When to use bottom heat for seedlings?

The bag of Jiffy seed starting mix I purchased says to remove seedlings from the heat mat at the first signs of germination to prevent stretching. (What is stretching?) Another source--supposedly an expert--told me that as long as my room temp is about 70 I don't need extra heat to germinate, but to use heat after they germinate and the plants would grow faster. Can someone tell me which is the best procedure? I've read that peppers prefer about 80 degrees to germinate, which would require putting extra heat to the trays.

Stretching is another way of saying they'll get leggy. If you keep the heat mat under them that can contribute to legginess, and not having your lights close enough to the seedlings can make them leggy as well. As far as whether your room temp is enough, it all depends on what type of seeds you're starting. With the peppers if they need 80 degrees, then you'll need a heat mat, but there are plenty of other seeds that would germinate without the heat mat. The seed packets will often give you instructions about germination temperature.

You'll get some germination on pepper seeds at regular room temperature (especially if it's above 70'F), but it'll be much faster with heat. Pre-soaking pepper seeds in weak chamomile tea or water with a splash of hydrogen peroxide (1 Tbsp. of 3% per quart) will also speed germination.

For more information on lights and heat mats, check out my two "Seed Starting 101" articles... click on "critterologist' to the left of this post to get to my home page, then scroll down to see a linked list of article titles. (Or go to today's article on peppers... at the bottom of the page, you'll find a link "for more articles by Jill.")

For more information on starting peppers from seed, see my post here http://davesgarden.com/community/forums/p.php?pid=2520811.

I'm not trying to argue with your expert, but a lot of seeds seem to germinate better/faster with extra heat... but the instructions then say to grow the seedlings on at cooler temperatures... and that seems to work out well. From experience, I can tell you that if you leave tomato seedlings on a heat mat for even a day or two after germination, you can end up with the tallest, spindliest little "stretched" seedlings you ever saw!

I just germinated a bunch of ornamental peppers (about 6000) with the soil temps at 60-65 or so and I got great germination. They came up in about 5 days. One of the keys to keeping the soil temps up is to use hot/warm water when misting during germination- when you use cold water, it takes about 6 hrs or so for the soil to come back up to room temps.

Tigerlily, how long did it take your pepper seeds to germinate? I've certainly had good germination on them before getting a heat mat (didn't mist with hot water either), but the heat mat just makes them pop!

they came up in about 5 days-give or take a day. Thats about average for them.

Wow! I didn't expect so much wonderful advice so quickly. Thanks to all of you. I will read the articles this morning. I'm expecting tabasco seeds to arrive today, so the timing is great. I didn't soak my bell pepper seeds I planted last night, so I'll be sure to use warm water when needed. I ordered a 20 x 20 heating pad that should help with two trays. The bell peppers I planted 10 days ago still haven't germinated, but I won't give up on them yet. The pkg. says 10-21 days.

This web site has been SO helpful!

Tigerlily, that's great! Those are the kind of results I get with my heat mat... but it sure took a lot longer for me without the heat. Maybe your misting is the key.

As I've said before, there are lots of different ways to do almost anything... and if you find something that works, there's no reason to change it!

Sharkey, if you can, try sticking those bell peppers in a warmer spot, even if it's not under the lights. They won't need light until they germinate, and a little extra heat might goose them into action.

I am really busy with the crop right now, but I will try to take pictures of them, it might be interesting for some. Also, how I have the plastic set up etc.
I am not looking forward to transplanting them! I still have to fill the pots for them, but I have another week to get that done, and the transplanting should take only 2 days ( I hope). Once everything is set up, pots watered down and room made, you can usually get the pace up. One person pulls and one plants. Right now I am working on transplanting begonias. Then the vinca are ready (2nd round-late order) and then the peppers. Rudbeckias in there somewhere too-as well as other stuff....lol I don't know why I am telling you all this-just came in for a break and my mind won't leave the grhouse-I guess I should have dragged it out of the grhouse with my body! Sorry for running on!
Did I forget potting up the cannas and grasses (thats tonight) and de-eyeing the caladiums (tonight) and planting them tomorrow. Cutting back petunias (going on right now by others) lol this is how I am at this time of year. It takes me about a week to come down after the crop.