What you see
Fine pale dots on the top of the leaf, dull silvery patches and thin threads in the leaf axils and over the shoot tips.
Dry, warm air from a radiator is their best condition. That is why they turn up mostly in winter and spread to the neighboring plants quickly once they do.
Make sure before you treat
Hold the suspect leaf up to the light and look at the underside. The mites are yellowish, greenish or reddish and move very slowly. A hand lens or a phone photo at full zoom shows them clearly.
A sheet of paper works without a lens. Hold it under the shoot and tap the leaf twice. Anything that lands and then crawls across the paper is a mite. Dust stays put.
Misting the plant lightly with water is the other test. The webbing holds the droplets and shows up as a net, including in places where you saw nothing before.
The speckling is what separates spider mites from most other pests. Thrips leave larger silvery patches with small black dots of frass, and aphids leave the leaf sticky rather than dry.
Look at
- 01Leaf undersides held up against the light
- 02Pale speckles on the top of the leaf
- 03Fine threads in leaf axils and over shoot tips
- 04What falls onto a sheet of white paper
- 05Plants standing closest to a radiator
What to do now
Look at the leaf undersides against the light. Tap a leaf over white paper and watch for crawling dots, or mist the plant so the webbing becomes visible.
Separate the plant and rinse it thoroughly
Carry the plant out of the group as soon as you find them. Mites walk across leaves that touch, and they travel short distances through the air on their threads.
Then rinse it with lukewarm water, aimed upward at the leaf undersides. Tilt the pot so the water does not sit in the root ball, and bag the soil on smaller pots.
Cut out leaves that are heavily covered and already gray. They do not recover, and they carry the largest part of the colony.
Wipe out the windowsill, the cachepot and the saucer afterward. Mites also sit in the cracks around the rim of the pot and come back onto the plant from there.
What you see
The infestation sits on the leaf undersides and moves onto neighboring plants wherever leaves touch.
What to do now
Take the plant out of the group and rinse it with lukewarm water from below, pot tilted. Cut out grayed leaves and wipe the sill, the cachepot and the saucer.
What home remedies and higher humidity can do
Insecticidal soap in water works on contact. It kills only what it actually wets, so spray slowly and from below until leaf undersides, leaf axils and stalks are evenly damp. Anything you skip survives.
Dish soap is not a substitute. Its additives can leave spots and scorched edges on sensitive leaves. Test any solution on a single leaf and look at that leaf two days later before you spray the whole plant.
Oil-based products lay a film on the leaf and smother the mites. On hairy leaves, on succulents with a powdery bloom and on young growth they can cause damage, so the leaf test applies here too. Never treat in full sun and never on a dry root ball.
Higher humidity slows the mites down and does not end an infestation that is already running. Grouping plants together, a pebble tray and a spot further from the radiator are prevention, not treatment.
The plastic bag over the plant does hold the humidity up. Over more than a few days it does more harm than good, because fungi have an easy time in still, damp air.
The follow-up check decides
Spider mites develop fast in warm indoor air, and the eggs survive any mechanical treatment. A single round is never enough.
Look at the same places every two or three days: leaf undersides, leaf axils, shoot tips and the area around the leaf stalk. If you find mites or fresh threads again, treat again the same day.
Only after two checks in a row turn up nothing does the plant go back with the others. Keep going over the neighboring plants for weeks after that, because a second pot is often quietly infested as well.
Predatory mites are the biological route for indoor use. They need several weeks and a plant that is not sprayed again in that time, and they work more reliably in a densely planted corner than on a single pot.
What you see
Fresh threads and new speckling in the same places. Eggs survive every mechanical treatment, so the mites come back.
What to do now
Check every two or three days and treat again the same day you find anything. Move the plant back only after two clear checks, and keep watching its neighbors.
Why they show up in winter
Air from a radiator is warm and dry, and that is exactly where spider mites breed fastest. A plant sitting directly above a radiator is the usual starting point in a home.
Move sensitive plants further from the heat over winter and group them together or stand them on a pebble tray. Palms, ivy and thin-leaved species are the usual first victims.
New plants bring the infestation in. Keep every new arrival on its own for two or three weeks and go over the leaf undersides regularly in that time.
Dusty leaves make the check harder and hide the fine speckling. Wipe large leaves down regularly and you will catch an infestation earlier.
What you see
The infestation usually starts on a plant in dry air near a radiator, or on a plant that came home recently.
What to do now
Move sensitive plants away from the radiator over winter and group them or stand them on a pebble tray. Keep new plants separate for two or three weeks and check their leaf undersides.
What is left when the mites are gone
Speckled, silvery gray leaves do not turn green again. They stay that way until they drop, and you cut them off only if the plant keeps enough healthy foliage.
New growth tells you whether you are through. If it comes in evenly green and without dots, the treatment worked.
A badly weakened plant needs time rather than fertilizer. Give it a bright spot, water by the finger test and wait with feeding until it grows again.
Whether a plant is a problem around pets or children is covered in its own care guide. If you suspect poisoning, a vet or a doctor is the right call.
Related plants
Keep reading
Common questions
What kills spider mites on plants?
Separating the plant, rinsing it thoroughly from below and checking it consistently afterward. One treatment never reaches the eggs, so the repetition is what decides the outcome. Contact treatments work only where they actually wet the mites.
How do you get rid of spider mites on plants naturally?
Lukewarm water is the most effective and gentlest option. Insecticidal soap in water adds to it, but only where the leaf undersides are wetted completely. Dish soap does not belong on the list, because its additives can damage leaves.
What do spider mites look like on houseplants?
You see fine pale dots on the top of the leaf and thin threads in the leaf axils before you see the mites. Tap a suspect leaf over white paper and watch for tiny moving dots. A light mist of water makes the webbing visible.
Does humidity kill spider mites?
It slows them down and does not end an infestation that has already started. Use it as winter prevention by moving sensitive plants away from the radiator and grouping them or standing them on a pebble tray. A bag left over the plant does more harm than good.
How long does it take to get rid of spider mites?
As long as it takes for two checks in a row to come up empty. Check every two or three days and treat again the same day you find anything. New mites hatch fast in warm rooms, so it usually runs several weeks.
Can spider mites spread to other plants?
Yes. They walk across leaves that touch and travel through the air on their threads. Separate an affected plant right away and go over its neighbors regularly for the following weeks.
Last reviewed: 2026-09-07