Indoor Plant Pests: The Complete Guide

Even the most experienced plant parents face pests. The key is early identification and swift action. Here's everything you need to know about the 7 most common indoor plant pests.

1. Fungus Gnats

Looks like: Tiny, dark flies hovering around soil

Damages: Larvae feed on roots and organic matter in moist soil

Best treatment:

• Allow soil to dry out between waterings (larvae need moisture to survive)

• Yellow sticky traps for adults

• Hydrogen peroxide drench (1:4 ratio with water) kills larvae

• Beneficial nematodes (Steinernema feltiae) — organic, highly effective

2. Spider Mites

Looks like: Tiny white or red dots on undersides of leaves; fine webbing

Damages: Pierce leaf cells, causing stippled yellowing; serious infestations kill plants

Best treatment:

• Isolate immediately — spider mites spread fast

• Spray with strong water stream to knock off mites

• Neem oil spray (weekly for 3–4 weeks)

• Insecticidal soap spray

3. Mealybugs

Looks like: White, cottony clusters in leaf axils and on stems

Damages: Suck sap, secrete honeydew (sticky substance), weaken plants

Best treatment:

• Dab individual bugs with alcohol-soaked cotton swab

• Spray with 70% isopropyl alcohol diluted 50/50 with water

• Neem oil spray weekly

4. Scale

Looks like: Brown, shell-like bumps on stems and leaves

Damages: Suck sap; hard shell makes them resistant to sprays

Best treatment:

• Physically remove with a soft toothbrush dipped in soapy water

• Neem oil (must penetrate shell)

• Systemic insecticide for severe infestations

5. Aphids

Looks like: Tiny green, yellow, or black soft-bodied insects clustering on new growth

Damages: Suck sap from tender new shoots, causing distorted growth

Best treatment:

• Knock off with strong water spray

• Insecticidal soap spray

• Neem oil

• Introduce beneficial insects outdoors (ladybugs eat aphids)

6. Thrips

Looks like: Tiny, slender yellow or brown insects; silvery streaks or stippling on leaves

Damages: Rasp leaf tissue, spreading plant viruses

Best treatment:

• Blue sticky traps (thrips are attracted to blue)

• Spinosad spray (organic, highly effective)

• Neem oil spray

7. Root Mealybugs

Looks like: White waxy coating on roots (only visible during repotting)

Damages: Feed on roots, causing wilting and decline that resembles overwatering

Best treatment:

• Bare-root the plant and wash all soil from roots

• Submerge roots in insecticidal soap solution for 10 minutes

• Repot in fresh, sterile soil

Universal Prevention

• **Inspect new plants** before bringing them home; quarantine for 2 weeks

• **Avoid overwatering** — moist soil attracts fungus gnats

• **Maintain airflow** — stagnant air encourages mites

• **Monthly neem oil spray** as a preventative on all plants

• **Keep plants healthy** — stressed plants attract pests