Root ProblemsUrgent — act today
Root Rot in Cannabis Plants
Root rot is a fast-moving, plant-killing disease caused by Pythium or similar oomycetes. Caught early, it's recoverable. Caught late, the plant dies within days.
What it looks like
- ●Droopy, wilting leaves that don't perk up after watering
- ●Yellowing across the whole plant at once
- ●Roots: slimy, brown/tan, fall apart when touched (healthy roots are white and firm)
- ●Swampy, sulfur-like smell from soil or reservoir
Quick diagnostic checks
1If you smell anything sulfuric or swampy from the pot, act TODAY
2Fabric pots and good aeration prevent 90% of root rot
3Beneficial microbes are cheap insurance
Causes ranked by likelihood
1. Overwatering in soil
Most commonSigns
- ●Soil stays wet for 5+ days
- ●No drainage holes or poor drainage
- ●Cold soil temperatures
Fix
- ✓Stop watering immediately — let soil dry out
- ✓Add drainage holes or switch to fabric pots
- ✓Water deeply but infrequently — roots need oxygen
2. Warm reservoir in hydro
Most commonSigns
- ●Reservoir temp above 72°F
- ●DWC/hydro setup
- ●Often appears after a warm spell
Fix
- ✓Get reservoir below 68°F with a chiller or frozen bottles
- ✓Dose H2O2 (3% hydrogen peroxide) at 1 ml/L to kill pathogens (short-term only)
- ✓Long-term fix: add beneficial microbes (Hydroguard, Great White)
Recommended products
Hydroguard Root Inoculant
Beneficial Bacillus bacteria — outcompetes Pythium
3. Compacted soil with no oxygen
CommonSigns
- ●Heavy clay-like soil
- ●No perlite or amendment
Fix
- ✓Transplant to a well-draining mix (30-40% perlite for cannabis)
- ✓If transplant isn't possible, poke aeration holes in soil with a chopstick
⚠️When to worry
Always. Root rot can kill a plant in 3-5 days once it takes hold. Act at the first sign of unexplained wilting that doesn't respond to water.
Gear that prevents this problem
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