Lower temperatures for seedlings once germinated

[ottawagardener]

Someone asked me via my blog if there was any advantage in lowering the termpature of a heating mat for seedlings (specifically peppers if I remember correctly) once they have germinated? I don't generally use a heating mat but presprout and then grow on so I can't really say. Not only that but I haven't heard of this. I suppose you wouldn't want to get lots of floppy growth but anyone know something specific?

[garnetmoth]

I put peppers and tomatoes in the bathroom with the chicken brooder this year (warmest room, have changed some vents and if you keep the door shut its 10F warmer than the rest of the house) and they popped up quickly and got a little spindly. I think its OK because they are all rotated between windows and lights now in a cooler room, but id quit warming them as soon as they sprout unless you have great strong lights so they dont get spindly.

[grunt]

Only possible advantage that I can think of in lowering temperatures might be a slight amount of hardening, and maybe a small increase in root production versus top structure (and that's a guess). Either way you would want lots of light to prevent legginess.

[bertiefox]

I find it a real problem trying to maintain a 'sensible' temperature for seeds and seedlings at this time of year. We are getting blazing hot days with sunshine pushing temperatures in the polytunnel up to 100F, and then night time frosts down to 0C (32F) at night. My peppers, tomatoes etc are ok, but I've lost all the brassica seeds I sowed in modules as they have probably 'cooked' or gone dormant. I've shaded them in the tunnel, but they still get too hot.
What kind of shelter do other people use in sunny spots when temperatures can alternate like this, to maintain a steady temperature of 70F or so, with enough light?

[Joseph Lofthouse]

Mar 25, 2011 13:24:47 GMT -5 bertiefox said:

What kind of shelter do other people use in sunny spots when temperatures can alternate like this, to maintain a steady temperature of 70F or so, with enough light?

I put brassicas into their permanent place in the ground as soon as the snow melts and/or as soon as the soil can be worked.

[ottawagardener]

I often put brassicas out very early, when there is still snow possible but I cover them with a pop bottle cloche (open at the top) and remove during the day when it's warm. I also recover them, with a brick on top, early in the evening while the air is still warm to maintain the temperature. I haven't had buttoning yet. This year, I might use row covers if warranted. Supposedly, you can get premature head formation with prolonged temperatures under 7C (if I remember correctly). I haven't actually measured the temps so I'm not sure if I'm achieving this but I also haven't seen this effect yet.

[wildseed57]

Brassicas are a hard one for me, but I try to get mine planted in March as soon as I can or in Late September and then cover when there is danger of frost in late October. I had thought that I would be able to put in a couple poly tunnels last fall, but it looks like maybe it will be this fall before I can get them. As for turning down the temperature on the heat mats, I normally take away the heat mats once the seeds have sprouted as I usually put them under my lights to keep them from getting to weak and fall over . Normally I'm set up pretty good except this time I sprouted more peppers, tomatoes and eggplants and am hard pressed for space. I need to set up a couple of my 8ft. lights, instead of my four foot system, as I'm quickly running out of room. I did mass plant some of my yellow Bi-colored tomatoes into a single container which saved me some space along with some cherry tomatoes in another one. By doing that saved myself about three feet of space although only temperary. All of the plants are kept about near 70F so that their growth is not slowed. right now I'm looking at nearly a hundred seedlings with about a hundred more still to come up.
George W.