Seed starting in basement; when to take the tray lids off?

[mw44118]

I've got four trays of little peat pots, with various seedlings inside, all about two weeks old.

I keep the trays full with about a half-inch of water at the bottom, and with the lids on, the soil stays very moist and the seedlings like it.

Would it harm my plants if I keep the lid on for a long time?

I'm worried the trays and the plants will dry out if I take the lids off.

[GardenJester]

I think the rule is as soon as the first seedling emerges, you should crack the dome, and put light on it. when all the seedling have emerged, you should remove the dome. Too much time under the dome after germination might make the seedlings leggy and weak.

[lj in ny]

You also don't want to keep the moisture level too high or run the risk of damping off. I don't keep standing water in my trays, I use newspaper pots and once I see the seedling emerge I move it to another tray under some lights. I mist the seedlings with chammomile tea (to prevent damping off) and have a fan on them for about 3 hours a day. I check them about 2-3 times a day to see if they need water.

[gixxerific]

Yes take the lid off as soon as you see green and put them under lights or a window (south facing is the best) whichever you have.

You could try to add chamomile tea even cinnamon to the water a little trick I learned from Rainbowgardener who is a regular on this forum. This seems to help help the fungus "damping off" away from your seedlings. Be careful with too much cinnamon though is contains a volatile oil which is the anti fungal part of it that may burn your plant.

[TZ -OH6]

I never use domes. High humidity and high water content of the soil inhibits root growth. The plants don't get water stressed so they don't grow strong roots. Peat pellets tend to dry out quickly so a cover is useful until the seeds germinate, but then can be removed. The whole peat pellet, dome thing is a marketing gimmick, although your hands stay a little cleaner than when dealing with pots and mix. Unlike peat pellets (many times), small cell flats or plastic pots will retain moisture long enough for most seeds to germinate, then you just have to water them when they start to get dry. The potting mix is usualy more nutritious for the plants as well and you need it for potting up later anyway.


When I do tissue culture techniques, and plants are grown in closed sterile flasks, the way to harden them off once they come out of the flasks is to remove the covering until the plants begin to wilt and then cover them up again, repeat the next day. Once the plants do not wilt they can stay out the whole time. You can also partialy remove the cover a bit more each day, but you don't have a progress indicator the way you do with the wilting.