Heat mats as source of heat in greenhouse?

I moved my very young starters of pepper, tomatoes and eggplants into greenhouse I set up on the deck. There is a heater there keeping 67F day and night. I hopped it will be sunny, so days will be much hotter, but 2 very dark and cold days so far. I wondering if it makes it better if in addition to heater I will use heat mats under pots to keep soil warmer than the air? Will it help or hurt even more? What usually happens when sun comes out, the air heats quickly in the morning and soil stays much colder longer, so plants wilt. I hope that warmer soil will make them functioning better.

I find that for my greenhouse it’s better to start seeds indoors on a heat mat, then move them outside as soon as most are up. I don’t keep my greenhouse nearly as warm as you do though, I try to not dip below 45F at night.

There is nothing like a greenhouse once they get going. They grow so amazingly well. I’m picking tomatoes in my greenhouse right now. From seeds I started two months ago.


I would usually keep it colder at night, but they are just 1-2 pairs of leaves stage and had been growing at home at 75-85 thanks to the lamps and 2 refregirators in the growing room 2 days ago