Damping Off - A Seedling Killer!

A cucumber seedling has withered and died overnight due to damping off disease.

Adequate light reduces the chances of an infection.

A heating mat keeps roots warm.

Seedlings grown in peat pellets are prone to damping off as the peat absorbs too much water and stays wet too long.

Select a sterile potting soil designed for seeds.

Once seeds germinate they are vulnerable to the fungus Damping Off. Seedling stems become thin and thread-like, then they fall over and die. It is a quick death.

• Soil: Use a free draining sterile potting mix for seedlings. Add extra sand or vermiculite if it’s too peaty and doesn’t drain quickly.
• Avoid peat pellets: Made from pure peat surrounded by netting, they absorb too much water.
• Cleanliness: Sterilize any reused pots or cell packs in bleach and water.
• Drainage: Good drainage is essential so pots should have drainage holes – don’t cover them with anything.
• Monitor Moisture: Avoid keeping the soil too wet: check with your fingers before adding more water.
• Avoid Cold Water: Room temperature water is best from 20 to 22°C (68 to 72°F).
• Warm Roots: Use a propagating heated mat available at home hardware stores and garden centres.
• Warm Conditions: Room temperature should be at least 15.5 to 21.1°C (60-70°F)  
• Adequate Light: Seedlings should receive 12 to 16 hours of light per day.
• Avoid Overcrowding: Don’t sow seeds too thickly; follow packet instructions for seed spacing.
• Control: There are fungicides on the market to prevent damp off, however, I like to water and mist seedlings with chamomile tea as it contains anti-fungal properties. Allow it to cool to room temperature before applying.  ​

Thin overcrowded seedlings to allow more air movement below and above the soil.

Lovely healthy cucumber seedlings!