Grow Journal diagnosis library
Cannabis Plant Problem Guides
These symptoms overlap. Color alone is unreliable, and environmental stress can mask nutrient problems. Misdiagnosis wastes time and can burn plants.
Nutrients, pH & feeding
- Nitrogen Toxicity in Cannabis? (Dark Green Clawing)
- Calcium Deficiency? (Rusty Spots & Weak Growth)
- Nitrogen Deficiency? (Yellowing Bottom Leaves)
- Purple/Dark Leaves? (Phosphorus Deficiency)
- Brown Crunchy Edges? (Potassium Deficiency)
- Interveinal Yellowing? (Magnesium Deficiency)
- pH Lockout? (Leaves Pale But EC Fine)
- Salt Buildup? (High EC, Burnt Tips)
- Yellow New Growth? (Sulfur Deficiency)
- Yellow New Leaves, Green Veins? (Iron Deficiency)
- Speckled New Leaves? (Manganese Deficiency)
- Twisted Small New Leaves? (Zinc Deficiency)
- Brittle New Growth? (Boron Deficiency)
- Metallic Dark/Teal Leaves? (Copper Deficiency)
- Too Much K? (Locked-out Micros)
- Burnt Tips? (Nutrient Burn)
- Too Much P? (Micronutrient Lockout)
- Chlorine/Chloramine Burn?
- Burnt Leaf Tips (Not Nutrients)?
- Molybdenum Deficiency? (Mo Deficiency)
- Ammonia Toxicity Cannabis
- Sulfur Deficiency in Cannabis Seedlings
- Iron Deficiency in Cannabis Seedlings
- Zinc Deficiency in New Cannabis Growth
- Manganese Deficiency in New Growth
- Calcium Lockout in Cannabis
- Magnesium Lockout in Cannabis
- Potassium Lockout in Cannabis
- Micronutrient Lockout in Cannabis
- Nutrient Burn in Cannabis Seedlings
- Seedling Tip Burn
- Nitrogen Toxicity in Cannabis Seedlings
- Micronutrient Toxicity in Cannabis
- Reservoir pH Swing in Cannabis
- Nitrogen Deficiency in Cannabis Seedlings
- Leaf Tip Burn After Feeding Cannabis
- Magnesium Deficiency Under LED Cannabis
- Nutrient Uptake Stalled in Cannabis
- Incorrect pH After Feeding Cannabis
- Potassium Deficiency in Cannabis Seedlings
- Iron Deficiency in New Growth Cannabis
- Boron Deficiency in Cannabis Seedlings
- Cal-Mag Deficiency Under LED Cannabis
- Lockout After pH Down Cannabis
- Lockout After Flush Cannabis
- Seedling Burnt Tips After Feed Cannabis
- Clone Tips Burning Cannabis
- Phosphorus Deficiency in Cannabis Seedlings
- Calcium Deficiency in New Growth Cannabis
- Zinc Deficiency in Cannabis Seedlings
- Copper Deficiency in New Growth Cannabis
- Nutrient Solution Too Strong Cannabis
- Magnesium Deficiency in Cannabis Seedlings
- Sulfur Deficiency in New Growth Cannabis
- Boron Deficiency in New Growth Cannabis
- Manganese Deficiency in Cannabis Seedlings
Watering, roots & media
- Coco Grower? Cal-Mag Deficiency Fast Check
- Overwatered? (Droop After Watering)
- Underwatered? (Crispy Dry Leaves)
- Roots Circling Pot? (Rootbound)
- Droopy Leaves (Not Overwatering)?
- Oxygen Deficiency in Roots? (Root Hypoxia)
- Algae on Soil? (Green Surface Growth)
- Calcium Deficiency in Hydro Cannabis
- Phosphorus Deficiency From Cold Soil
- Salt Buildup in Coco Cannabis
- High EC Soil in Cannabis
- Runoff EC Too High in Cannabis
- Overwatered Cannabis Seedlings
- Underwatered Cannabis Seedlings
- Drooping After Watering Cannabis
- Soggy Soil Around Cannabis
- Brown Roots in Hydro Cannabis
- Slimy Roots in Hydro Cannabis
- Hydro Reservoir Too Warm for Cannabis
- Drowning Roots in Cannabis
- Clone Yellowing After Rooting: What to Check First
- Slow Rooting Clones in Cannabis
- Cold Roots in Cannabis
- Hot Root Zone in Cannabis
- Iron Deficiency in Hydro Cannabis
- Sulfur Deficiency in Hydro Cannabis
- Boron Deficiency in Coco Cannabis
- Molybdenum Deficiency in Hydro Cannabis
- Nutrient Lockout in Coco Cannabis
- Nutrient Lockout in Hydro Cannabis
- pH Too Low in Soil Cannabis
- pH Too High in Soil Cannabis
- pH Too Low in Hydro Cannabis
- pH Too High in Hydro Cannabis
- EC Too High in Coco Cannabis
- Runoff pH Too Low in Cannabis
- Runoff pH Too High in Cannabis
- Root Bound Cannabis
- Waterlogged Cannabis Soil: Root Warning Signs
- Dry Pockets in Soil Cannabis
- Algae in Hydro Reservoir Cannabis
- Clone Not Rooting in Cannabis
- Seedling Falling Over After Watering in Cannabis
- Low Root Temperature in Hydro Cannabis
- Hot Soil Cannabis
- Calcium Deficiency in Soil Cannabis
- Magnesium Deficiency in Hydroponic Cannabis
- Potassium Deficiency in Hydro Cannabis
- pH Drifting in Coco Cannabis
- Runoff EC Too Low in Coco Cannabis
- Salt Crust on Soil Cannabis
- Root Zone pH Unstable in Cannabis
- Root Zone EC Unstable in Cannabis
- Compact Soil Poor Drainage in Cannabis
- Soil Not Drying Out in Cannabis
- Roots Coming Out of Pot Cannabis
- Overwatered Autoflower Cannabis
- Underwatered Flowering Cannabis
- Watering Too Frequently Cannabis
- Watering Too Much Runoff Cannabis
- Clone Yellowing Before Roots Cannabis
- Clones Rooting Too Slow Cannabis
- Phosphorus Deficiency in Hydroponic Cannabis
- Sulfur Deficiency in Coco Cannabis
- Zinc Deficiency in Hydro Cannabis
- Copper Deficiency in Hydro Cannabis
- Manganese Deficiency in Hydro Cannabis
- Nutrient Burn in Coco Cannabis
- Nutrient Burn in Hydro Cannabis
- High Runoff PPM Cannabis
- Low Runoff PPM Cannabis
- Coco Not Buffered Cannabis
- Hydro Roots Smell Bad Cannabis
- Overwatered Clones Cannabis
- Underwatered Coco Cannabis
- Clone Stunted After Rooting Cannabis
- Magnesium Deficiency in Coco Cannabis
- Sulfur Deficiency in Hydroponic Cannabis
- Iron Deficiency in Coco Cannabis
- Boron Deficiency in Hydro Cannabis
- Manganese Deficiency in Coco Cannabis
- Micronutrient Deficiency in Coco Cannabis
- Salt Lockout in Hydro Cannabis
- pH Fluctuations in Coco Cannabis
- Runoff PPM Spiking Cannabis
- Root Zone Too Dry Cannabis
- Root Zone Too Wet Cannabis
- Poor Drainage in Fabric Pot Cannabis
- Compact Coco Cannabis
- Hydro Reservoir Foaming Cannabis
- Watering Before Medium Dries Cannabis
- Watering After Dryback Too Long Cannabis
- Drooping After Heavy Watering Cannabis
- Runoff Too High Every Feed Cannabis
- Autoflower Stunted After Overwatering: Recovery Signs
- Clone Wont Root Under LED Cannabis
- Phosphorus Deficiency in Coco Cannabis
- Potassium Deficiency in Hydroponic Cannabis
- Nitrogen Deficiency in Coco Cannabis
- Iron Deficiency in Hydroponic Cannabis
- Zinc Deficiency in Coco Cannabis
- Micronutrient Deficiency in Hydro Cannabis
- pH Too Low in Coco Cannabis
- pH Too High in Coco Cannabis
- Runoff pH Swing Cannabis
- EC Swing in Hydro Cannabis
- Root Zone Salt Buildup Cannabis
- Roots Turning Tan in Hydro Cannabis
- Dry Hydrophobic Soil Cannabis
- Coco Water Channeling Cannabis
- Autoflower Yellowing After Overwatering Cannabis
- Underwatered Fabric Pot Cannabis
- Watering Small Rings Around Seedlings Cannabis
- Calcium Deficiency in Coco Cannabis
- Calcium Deficiency in Hydroponic Cannabis
- Nitrogen Deficiency in Hydroponic Cannabis
- Zinc Deficiency in Hydroponic Cannabis
- Runoff pH Swing in Coco Cannabis
- EC Swing in Coco Cannabis
- Root Zone Salt Buildup in Coco Cannabis
- Roots Turning Tan in Coco Cannabis
- Dry Hydrophobic Soil in Fabric Pot Cannabis
- Coco Water Channeling in Seedlings Cannabis
- Drooping After Every Feed in Coco Cannabis
- Autoflower Yellowing After Overwatering in Fabric Pot Cannabis
- Underwatered Fabric Pot in Late Flower Cannabis
- Watering Small Rings Around Clone Cannabis
- Seedling Stalling in Coco Cannabis
- Seedling Yellow Center in Hydro Cannabis
- Clone Pale New Growth in Coco Cannabis
- Calcium Deficiency in Seedlings Coco Cannabis
- Magnesium Deficiency in Late Flower Hydro Cannabis
- Phosphorus Deficiency in New Growth Coco Cannabis
- Potassium Deficiency in Seedlings Hydro Cannabis
- Nitrogen Deficiency in Late Flower Hydro Cannabis
- Iron Deficiency in New Growth Hydro Cannabis
- Zinc Deficiency in Seedlings Coco Cannabis
Light, heat & environment
- Heat Stress vs Deficiency? (Tacoing & Curling)
- Light Burn vs Nutrient Burn?
- Low Humidity? (High VPD Stress)
- High Humidity? (Low VPD Stress)
- White Tops? (Light Bleaching)
- Stretching Seedlings? (Light Too Weak)
- Fluffy/Larfy Buds? (Low Light/Heat/Overfeed)
- Light Leaks in Flower? (Re-Veg/Herm Risk)
- Cold Stress on Cannabis? (Low Temperature Damage)
- Cold Temperature Stress Cannabis
- Wind Burn on Cannabis? (Fan Damage)
- Temperature Fluctuations? (Temp Swings)
- Humidity Too High in Flowering? (High RH Buds)
- Humidity Too Low Seedlings Cannabis
- CO2 Deficiency? (Slow Growth in Sealed Rooms)
- Seedling Stretching After Sprout
- Humidity Too Low for Clones
- Humidity Too High in Veg Cannabis
- VPD Too High in Veg Cannabis
- VPD Too Low in Veg Cannabis
- Heat Stress in Cannabis Seedlings
- Grow Lights Too Close to Cannabis Seedlings
- Grow Lights Too Far From Cannabis Seedlings
- LED Light Stress in Cannabis
- Foxtailing From LED Light Stress
- Taco Leaves From High Heat
- Wind Stress in Cannabis Seedlings
- Nighttime Humidity Spikes in Cannabis
- Condensation on Cannabis Buds
- Purple Buds From Cold Stress
- Airy Buds From High Heat
- Buds Bleaching Under LED
- High VPD in Cannabis Seedlings
- Low VPD in Flower Cannabis
- Lights Too Close to Clone Cannabis
- Lights Too Far in Veg Cannabis
- LED Bleaching Top Cola Cannabis
- High Canopy Temperature Cannabis
- Seedlings Stretching Under LED Cannabis
- High Leaf Surface Temperature Cannabis
- Low Night Temperature Cannabis
- Humidity Swing in Grow Room Cannabis
- Leaves Limp Before Lights Off Cannabis
- Leaf Edges Tacoing Under Heat Cannabis
- High VPD in Early Flower Cannabis
- Low VPD in Clones Cannabis
- Lights Too Close in Flower Cannabis
- Lights Too Far in Early Veg Cannabis
- Seedling VPD Too Low Cannabis
- Clone Humidity Too High Cannabis
- LED Light Bleaching in Early Flower Cannabis
- Canopy Too Close to Light Cannabis
- Humidity Crash After Lights On Cannabis
- Fan Wind Burn on Top Leaves Cannabis
- Seedling Tacoing Under Heat Cannabis
- Clone Light Too Strong Cannabis
- High VPD in Late Flower Cannabis
- Low VPD in Seedlings Cannabis
- Room Too Hot Lights On Cannabis
- Room Too Cold Lights Off Cannabis
- Exhaust Too Weak in Grow Room Cannabis
- Condensation on Bud Sites Cannabis
- Seedling Tacoing Lights On Cannabis
- Clone Drooping Lights On Cannabis
- Clone Leaf Edges Curling Up Lights On Cannabis
- Clone Light Too Strong in Seedlings Tent Cannabis
- Low VPD in Late Flower Cannabis
- Room Too Cold in Seedlings Cannabis
- Exhaust Too Weak in Late Flower Cannabis
- Condensation on Bud Sites Lights Off Cannabis
- High VPD in Clone Cannabis
- Low VPD in Clone Cannabis
Pests, mold & disease
- Root Rot Early Signs (Mushy Roots, Droop)
- White Dust on Leaves? (Powdery Mildew Early Signs)
- Brown/Gray Bud Centers? (Bud Rot Early Signs)
- Tiny Flies in Soil? (Fungus Gnats)
- Spider Mites on Cannabis? (Tiny Web Spinners)
- Aphids on Cannabis? (Sap-Sucking Colonies)
- Whiteflies on Cannabis? (Flying Sap Suckers)
- Broad Mites? (Invisible Leaf Twisters)
- Damping Off? (Seedling Stem Rot)
- Spider Mites Webbing Cannabis
- Broad Mites Damage Cannabis
- Hemp Russet Mites? (Bronze Leaf Plague)
- Aphids Honeydew Cannabis
- Whiteflies Infestation Cannabis
- Caterpillars Eating Cannabis? (Leaf & Bud Worms)
- Leaf Septoria? (Yellow Leaf Spot Disease)
- Fusarium Wilt? (One-Sided Wilting Disease)
- Hop Latent Viroid? (HLVd Dudding Disease)
- Mealybugs on Cannabis? (White Fuzzy Bugs)
- Scale Insects on Cannabis? (Brown Bumps)
- Leafhoppers on Cannabis? (Jumping Bugs)
- Verticillium Wilt? (Vascular Disease)
- Seedling Stem Rot Cannabis
- Stem Rot on Cannabis? (Collar Rot)
- Pythium Root Rot? (Slimy Brown Roots)
- Tobacco Mosaic Virus? (TMV on Cannabis)
- Wilting Cannabis Plants? (Entire Plant Drooping)
- Snails or Slugs? (Holes in Outdoor Leaves)
- Seedlings Wilting After Transplant
- Mildew on Cannabis Buds
- Moldy Soil in Cannabis Pots
- Necrotic Leaf Edges on Cannabis
- Aphids on Cannabis Stems
- Fungus Gnats in Cannabis Seedlings
- Early Spider Mite Speckling on Cannabis
- Caterpillar Frass on Cannabis Buds
- Rotting Stems at the Soil Line
- Root Aphids in Cannabis
- Cannabis Clone Wilting Under a Humidity Dome
- Clone Stem Rot in Cannabis
- Powdery Mildew on Fan Leaves Cannabis
- Gray Mold Inside Cola Cannabis
- Leaf Septoria on Lower Canopy Cannabis
- Fungus Gnats in Coco Cannabis
- Spider Mites Under Leaves Cannabis
- Whiteflies Under Canopy Cannabis
- Caterpillars in Outdoor Buds Cannabis
- Powdery Mildew Spreading Fast Cannabis
- Bud Rot After Rain Outdoor Cannabis
- Septoria Yellowing Lower Leaves Cannabis
- Spider Mites Webbing in Late Flower Cannabis
- Fungus Gnats in Overwatered Soil Cannabis
- Aphids Under Fan Leaves Cannabis
- Powdery Mildew Returning Cannabis
- Bud Rot Inside Dense Colas Cannabis
- Leaf Septoria Spreading Cannabis
- Spider Mites Speckled Fan Leaves Cannabis
- Fungus Gnats on Young Plants Cannabis
- Aphids on New Growth Cannabis
- Whiteflies Flying When Disturbed Cannabis
- Gray Mold After Humidity Spike Cannabis
- Spider Mites in Lower Canopy Cannabis
- Fungus Gnats in Seed Starting Mix Cannabis
- Aphids Clustered on Stems Cannabis
- Gray Mold in Lower Canopy Cannabis
- Spider Mites After Heat Spike Cannabis
- Fungus Gnats After Overwatering Cannabis
- Aphids Under Leaves Cannabis
Flowering & plant development
- Foxtailing? (Heat/Light Stress vs Genetics)
- Pistils Browning Early?
- Bananas/Nanners Appearing? (Hermaphrodite)
- Single-Blade Leaves in Buds? (Re-Veg)
- Hermaphrodite Cannabis? (Male Flowers on Females)
- Yellowing During Flowering? (Early Fade)
- Small Buds & Low Yield? (Poor Bud Development)
- Buds Not Fattening Up? (Thin Buds)
- Nitrogen Deficiency in Flowering? (N Def Flower)
- Potassium Deficiency in Flowering? (K Def Flower)
- Male Plants vs Hermies? (Identifying Males)
- Revegetation? (Flowering Back to Veg)
- Slow Flowering? (Buds Not Developing)
- Premature Flowering Outdoor? (Early Flower)
- Calcium Deficiency During Flowering
- Magnesium Deficiency During Flowering
- Phosphorus Deficiency During Flowering
- Boron Deficiency During Flowering
- Copper Deficiency During Flowering
- Potassium Deficiency in Late Flower
- Nutrient Lockout During Flowering
- Nutrient Burn in Autoflower Cannabis
- Low Airflow During Flowering
- Leaves Curling Under in Flower
- Leaves Fading Too Early in Flower
- Airy Buds From Low PPFD
- Buds Foxtailing in Late Flower
- Brown Pistils Too Early in Flower
- Leaves Turning Red or Purple in Flower
- Calcium Deficiency in Autoflower Cannabis
- Magnesium Deficiency in Autoflower Cannabis
- Phosphorus Deficiency in Autoflower Cannabis
- Potassium Deficiency in Autoflower Cannabis
- Nutrient Burn in Late Flower Cannabis
- Zinc Deficiency During Flower Cannabis
- Transplant Shock in Autoflower Cannabis
- Nitrogen Toxicity in Flowering Cannabis
- Calcium Deficiency in Early Flower Cannabis
- Magnesium Deficiency in Late Flower Cannabis
- Potassium Deficiency in Early Flower Cannabis
- Calcium Deficiency in Late Flower Cannabis
- PPFD Too Low in Early Flower Cannabis
- Phosphorus Deficiency in Late Flower Cannabis
- Room Too Hot in Late Flower Cannabis
- PPFD Too High in Late Flower Cannabis
Other plant symptoms
- Cannabis Leaves Curling Down? (Clawing Explained)
- Brown Spots on Cannabis Leaves? (Rule Out These Causes)
- Silver Streaks? (Thrips Damage)
- Purple Stems? (Cold, Genetics, or Stress)
- Slow/Wilt After Transplant?
- Leaf Miners on Cannabis? (Tunnel-Making Larvae)
- Slow Vegetative Growth? (Plant Not Growing)
- Alternaria Leaf Spot? (Target Spot)
- Stunted Growth? (Plant Not Getting Bigger)
- Leaves Turning Yellow Overnight? (Sudden Yellowing)
- Crispy Leaves? (Dry Brittle Foliage)
- Curling Leaves Upward? (Leaf Cupping)
- Twisted New Growth? (Deformed Leaves)
- Leaf Edges Curling Up Cannabis
- Seed Shell Stuck? (Helmet Head Seedling)
- Transplant Stress in Cannabis Seedlings
- Clone Drooping After Transplant
- Clone Leaves Curling Down
- Purple Clone Stems
- Seedling Leaves Yellowing
- Seedling Leaves Curling
- Seedling Leaves Twisting
- Cotyledons Turning Yellow Fast
- Cannabis Seedling Growing Too Slow
- PPFD Too High for Cannabis
- PPFD Too Low for Cannabis
- Canoeing Leaves From LED Stress
- White Powder on Cannabis Leaves
- Rust Spots on Cannabis Leaves
- Yellow Spots on Cannabis Leaves
- Black Spots on Cannabis Leaves
- Cannabis Leaves Praying Too Much
- Leaves Curling Down in Veg
- Leaves Tacoing Under LEDs
- Fan Leaves Yellowing From the Bottom Up
- Yellow New Growth at the Top Canopy
- Cannabis Calyxes Not Swelling
- Thrips Silver Streaks on Cannabis
- Gnawed Leaf Edges on Outdoor Cannabis
- Grasshoppers Eating Cannabis
- Earwigs on Cannabis: Identify Damage Before Treating
- Ants on Cannabis Plants
- Cannabis Stem Splitting: Mechanical Crack or Disease?
- Hollow Stems in Cannabis
- Weak Stems in Cannabis Seedlings
- Brittle Stems in Cannabis
- Red Petioles From Cannabis Stress
- Calcium Excess in Cannabis
- Phosphorus Excess in Cannabis
- EC Too Low in Cannabis
- Reservoir EC Swing in Cannabis
- Clone Leaves Curling Up in Cannabis
- Clone Leaves Drooping in Cannabis
- Clone Stems Turning Purple in Cannabis
- Seedling Leaves Pointing Up in Cannabis
- Seedling Leaves Curling Down in Cannabis
- Seedling Stem Too Thin in Cannabis
- Seedlings Growing Unevenly in Cannabis
- Excessive Defoliation Stress in Cannabis
- Dark Green Clawing Leaves in Cannabis
- Cal-Mag Overuse in Cannabis
- Flush Shock in Cannabis
- Drooping After Transplant Cannabis
- Seedling Leaves Tacoing Cannabis
- Seedling Cotyledons Yellowing Early Cannabis
- Seedling First True Leaves Twisted Cannabis
- Seedlings Growing Too Slow Cannabis
- Leaf Canoeing Under LED Cannabis
- Large Temperature Swing Cannabis
- Stagnant Air in Grow Room Cannabis
- Too Much Direct Fan on Cannabis
- LED Hotspot on Top Leaves Cannabis
- Thrips on Seedlings Cannabis
- Excess Nitrogen Dark Leaves Cannabis
- Drooping Leaves After Feed Cannabis
- Medium Staying Wet Too Long Cannabis
- Seedling Purple Stem Stress Cannabis
- Seedling Drooping Under LED Cannabis
- Seedling Edges Curling Up Cannabis
- Seedling Cotyledons Browning Cannabis
- Clone Leaves Yellowing Under Dome Cannabis
- Clone Medium Too Wet: Root Warning Signs
- Clone Leaf Twist Cannabis
- Top Leaves Praying Too Hard Cannabis
- Grow Room Too Dry Cannabis
- Grow Room Too Humid Cannabis
- Thrips Damage on New Growth Cannabis
- Seedling Helmet Head Wont Open Cannabis
- Seedling First Leaves Yellowing Cannabis
- Seedling Curling After Transplant Cannabis
- Seedling Red Stem LED Stress Cannabis
- Clone Leaves Pale Green Cannabis
- Clone Stem Browning Cannabis
- Cannabis Clone Tacoing: Heat, Light, or Air?
- Grow Room Hotspots Cannabis
- Nighttime Temperature Drop Too Big Cannabis
- Low Air Exchange in Grow Tent Cannabis
- Thrips Black Specks on Leaves Cannabis
- Fabric Pot Not Drying Evenly Cannabis
- Drooping Every Morning Cannabis
- Drooping After Every Feed Cannabis
- Seedling Stalling After Sprout Cannabis
- Seedling Cotyledons Not Opening Cannabis
- Seedling Yellow Center New Growth Cannabis
- Seedling Praying Too Hard Cannabis
- Clone Drooping After Dome Removed Cannabis
- Clone Pale New Growth Cannabis
- Clone Stem Softening Cannabis
- Clone Leaf Edges Curling Up Cannabis
- PPFD Too High in Seedlings Cannabis
- White Powder Returning on Leaves Cannabis
- Thrips Damage on Fan Leaves Cannabis
- Shore Flies in Grow Room Cannabis
- Drooping Every Morning in Seedlings Cannabis
- Seedling Cotyledons Stuck Cannabis
- Seedling Praying After Feed Cannabis
- Clone Stem Softening After Feed Cannabis
- PPFD Too High in Clone Cannabis
- PPFD Too Low in Seedlings Cannabis
- White Powder Returning After Spray Cannabis
- PPFD Too Low in Clone Cannabis
- Shore Flies Under Pots Cannabis