cold frame/ warming mats?

I was wondering if anyone has any info on building a coldframe? I can't tell if it'd be cheaper to just buy one or to build one. Also, can you start tomatoes/peppers/etc in a cold frame or is it only for hardening off plants already started? How about if you use a soil warming contraption?
Which brings me to my next question: has anyone used soil-warming cables or those heat mats you can buy? Any recommendations on what to get? I am planning to grow a bunch of seedlings in the next few months - maybe a total of 200 plants (several different kinds), and I'm trying to plan what I need and how to set things up. Any suggestions would be great!
Thanks,
Mara

I should add - I don't have any equipment yet (other than the plastic flats I've been saving), and it's just for my personal plants. And I don't have much of a budget....

If you go to the library and check out either the Square Foot Gardening Book, or Bob Thomson's "Victory Gardens", both have simple instructions to make a cold frame.
Of course cold frames can get really fancy and have automatic vents, but basically it's a warm/sheltered place for veggies. My cold frame consists of an old wood-framed storm window I got at a second-hand store for $4. I was lucky to have an old book-case I was going to throw out that the window fit PERFECTLY on top of. Now I'm just waiting for DH to build another "level" to make it higher, and it will go on a gentle slope we have in our yard. Easy Peasy!

MARA

check out my topic---------my seedling house

It's not exactly what you want and I don't know if you live where you have to have something that looks 'nice' but I made a space to harden stuff and start stuff a few years ago on a really tight budget. I bought bales of straw/hay and used old glass shower doors for the top. It worked great. I filled it twice over with seedlings I had started in the house. When I was done with it, I dragged the shower doors back in and shredded the straw and tilled it into the gardens.

Thanks for the suggestions. They all sound do-able and straight forward. I'm just nervous - I haven't grown much from seed, and I bought a bunch of different varieties - I would hate to get everything growing and then kill them right before I plant them!

What about a regular heating pad set on low for germination? The kind you get for injuries, etc... do you think that would work?
-Mara

I have used a regular heating pad many times to start seeds. You just have to watch the heat. It is great for getting the seeds to sprout but once the seeds sprout and get roots going, it can cook them. Also the soil will dry out much faster with heat.

If you can find a very old heating pad it might work but the new ones all have an automatic cutoff. If you have a lightbox or can make one they are not too expensive. Another way to avoid buying a mat is to enclose a shelving unit with plastic and put a lamp with a 60 watt bulb on the bottom shelf. It produces a lot of heat in the enclosed area. You will have to keep track of it and make adjustments accordingly. Jessamine

someone out here told me that he started his seed in a wooden box ---with christmas lights as the heating cable-----imagine that. and it worked.

I forgot all about the light box idea. Was it paulgrow that posted about that not too long ago? I remember seeing the metal box with the light bulb underneath but can't remember where I read it on here. That could solve two problems, heat for above and light for below!

The Christmas lights are a good idea too. I guess where there is a will there is a way!

There are tons of threads on cold frames if you just go to "search". http://davesgarden.com/forums/search.php?forum=&search_text=cold+frames&limit=0&limit_poster=&Search=Search

I have never used one, but I think it would be a fun project to build a simple one. You can find used doors and windows at most any salvadge yard.

I opted to go with the box heated with the lightbulb as a heating device, and then I'll worry about the coldframe when it gets to be spring-like. I found a small wood box, bought a sheet of metal to fit over it, and a small lamp fixture to go underneath. I'll put the flats on that for germination. In the meantime, I've been using a regular heating pad and it seems to be doing fine. Thanks for the help!
Mara

Try this.

http://davesgarden.com/forums/t/182057/

I have 3 of Paul's heat boxes now.

Mara, just for the initial germination, if you're not doing many seeds you can't go very wrong with the top of the refrigerator! Most seeds like to be kept fairly moist, so putting the little plastic flats in a plastic bag works fine--just take them out a couple of times a day and turn the bag over, to minimize the condensation. Then when the shoots start showing, move the plants to the light. Use something like No-Damp when preparing the soil for the seeds. (To keep them from getting mouldy--it's an anti-fungal.)

Cold frames--I love the hay bales & shower doors idea--are great for crops that like a cooler germination. Lettuce, for instance, prefers to germinate around 45 degrees.

In your zone, if you start seeds inside and get them to transplant stage before putting them in the garden, you'll probably find that floating row covers give you enough protection. Just be sure to harden them gradually first. (Outside for just a few hours each day, while still in their little pots.)