious it looks and how sure it is. Your first assessment that finds a problem includes care steps like these; with Pro or a one-time unlock, every one does.
When should you look closer?
- White fluff on the roots when you repot: root mealybugs need the soil replaced.
- Several plants affected at once.
Questions
How do I get rid of mealybugs on a houseplant?
Move the plant away from your other plants, then wipe off every mealybug you can see with a cotton bud or soft cloth dampened with water, including in leaf joints and under leaves. Rinse the plant with lukewarm water where it can take it, and check again every few days for several weeks, since eggs and young hide well. If they keep returning, use an insecticidal soap or horticultural oil at the label rate.
Where do mealybugs come from?
Mealybugs usually arrive on a new plant, hidden in leaf joints, under leaves or on the roots, and then crawl to plants that touch it. They don't come from the soil itself or from watering. Checking new plants closely and keeping them apart from your collection for a few weeks is the simplest way to keep mealybugs from spreading through your plants.
Is the white fluff on my plant mealybugs or mould?
Mealybugs look like small, white, cottony clumps, mostly in leaf joints, along stems and under leaves, and a close look shows an oval insect that can move slowly. Mould on the soil surface is flat and fuzzy and doesn't sit in leaf joints. Powdery mildew is a thin white dusting on the upper side of leaves rather than raised clumps.
Can mealybugs live in the soil?
Yes. Root mealybugs live on the roots and show up as white, waxy fluff on the root ball when you take the plant out of its pot. A plant with root mealybugs often grows slowly or wilts for no clear reason. Replacing the soil, rinsing the roots and repotting into a clean pot is the usual first step, and nearby plants are worth checking too.
Can mealybugs spread to my other plants?
Yes. Mealybugs move between plants whose leaves touch, and the young crawl to plants nearby, so a whole windowsill can be affected before you notice. Check the neighbours of an affected plant, and keep it apart until several weeks pass with none found.
Not sure? Check with a photo
Leafsight looks at a photo of the leaf, asks a few questions about light, watering and drainage, and gives an assessment of the likely problem with care steps. A photo assessment can be wrong: for a hands-on look, ask a local garden centre or plant clinic.
Related problems
- Spider mites on plants: how to spot them and what to do
- Aphids on plants: how to spot them and what to do
- Fungus gnats in houseplant soil: why they appear and how to get rid of them
- Yellow leaves on houseplants: common causes and what to check
Sources
Updated 2026-11-04. All plant problems.
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