Mold on seedling pots

[Annwfn]

I am growing lots of seeds at the moment and as I have a limited number of windowsills I treated myself to some propagators with lights. They seem to be working great with the plastic inserts or with other plastic pots, but I have some seedlings in compostable pots and they are developing mould. I have the vents open and the sides are not covered in condensation so it shouldn't be to damp, but all the pots have got mould on them. Any advice? Should I only use these types of pot in uncovered trays?

[Westi]

I got this on mine when I used them & was told it was part of the compostable attributes & you should just plant one seed in them which when ready you plant out intact with just a good soaking before to help it compost. I gave up on them as it was a yearly expense when the plastic pots can be washed & used for years.

[Primrose]

I,m inclined to agree with Westi. These pots are open to mould appearing which isn't easy to remove althiugh the outer surfaces of the pot could be wiped clean with a sheet of kitxhen paper at the risk of causing the surface of the pot to break up. I think it would take a lot of continual draughts and fresh air to prevent this happening as the pots have to be watered regularly. Every watering risks more mould or plot surface breakdown. They,re really quite flimsy.

I used these pots one season when they were heavily advertised as being "the latest environmentally friendly thing" and found many of them simply broke up before the seedling was ready to plant out. Wouldn,t use them again.

As Westi says, plastic pots are not the purge they,re alleged to be. Many of mine have been washed out, stored and reused for 30+ years and still have plenty of life left in them because they,re only in use for about 3 months before everything is planted out.