Houseplant troubleshoot
Houseplant Pests — How to ID and Treat
Learn guide
White fluff in leaf joints, dusty undersides, or sticky leaves are pests — not “dust.” Isolate the pot tonight. One spray does not finish a life cycle.
- Isolate first
- ID before spray
- Lights-off treatment
- Repeat 3×
Quick facts
| Mealybugs | White cotton in nodes; sticky honeydew |
|---|---|
| Spider mites | Fine webbing + stippled dusty leaves |
| Scale | Brown bumps that scrape off; sticky leaves |
| Aphids | Soft clusters on new growth |
| Fungus gnats | Tiny flies when you water — see dedicated guide |
| First move | Isolate + check every plant in the room |
| Spray window | Lights off, never hot sun or a heat vent |
| Pets | Keep cats away from treated leaves until dry |
Overview
Indoor pests arrive on new plants, cut flowers, or open windows. They explode when the mix stays wet and air is still. Identify first — mites and mealies need different contact, and gnats are a soil-moisture problem, not a leaf-spray problem.
Gnats: fungus gnats. Yellow leaves after spray damage or rot: yellow leaves · overwatering. Species: pothos · monstera · peace lily.
Treatment order
-
Step 1
Isolate and photograph
Move the pot away from the shelf. Photo nodes, undersides, and soil surface so you can track progress.
-
Step 2
Wipe what you can see
Alcohol on a cotton swab for mealy. Scrape scale. Rinse mites with a strong lukewarm shower on undersides.
-
Step 3
Spray contact product at lights-off
Insecticidal soap or diluted neem. Coat undersides and nodes. Test one leaf. Repeat every 5–7 days for three rounds.
-
Step 4
Fix the environment
Dry the top 2–3 cm for gnats. Increase airflow. Stop misting mite-prone plants.
-
Step 5
Quarantine new plants 2 weeks
New nursery pots are the #1 import path. Check nodes before they join the jungle.
Common problems
White fluff comes back in nodes
Why: Missed eggs / crawlers.
Fix: Third spray + swab. Check the pot rim and saucer.
Leaves stipple then drop
Why: Spider mites in dry AC air.
Fix: Shower undersides; soap 3×; raise humidity without soaking soil.
Sticky floor under the pot
Why: Honeydew from scale or mealy.
Fix: Treat the plant; wipe the floor — ants may follow honeydew outdoors.
Gnats after every watering
Why: Wet peat + adults laying.
Fix: Do not only spray leaves. Follow the fungus gnat guide.
Where pests hide by plant
- Pothos / monstera: nodes and aerial-root joints. Pothos.
- Peace lily: leaf undersides + wet peat gnats. Peace lily.
- Snake / ZZ: fewer leaf pests; watch gnats and scale on rhizome line.
- Urban shelf: one infested plant seeds the whole living-room jungle.
Gear for this species
Fungus gnats in soil — Leaf sprays do not fix gnat larvae — dry the top of the mix
FAQ
Is neem enough alone?
For crawlers, as part of three contact rounds. Not a systemic cure-all, and useless on gnat larvae in wet peat.
Can I use dish soap?
A true insecticidal soap is safer than random dish detergent, which can burn leaves.
Should I throw the plant away?
Only if it is fully covered and you cannot isolate. Most beginner plants recover after three rounds.
Do sticky traps treat mites?
No. Traps catch flying gnats. Mites live on leaves.
Is rubbing alcohol safe?
On a swab for mealy, yes. Do not drench the whole plant. Ventilate; keep off pets.
When can it return to the shelf?
After two clean weekly checks. Quarantine beats a second outbreak.
Aqua Plants Hub Editorial
