[Kathie]

I have had problems over the last couple of years with a white then green coloured fuzz appearing a few weeks after sowing seeds in pots, some have been kept in a polytunnel and some on the indoors sills.  Would it help to put vermiculite on top of the potting compost or would it be better to follow instructions and mix the two together?

[Kleftiwallah]

I think the white 'stuff' are mineral salts leaching out of your soil/compost.  The green may be moss starting to grow.  A layer of vermiculite would be beneficial.

Cheers,   Tony.

[Kathie]

Thanks so much for that Tony, I really thought everything was starting to go mouldy, like our house !! LOL