Mould on top of seed trays

Question ...

I'm trying to germinate seeds in my house but I keep getting a layer of white mould on the top of my compost - does this signify my house is too cold, or I'm keeping them too damp or is this perfectly normal?

Answer ...

It is very common to get a haze of mould growing on the top of potting compost. It is usually caused by the break down of organic matter in the potting mix.

If the seeds are germinating successfully then it is not a problem. If your seeds are not germinating or die soon afterwards, then it is likely that 'damping off' fungus is present. Try the following organic prevention and control methods:

  • Pots and trays are scrubbed clean before sowing seed.
  • Drainage is good – waterlogged plants are more prone to pest and disease attack.
  • Do not overcrowd seedlings – good ventilation is essential to reduce humidity, which will encourage the disease.

If you would like further advice on your organic growing, why not become a member of Garden Organic? It costs as little as £2.75 a month, and not only gives you full access to our advisory service, but also free or discounted entrance to many gardens across the UK. Call 02476 308210 or email