Seed cells have surface mold

Setting out vegetable seeds indoors for the first time. My first two Jiffy trays have developed a gray mold on the surface of the soil. (A bit surprised as I used Ferry-Morse organic seeding soil mix.) The plants (chives, onions, and parsley) appear to be doing alright.

The trays have been without tops for two weeks and sitting in a sunny east window the entire time.

Should I worry about the mold? If so, what can I do about it?

Yuck. I would try spritzing the entire surface with a mix of 1 part hydrogen peroxide to 9 parts water to try and get the mold under control. Sounds like something contaminated them for sure. I'd be all in a tizzy. If the mold is too much, I'd try scraping the surface away and tossing it, then watering with the peroxide mix. I am not an expert though, that's just what I'd try here.

The mold has nothing to do with the seeding mix you use. It is adventitious mold from airborne spores that are everywhere and in every breath we take. If it really bothers you, you can scrape it from the surface, but if your plants have emerged and doing fine, I wouldn't bother. While this is adventitious mold and shouldn't affect your plants, it is a symptom of overwatering. I would let the potting mix dry down a little more than you have been between watering and only water from the bottom, do not add any water or spray any water on the surface. Watering from the top doesn't always penetrate the whole soil profile and can promote a stratification of moisture with the top wet and the bottom of the profile becoming hydrophobic. Watering from the top can cause a very shallow root system to form whereas bottom watering will force the roots deeper as the cells dry down and promote development of a better root system.

I let my cell packs really dry down on the surface almost to the point of slight wilting and then put them into a tray of water and let them soak until you just start to see a darkening of the surface. Then remove them and let them drain for 10-15 minutes and put them back into their original trays.

Tried the hydrogen peroxide spray tonight when I got home from work. Mold disappeared to the naked eye and the seedlings didn't start screaming in agony. Hopefully that has done the trick. I'm also going to let things dry out some.
Thanks Keyi and trc65.

I agree 100% with tr65. always bottom water the babies. Annette