How to get rid of mealybugs on houseplants

December 20, 2025

Mealybugs are the little white fluffy things you find tucked into the joints of a houseplant, and most people's first thought is that it's some kind of mould, so it's worth knowing what they actually are, because once you know you're dealing with an insect the fix is pretty straightforward and it's mostly about being thorough rather than buying anything fancy.

What a mealybug is

A mealybug is a small soft bodied insect that covers itself in a white waxy coating, so it looks like a speck of cotton wool rather than a bug. They sit still and suck the sap out of the plant, so a bad infestation shows up as yellowing leaves and a plant that just stops growing. They also drip a sticky sugary waste called honeydew, and that's what makes the leaves feel tacky and what grows the black sooty mould you sometimes see on the leaves underneath.

Where to look

They like the tight spots where a leaf meets the stem and the undersides of the leaves, and some kinds live on the roots as well, so if a plant is sulking and you can't find anything on top it's worth sliding it out of the pot and having a look at the root ball. Ants running up and down a pot plant are a good clue too, because ants farm them for the honeydew.

Getting rid of them

Move the plant away from your other plants first, because they walk and they hitch a ride on anything that brushes past. Then dip a cotton bud in methylated spirits or isopropyl alcohol and dab each bug you can see, which strips the waxy coat off and kills it, and it's worth testing it on one leaf first and waiting a day, because a few soft or hairy leaved plants mark easily.

Once you've cleaned off what you can see, a horticultural oil spray is the next step, because the oil coats and smothers the ones you missed. Check that the label lists mealybug and the kind of plant you're spraying, then give the leaf joints and the undersides a proper coat. Spray it in the shade or indoors out of direct sun so the leaves don't scorch.

Why they come back

The eggs sit under the same fluffy coating and a single wipe won't get them all, so plan on going over the plant again every week or so for about a month and you'll catch the young ones as they hatch. Wash the pot and saucer in warm soapy water while you're at it. If the roots are infested, repot into fresh potting mix and throw the old mix out rather than reusing it.

Keeping them out

Most mealybug problems arrive on a new plant, so it's worth keeping anything new away from the rest for a couple of weeks and checking the leaf joints before it joins them. A plant that isn't stressed copes far better too, and in my experience that usually comes down to not overwatering it and giving it enough light.

Shop related products

Multicrop EcoPest Oil Insect Spray. A horticultural oil concentrate for soft bodied pests, read the label for the plants it suits.
Brunnings White Oil RTU 1L. A ready to use oil spray, so there's no mixing.
Methylated Spirits 1 LT. For dabbing bugs off with a cotton bud.
Brunnings Premium Potting Mix 36L. Fresh mix for repotting a plant with mealybugs on the roots.

Did you know we also stock isopropyl alcohol in a small 125ml bottle in the shop, and it isn't on the website, so give us a ring on (08) 8536 4333 to check what's on the shelf.

The rest of the pest range is in our pest control collection and the potting mixes are in our garden centre, and if you bring a leaf in we'll have a look at it with you.