Common Cannabis Pests and How to Deal With Them 🐛🕷️🦟Updated 6 hours ago
Pests are one of the biggest challenges for cannabis growers. They can weaken plants, damage buds, and reduce yields if not controlled quickly. Knowing what to look for and how to respond, is key to protecting your grow.
🕷️ Spider Mites
Signs: Fine webbing, yellow speckling on leaves, tiny moving dots under the leaf surface.
Control: Water sprays, predatory mites (Phytoseiulus persimilis), insecticidal soap, or neem oil (early veg only).
🦟 Fungus Gnats
Signs: Tiny black flies hovering near soil, larvae feeding on roots.
Control: Let the topsoil dry, add sticky traps, use a biological control like Bacillus thuringiensis israelensis (BTi).
🦋 Caterpillars & Budworms
Signs: Chewed leaves, boreholes in buds, frass (caterpillar droppings).
Control: Hand-pick, use Bacillus thuringiensis kurstaki (BTk), apply netting outdoors to keep moths away.
🐞 Aphids
Signs: Clusters of soft-bodied insects on stems and leaves, honeydew (sticky residue), ant activity nearby.
Control: Blast with water, apply insecticidal soap or neem in veg, release ladybugs or lacewings.
🪰 Whiteflies
Signs: Tiny white moth-like insects that scatter when disturbed, sticky honeydew on leaves.
Control: Yellow sticky traps, insecticidal soap, neem (veg stage), or predatory wasps (Encarsia formosa).
🪳 Thrips
Signs: Silvery streaks or speckling on leaves, tiny cigar-shaped insects.
Control: Blue sticky traps, neem or insecticidal soap in veg, predatory bugs like Orius insidiosus.
🪲 Root Aphids
Signs: Stunted growth, yellowing, white fuzz or clusters on roots, often mistaken for nutrient issues.
Control: Beneficial nematodes, soil drenches with insecticidal soap, maintaining healthy root aeration.
🦟 Mosquitoes (Greenhouse/Outdoor)
Signs: Usually more of a nuisance than a crop threat, but can breed in standing water.
Control: Eliminate standing water, use BTi dunks in reservoirs or trays.
🌱 Prevention Tips
Keep your grow clean and free of dead leaves.
Maintain proper airflow and humidity.
Quarantine new plants before introducing them to your grow space.
Regularly inspect leaves (especially undersides).