When Nothing Matches: The Full Plant-Problems Picture List
Plant looks wrong and nothing matches? The full picture list of cannabis problems — compare yours against real photos and find the guide that fixes it.
Grow problems
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Deficiencies
Dark, Purple, Spotty and Slow — That's Phosphorus
Dark dull leaves, purple stems, bronze blotches and stalled growth? That's phosphorus — not harmless purpling. The tells and the fix.
Pale New Growth? It Says Iron, But It Usually Means pH
Newest top leaves pale yellow with bright green veins? That's iron — and nine times out of ten it's actually pH. Here's how to tell, and the fix.
Purple Stems: The Most Diagnosed Non-Problem in Growing
Purple or red stems on an otherwise healthy plant are usually genetics or cool nights — not trouble. When to leave it alone and when to look closer.
Rusty Spots on Your Leaves? That's Probably Cal-Mag
Rusty speckling on your leaves, growing in coco or with RO water? That's a Cal-Mag shortage. What it looks like, why it happens, and the fix.
Scorched Edges Aren't Always Burn — Meet Potassium
Brown scorched edges on older leaves while the middle stays green? That's potassium, not nute burn. How to tell them apart and fix it.
The Claw: When Dark Green Means You've Overdone It
Dark glossy leaves clawing down like talons? That's nitrogen toxicity — overfed, not sick. Why it happens and how to bring her back.
Yellow Leaves, Green Veins — Reading a Magnesium Deficiency
Leaves yellowing between the veins while the veins stay green? Classic magnesium. Why pH is usually behind it, and how to fix it properly.
Roots & water
Root Rot: The Trouble You Smell Before You See
Brown slimy roots, swampy smell, drooping that water won't fix? Root rot — in hydro or soil. How to spot it, stop it, and keep it gone.
Root-Bound: The Plant That Outgrew Her Flat
Water running straight through, growth crawling, roots circling the pot? She's root-bound. How to tell, and how to pot up without drama.
Flower & buds
Foxtailing: When Your Buds Start Building Towers
Buds throwing spindly towers or going airy late in flower? Foxtailing is usually heat or light stress at the canopy. How to read it and fix it.
Other
Aphids: There's Never Just the One
Soft green clusters on the stems and new growth, sticky leaves below? Aphids, and they breed fast. How to blast them off, treat, and bring in predators.
Bud Rot: The One That Costs the Most
Grey fuzz inside the bud, a mushy brown core, one wilted sugar leaf? Bud rot — botrytis. How to cut it out, dry the space out, and stop it spreading fast.
Caterpillars: Something's Been Eating Her
Ragged holes in the leaves and little dark grains on the buds? Caterpillars are eating her. How to pick them off, check daily, and treat with a BT spray.
Cold Stress: She's Not Dying, She's Sulking
Plant gone sluggish and droopy when the lights are off? That's cold stress, not disease. How to read night temps and warm her back up without cooking her.
Environmental Monitoring: Stop Flying Blind
Guessing your tent's heat and humidity by feel? Feel lies. How a cheap thermo-hygrometer at canopy height catches half your problems before they show.
Fungus Gnats: Overwatering's Best Mate
Little black flies skipping off the soil when you water? Fungus gnats — overwatering's best mate. How to dry the surface, trap them, and treat the larvae.
Heat Stress: She's on a Beach With No Shade
Leaves curling up like a taco and wilting under the light? That's heat stress. How to read canopy temperature and cool her down before damage sticks.
High Humidity: The Quiet One That Rots Your Best Cola
Damp tent and worried about mould? High humidity invites mildew and bud rot and slows her drinking. The RH targets and how to pull the damp air right down.
Light Burn: The Tops Are Sunburnt
Bleached white or crispy tops under the light, lower buds grand? Light or heat burn — too close, too hot. How to raise the light, cool the tops, grow out clean.
Light Leak: She Panicked in the Dark
Pollen sacs, nanners or seeds turning up in your buds? A light leak in her dark hours stressed her into hermie. How to make the tent light-tight and act fast.
Light Stress: Too Much of a Good Thing, Too Close
Top leaves bleaching pale and tacoing near the lamp? The light's too close or too strong. How to read light stress and raise her off the burn before it sticks.
Low Humidity: When the Air Is Drinking Her Dry
Tips crisping and she's drinking fast in dry air? That's low humidity, not a deficiency. The RH targets and how to bring the damp back without inviting mould.
Not Enough Light: She's Reaching for the Switch in the Dark
Long gaps between leaves and she's reaching for the lamp? That's too little light. How to read the stretch and get her enough intensity before she goes to seed.
Nutrient Burn: The Bottles Were Too Tempting
Brown crispy tips curling in, pH and feed already dialled? That's nutrient burn — you're feeding too hard. How to back off and grow out clean.
Nutrient Deficiency: Read the Plant Before You Reach for the Bottle
Yellowing leaves and not sure which nutrient? Read where it starts on the plant first. The diagnostic order that tells deficiency from lockout before you feed.
Overwatering: When Helping Too Hard Drowns Her
Plant drooping worst right after a drink? That's overwatering, not thirst — the roots are drowning. How to spot it and water by weight instead.
pH Lockout: The One That Fools Everyone
Feeding right but she's still showing deficiencies? Wrong pH locks nutrients out, so a well-fed plant starves. Get a pen, fix pH, watch colour return.
Powdery Mildew: The White Dust That Spreads When You Tidy It
White flour-looking dust on the leaves? Powdery mildew — a damp-air problem, not a dirty plant. How to drop humidity, move air, and stop it reaching the buds.
Spider Mites: The Dot You Should Have Looked At
Pale speckling on leaves and fine webbing underneath? Spider mites, and they breed fast. How to isolate, treat the eggs, and stop them coming back.
Thrips: The Damage People Feed Instead of Treat
Silvery-bronze streaks, pale speckling and tiny black specks on top of the leaves? Thrips, not a deficiency. How to trap, treat both sides, and break the cycle.
Underwatering: When She's Just Plain Thirsty
Leaves gone limp and a drink brings her right back? That's underwatering, not drowning. How to read a thirsty plant and water her properly before she crisps.