Troubleshooting
Part of the free Stevie Weedseed grow guide. No paywall, no account, written by a working grower.
Overwatering
Symptoms: Drooping leaves (they look heavy and puffy, not thin and wilted), slow growth, yellowing, soil staying wet for days.
Fix: Let the soil dry out. Lift the pot. Heavy means wait. Add perlite to your next soil mix for better drainage. Make sure pots have drainage holes.
Fix: Let the soil dry out. Lift the pot. Heavy means wait. Add perlite to your next soil mix for better drainage. Make sure pots have drainage holes.
Nutrient Deficiencies
Nitrogen (N): Yellow leaves starting from the bottom up. Most common in flower when N is reduced too quickly.
Calcium: Brown spots on middle-age leaves. Very common in coco coir and RO water grows.
Magnesium: Yellowing between leaf veins while veins stay green (interveinal chlorosis).
Potassium: Brown or burnt leaf margins (edges).
Most deficiencies are actually pH lockout. The nutrients are in the soil but the plant cannot access them. Check pH first, always.
pH & Nutrient Lockout Chart →
Calcium: Brown spots on middle-age leaves. Very common in coco coir and RO water grows.
Magnesium: Yellowing between leaf veins while veins stay green (interveinal chlorosis).
Potassium: Brown or burnt leaf margins (edges).
Most deficiencies are actually pH lockout. The nutrients are in the soil but the plant cannot access them. Check pH first, always.
pH & Nutrient Lockout Chart →
Nutrient Burn
Symptoms: Brown or burnt leaf tips, very dark green leaves, leaves clawing downward.
Fix: Flush the soil with plain pH'd water (3x pot volume). Resume feeding at 50% strength. Always start nutrients lighter than the bottle says.
Fix: Flush the soil with plain pH'd water (3x pot volume). Resume feeding at 50% strength. Always start nutrients lighter than the bottle says.
Light Stress
Symptoms: Leaves curling upward ("tacoing"), bleached or white tops, burnt leaf edges.
Fix: Raise the light 6 inches. Reduce intensity if dimmable. Check PPFD with a meter or app. Most plants max out around 800 PPFD without CO2.
Light Requirements Reference →
Fix: Raise the light 6 inches. Reduce intensity if dimmable. Check PPFD with a meter or app. Most plants max out around 800 PPFD without CO2.
Light Requirements Reference →
Pests
Spider Mites: Tiny dots on leaves, fine webbing. Neem oil every 3 days for 2 weeks.
Fungus Gnats: Small flies near the soil. Let soil dry completely between waterings plus yellow sticky traps.
Aphids: Green or black clusters on stems. Neem oil, and introduce ladybugs outdoors.
Thrips: Silver streaks on leaves. Spinosad spray is most effective.
Prevention beats treatment every time: clean grow space, inspect plants weekly, quarantine new plants.
Fungus Gnats: Small flies near the soil. Let soil dry completely between waterings plus yellow sticky traps.
Aphids: Green or black clusters on stems. Neem oil, and introduce ladybugs outdoors.
Thrips: Silver streaks on leaves. Spinosad spray is most effective.
Prevention beats treatment every time: clean grow space, inspect plants weekly, quarantine new plants.
Mold & Mildew
Powdery Mildew: White powder on leaves. Improve airflow immediately. Spray 1 tbsp baking soda plus 1 tsp dish soap in 1 gallon water. Neem oil prevents recurrence.
Bud Rot: Gray or brown mold inside buds. Remove affected buds immediately plus 2 inches of surrounding material. Lower humidity to 40%. Increase airflow. It cannot be reversed, only contained.
Bud Rot: Gray or brown mold inside buds. Remove affected buds immediately plus 2 inches of surrounding material. Lower humidity to 40%. Increase airflow. It cannot be reversed, only contained.