This year I moved my seed-starting to an unheated (and poorly insulated) basement, so I'm leaving the heating pad on the peppers for now. I remove the domes after germination, and I remove the heating pad from most things. I use some seed-starting kits that I purchased a zillion years ago, and I certainly didn't pay much for them. Maybe $3 each? The domes are getting a little cracked, and a little yellowed, but I'm still limping along with them. I've lost some of the seed-starting cells to cracks and crushing, but other cell-packs wander in from the nursery each year, so I get by. Several years ago, I was able to replace just the domes for $1 each, but I've been having trouble finding the pieces separately in recent years.

Absolutely you can grow these seeds without a mat (tomato, squash, peppers) and many others. They may take a little longer to germinate but they definitely do not need a heat mat. Most seeds that do require heat to germinate will say so on the seed packet. And while a lot of seeds will germinate earlier with bottom heat, there are plenty that are hindered by bottom heat as well. I've been starting a lot of seeds in the house early for many years and have only started using a heat mat the last couple. The only reason I started using it was because I got one for a gift. I will admit though, it is nice to get faster germination on some things. But definitely not a neccesity for most seeds.

sal-wa, i usually start tomatoes indoors end of February but i have greenhouse (unheated) and keep them in gallon pots there until weather permits to plant outside. They are usually starting to flower by this time.

The other advantage to wintersowing, besides being less expensive than buying (what pathetic selection they have available) at the nursery, and also having the space to coddle seedlings all over inside--messing with supplemental lighting, etc., and that your plants will be hardier and already hardened off, is this: your plants will also be hardier through the hotter months, and more resistant to the cold at the end of season. My wintersown tomatillo survived a pretty hearty frost last year, but the indoor-start one (yes, same seed/variety) didn't make it. However, one of the drawbacks is that, for some plants, there won't be enough head start to get big enough to get some harvest. For example, if you have longer-to-ripen tomatoes, they might not be ready to go before the first frost. Also, peppers will have a later start, etc., and something that didn't occur to me until a few days ago, is that my "120-day" okra (it's not really that long to harvest since it's a continual thing) will be so far behind the 8-ball that it might be August before we get our first okra, whereas if I have indoor or nursery starts, they are usually flowering in June. This might be particularly true if your actual growing season is shorter, like Bonnie's. The other thing to remember is that not all things are suitable for true wintersowing--basil and some herbs are a little too intolerant of the cold that if they sprouted then there was a freeze, they might not make it. However, if you're starting now, I think you're good to go on just about anything from the cold-intolerant timetable. That being said, I always start some stuff inside, and try to put it outside for as much natural sun during the day as possible, then bring it in at night until the nights are warmer. I do "backup" starts for the tomatoes that I can't live without (so then, will someone please explain to me how I have over 40 starts? Oh yeah... the SWAP!), and ALL my peppers and herbs--and certainly, the cherished okra. Also, I stupidly started some cipollini onions WAY too late (but I bought the seeds, and they'll be no good next year) inside, so we'll see if those guys turn out. Of course, Trudi D will tell you that she started wintersowing as a great experiment because she was going cabin-crazy in the deep of winter and just wanted to make some mud pies in January... (My husband now wonders, since we move our tomato containers into the garage and harvest until February, if he will ever see his wife's fingernails without any dirt under them... I'm goin' with NO)