I don't re-use any of my soil I've used before. Could have picked up something in what you've had it stored or wasn't able to get enough air perhaps? Has it stayed moist the whole time or was it aerated fine?

I'd try some fresh soil if it were me. But there are a few others around here that could probably give you a bit better advice since this is only my second or third year of really starting from seeds.

If you do change it out though, be sure to wash the trays out pretty well before putting more back in it. Hope someone with more experience could chime in for ya though!

oh no I didn't explain it well I mean left over in the soil bag I bough too much and so I had some soil left in the bag that wasn't used for planting.

Does the mini green house have any air vents? If not then you would need to take the lid off 30 min or so, each day, then place it back on. After doing this several times the soil may dry just use a spray bottle to dampen the soil. That should keep the mold away.

Mark

This post was edited by habjolokia on Tue, Mar 12, 13 at 22:58

I have tried those mini greenhouse setups repeatedly. Some had tons of vents, some had none, all had the same results. Mold. If its effective enough to keep the warm air in, it will grow mold, I have not found any exceptions to that fact.

My advice would be to throw the cover out, or use it as a drip tray for pots. Should never be placed over actual soil.

In the mean time, spray what you've got down in hydrogen peroxide. That should kill the mold without harming your seeds/seedlings.

You have to sterilize that soil if you're going to use it to sow seeds. Get it moist and then put it in the oven on something like 160 C for 20 minutes or so. Each time you opened the bag fungus spores flew in, and now they have good conditions to grow. It would be best if you got a small package of soil meant specifically for sowing, because that will already be sterile, and used leftover soil for later transplanting.
Now you can sprinkle cinnamon around your seedlings, or spray them with h2o2 or a fungicide to keep them alive. Seeds are harder to rescue if the mould likes them...
I haven't had a problem with my dome, buti try to keep everything very clean and i don't use soil mixes...

FWIW, I'm a first-time grower. I used a mini green house and seed starting soil to germinate. It got pretty damp in there, and a few of the cells also developed a little bit of mold. I simply picked it off with my fingers, aired out the green house to reduce humidity, and put the lid back on. My germination was very successful (90+% germination rate), and I've had no adverse effects later.

thanks for all the advice I will try the peroxide and picking off the mold I see these are my first seeds so I hope they are ok

I didn't see anyone mention this yet, so I will, just in case. The top is supposed to be removed as soon as the seedlings begin emerging from the soil. If it is taking a while for things to come up, taking the top off for 10 minutes-1/2 an hour every day will help increase air circulation so the mold doesn't start forming. Using bottom heat to help speed germination helps avoid the long waiting times that lead to needing venting. But chosing the proper heat source can be tricky. I hear ovens set on low can be risky and I almost dried out my seeds by not realizing how warm the top of the cable box was. Cheers and good luck!

i'm with Edyminion, scrap the covers they are nothing but trouble.. I don't use covers but i had the same thing happen this year with a bag of miracle grow potting soil i bought at family dollar. It was all dried out, obviously last years leftovers they are still selling. Anyway, like ed said, peroxide will take care of it. John