Could overwatering in soil be causing root rot?

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

Could warm reservoir in hydro be causing root rot?

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)

Could compacted soil with no oxygen be causing root rot?

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

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 common

Signs

●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 common

Signs

●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)

3. Compacted soil with no oxygen

Common

Signs

●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.

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Root Rot in Cannabis Plants

What it looks like

Quick diagnostic checks

Causes ranked by likelihood

1. Overwatering in soil

2. Warm reservoir in hydro

3. Compacted soil with no oxygen

⚠️When to worry

Not sure what you're looking at?

Related problems

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