Growing in biodegradible pots - mold on the side

Hi,

I am experimmenting with growing in biodegradible wood-pulp pots (similar to peat pots).  

Mid-winter here in New Zealand and I have them in my hot water cupboard for warmth with grow lights.
White mold is growing on the side.  I have read this can also be an issue with newspaper pots.

A fan is recommended to stop mold, but I don't see how air circulation alone will help unless you also have a filter to filter out spores or are exchanging the air with the outside to decrease mold fruiting more spores inside.
It could dry off the surface of the pots, but you wouldn't want this to happen.  I am having problems with this with the frost-hardy pots outside and the plants are wilting.

I use an organic compost that claims to be bacteria and fungi rich.

I don't understand the mechanism, but air circulation does seem to help a lot in reducing the white mold.

Making sure the pots aren't touching each other, also seems to help, but that is probably the same mechanism - better airflow if pots don't touch.

I also only water the top of the soil when it's a bit dry, and not enough for water to leak out the bottom, during the germination period and the early growth. I only water from the bottom when they're close to going into the garden and I want their roots to be going deep.

I'm using paper pots and live in a mold rich environment.

I had the same issue with jiffy pots indoors last winter. The fan thing does actually work, even a small USB one on low pointed at the trays. I think it stops the surface moisture sitting long enough for spores to take hold. The other thing that helped was letting the pot surface dry out a bit between waterings rather than keeping them constantly damp. Once the seedlings were big enough to go outside the mold disappeared on its own anyway.

I agree with the fan for air circulation.

That mold doesn't harm the plants just signals a problem with humidity and air circulation.

Jay Angler wrote: I also only water the top of the soil when it's a bit dry, and not enough for water to leak out the bottom, during the germination period and the early growth. I only water from the bottom when they're close to going into the garden and I want their roots to be going deep.

I follow the same style of watering with great results. I have been utilizing Cowpots for biodegradable containers the past few years and haven't noticed much mold/fungi development with my watering. I'm of the opinion that a little mold doesn't hurt for my processes.