Cannabis Troubleshooting Hub
Something wrong with your plants? Don't panic. Use our visual guides to diagnose and fix nutrient deficiencies, pest infestations, and diseases before they ruin your harvest.
Quick Symptom Checker
| Symptom | Likely Cause | Guide |
|---|---|---|
| Yellow lower leaves | Nitrogen deficiency | Learn More |
| Yellow leaves with green veins | Iron or Magnesium deficiency | Learn More |
| Brown/burnt leaf tips | Nutrient burn or potassium deficiency | Learn More |
| Curling leaves (upward) | Heat stress or light burn | Learn More |
| Curling leaves (downward) | Nitrogen toxicity or overwatering | Learn More |
| White powdery spots | Powdery mildew | Learn More |
| Tiny webs on leaves | Spider mites | Learn More |
| Gray/brown rot on buds | Bud rot (Botrytis) | Learn More |
| Small flies near soil | Fungus gnats | Learn More |
| Seedling collapses at base | Damping off | Learn More |
Troubleshooting Guides
Nutrient Deficiencies
Yellow leaves? Brown spots? Learn to identify nitrogen, phosphorus, potassium, calcium, and magnesium deficiencies with our visual chart.
Pests & Bugs
Spider mites, thrips, fungus gnats, and aphids can devastate your grow. Learn to identify, prevent, and eliminate common cannabis pests.
Diseases & Mold
Powdery mildew, bud rot, root rot, and damping off can destroy your harvest. Prevention and treatment for fungal and bacterial diseases.
Prevention: The 4 Root Causes
Most cannabis problems stem from just four environmental factors. Master these, and you'll prevent 90% of issues before they start.
Watering
Overwatering is the #1 beginner mistake. Let soil dry between waterings. Lift pots to gauge weight.
pH Balance
Wrong pH causes nutrient lockout. Target 6.0-7.0 (soil) or 5.5-6.5 (hydro). Always pH your water.
Temperature
Too hot (85°F+) or cold (60°F-) stresses plants and invites pests. Keep 70-80°F for healthy growth.
Airflow
Stagnant air breeds mold and pests. Use oscillating fans. Good airflow strengthens stems too.
Common Questions
Why are my cannabis leaves turning yellow?
Yellow leaves can indicate: nitrogen deficiency (lower leaves yellow first), overwatering (droopy + yellow), pH imbalance (nutrient lockout), light burn (top leaves bleach), or natural senescence during late flowering. See our deficiency guide for visual ID.
What are the white spots on my cannabis leaves?
White spots are typically: powdery mildew (fuzzy white patches that spread), thrips damage (silver scratches/streaks), or light burn (top leaves only). Powdery mildew is most commonâtreat immediately with neem oil or baking soda spray. See our disease guide.
Why are my cannabis leaves curling?
Curling pattern tells you the cause: Upward curling (tacoing) = heat stress or light burn. Downward curling (clawing) = nitrogen toxicity or overwatering. Edges curling up = potassium deficiency or underwatering. Match the pattern to diagnose.