My plants are about 3 weeks old and they have all started to grow some greeny bluey kind of mold on the sides of the pots. When we cut the pot open we found that some of the mold has been growing on the outer soil as well.
They were planted quite early and I would like to save them, if at all possible.
Thats why I no longer use them. I do use the peat pellets but I know of a lot of gardeners who have had this and other issues with the peat pots. The good news is it doesnt seem to bother the plants. Be sure you break the bottom off the pots too, the roots dont push through, as advertised.
At 3 weeks old Im assuming they are under lights and given your location its probably pretty cold still. A fan would be a good idea for air circulation, but mold seems to be a given with those pots. I would transplant the soil and all into a plastic container just so I didnt have to look at the mold, but be careful to not disturb the young seedling.
The good news is your plants shouldnt be effected, at least mine never were. But, when I use those pots that exactly what happened to mine too.
The same thing happens when I use cowpots so it's not exclusive to peat. Spacing the plants a little further apart should help too. Mold needs a constantly damp atmosphere to grow. Even a little air circulation should help.
Ditto cutting the bottom of the pot when you transplant. They simply don't break down fast enough in the environment and strangle the roots. That's why I'm experimenting with cowpots and newspaper pots this year.
Same here I grow in regular nursery pots but I use them year after year. My clients save them for me. You can plant in yogurt, pudding any # of plastic containers. Just make sure you poke some holes in the bottom for drainage. Plastic Strawberry containers make great mini Green Houses, and you can just recycle them.
Usually the mold that you are speaking of is what I call a harmless water mold and does not cause any problem with your plants. This happens a lot in the greenhouse and even will appear on the outside of clay pots. The only time that mold is a real problem is when they have been kept to wet and then they may begin to rot.