Should I use the heat mat?

I bought a year's subscription to the Seed of the Month Club at this website last year, and I've been pretty impressed with what I've been getting. Lots of seeds that I would have bought anyway, that are meant to grow where I'm living. However, I just got my new seeds for this month, and I was kind of upset that I got onion SEEDS! Lol, I didn't really think you could grow onions from seeds!

But now I'm thinking, maybe I should try growing my onions from seeds! That would be kind of fun, and if it doesn't work out, I can just go out and get some sets.

I plan on starting some broccoli and cabbage inside early too, about the same time I think you should start the onions (so that works out). I have a hothouse with a heated mat and a plant light, but I don't know if I should use the heated mat for the onions, broccoli and cabbage. They kind of like colder weather, don't they? Will growing them with the heat mat on (which makes the hothouse about 70 degrees) stunt their growth? This is my first year for trying the broccoli and cabbage as well, so I don't really know.

Any advice would be appreciated!

A heat mat is mostly used to start seeds, even the cool-weather crops. They like to have a warm bottom so they can germinate. If its too cool, they'll take forever and a day to germinate. The heat mat is great. Once the seeds germinate, you can put them under the lights and hopefully the area is in the 60*F range so they will keep growing in good health. If its much cooler than that, I'd suggest a small electric heater in the room or put a tray of seedlings on a heat mat. Cool-weather crops like it a little cooler than warm-weather crops, but not COLD.

LS it is just the right time to plant onions from seeds. I have no heat mat, but I do have an old heating system with steam radiators and radiator covers. I put my little planted boxes of onion seeds on top for a few days and they sprouted no problem. The onion seedlings are now camped out on the window sill. Some folk put their seed starting trays on top of the fridge for a few days.

quiltbea wrote:A heat mat is mostly used to start seeds, even the cool-weather crops. They like to have a warm bottom so they can germinate. If its too cool, they'll take forever and a day to germinate. The heat mat is great. Once the seeds germinate, you can put them under the lights and hopefully the area is in the 60*F range so they will keep growing in good health. If its much cooler than that, I'd suggest a small electric heater in the room or put a tray of seedlings on a heat mat. Cool-weather crops like it a little cooler than warm-weather crops, but not COLD.

I have an old heating pad (remember those?). Would that work for a heat mat?

Camp, what is your last frost date? The ANSFG book says to plant onions 8-12 weeks before your LFD, and for me, 12 weeks before would be February 27th (since my LFD is May 21st). Or is it ok to plant onions earlier than that?

Quiltbea, thanks for the information! I didn't know I wasn't supposed to use the heat mat all the time, lol. The way the packaging talked about it, you'd think it was absolutely necessary to have it on at all hours. (Maybe that's why my plants were kind of on the leggy side last year.)

Luci, I've heard of people who do use an old heating pad in a pinch, but most people don't recommend it since they're not water proof and aren't meant to be left on for extended periods of time.

littlesapphire wrote:Camp, what is your last frost date? The ANSFG book says to plant onions 8-12 weeks before your LFD, and for me, 12 weeks before would be February 27th (since my LFD is May 21st). Or is it ok to plant onions earlier than that?

I would say average last frost date is May15. But I can set onions out into the garden a few weeks early. They can tolerate the cold pretty well.

littlesapphire wrote:Luci, I've heard of people who do use an old heating pad in a pinch, but most people don't recommend it since they're not water proof and aren't meant to be left on for extended periods of time.

Good points, littlesapphire...thanks!

Another issue with heating pads is that most turn themselves off after about 30 minutes.