Linnea--I live in Il zone 5/6 and also have a coldhouse. I use a heating pad (low heat) to warm the soil under my seeds. I'm sure it would work for your bulbs. A few years ago I planted a flat of lilys to give them a head start without heat and they did fine. from--- Lawrenceville Illinois Paula

I don't know how cold your house is, but bulbs like caladiums require more heat than you would get from a heat mat at 70 degrees if your house is 65 or less. You might do it by covering the plants, heat mat and all, with a clear plastic tub to keep the heat confined. Of course this is only my opinion based on my Caladium growing experience. I have other bulbs such as Gloriosa lilies doing fine on a heat mat with air temperatures going down to 50 degrees at night. Al

So heating mats only get to about 70 degrees? I was wondering, I couldn't find any specification on the ads. I tried starting them inside last year, and nothing happened until I was able to put them outdoors.

That's a good idea with the tub. I bought flats with thin plastic clear covers to use, but a Rubbermaid (or similar) tub would hold in more heat. I could even wrap up the whole assembly in a blanket!

It's about 62 at night, 66 to 68 daytime.

You might try starting a thread on another forum, just asking about seed mats and their temperatures, and what kind folks have.

You might try asking at Tomatoes as I see in their FAQ that temps of 70-80 are optimum, and I'm sure that some folks who have basement set ups, or something similar, aren't keeping the room at 70-80, thus are using mats.

I know the newer heating pads shut off after a certain amount of time, and I don't feel they would be as safe as an actual seed starting mat.

My house is cooler too, without any place you could really call 'warm' for starting seeds. In the past, I started some seeds in my gas oven (no pilot light) with the light left on in the oven. The temp stayed at 70+ degrees with the light on. I put a big note on the oven ...DO NOT USE-SEEDS! as a reminder to not accidentally turn the oven on with the seeds in it.

Thanks, Sue!

About 3 years aso I tried an old electric blanket. To me, it didn't feel very warm: but then out of 30 caladiums, only 1 sprouted. I didn't know whether they failed due to my ignorance or being cooked.

I bought a set of Christmas lights in the tube for about $5 at walmart and then coiled them to form an oval. Then I placed my tomato flats on top and it heated the soil to 80 degrees! IMO worked better than an expensive heat mat! I may try my caladiums on it. Is it true they don't like to be transplanted? Should I plant them in newspaper pots?

Jodie