Root rot (pythium)

Roots that turn brown, slimy and smelly, usually from too much water, too little oxygen or warm solution. Fix the root zone first, then help new roots grow.

Symptoms

• Brown, slimy, smelly roots instead of firm white ones; the outer layer may slough off.
• Wilting even though the medium is wet or the plant is in solution.
• Yellowing, slow growth and leaves that look hungry despite feeding.
• A bad smell from the reservoir or medium.

Quick checks

• Look at the roots: healthy roots are white or cream and firm.
• Check the solution temperature (aim for about 18–21 °C).
• Check air stones and pumps are working.
• Lift test in soil or coco: is it still heavy days after watering?

How to fix it

1. 1
   Environment

   Fix the root zone first

   Soil and coco: let the medium dry back and water less often, making sure containers drain freely. Hydro: keep solution at about 18–21 °C (under 24 °C), with strong aeration and an opaque, lightproof reservoir.

2. 2
   Physical

   Clean and replace

   Hydro: change the solution, clean and disinfect the reservoir and system, and trim away dead, mushy roots with clean snips. Remove badly affected plants and their medium so it doesn't spread.

3. 3
   Support

   Help new roots grow

   Once the cause is fixed, Ultra Zyme can help break down dead root matter, and Root Shoot is designed to support new root growth and a healthy root zone. Keep Stress in to help the plant cope with the stress.

Likely causes

• Over-watering and poor drainage, so roots sit in water without air.
• Hydro solution too warm (above about 24 °C), which holds less oxygen.
• Weak aeration in hydro; light getting into the reservoir.
• Dirty equipment or reused medium carrying disease.

What to avoid

• Don't keep watering a wilting plant in wet medium.
• Don't let the reservoir run warm or let light into it.
• Don't pour household disinfectants into the root zone.
• Don't reuse medium from a plant that had root rot.

Prevention

• Water by weight (lift test) and use free-draining containers.
• Keep hydro solution cool and well oxygenated; change it about weekly.
• Clean everything between runs and use fresh medium.

Monkey products that can help

Ultra Zyme

Enzymes that can help break down dead root matter in the root zone, used across the whole cycle.

2–3 ml per litre (20–30 ml per 10 L) across the whole cycle, in hydro, coco or soil.

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Root Shoot

Designed to build bigger root systems and support a healthy root zone, helping reduce the risk of disease.

Follow the feed chart: 2 ml per 10 L in growth weeks 1–2, then 3 ml per 10 L from growth week 3 to flower week 5.

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Stress

Monkey say silicon helps the plant manage abiotic stresses such as over-watering. Support only.

2 ml per 10 L every week. Always add it to the water first and mix thoroughly before adding anything else.

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Products support a healthy plant. They don't replace fixing the cause.

When to get help

If roots stay brown and slimy after you've corrected temperature, oxygen and watering, or several plants are affected, email info@monkeynutrients.co.uk with photos of the roots and reservoir.

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