heating mat

tdnmm Tue Feb 17, 2015 8:32 pm

Hello everyone,
What can I use under my heating mat to raise the temperature to 85. I have a thermostat but it only gets up to 80. I went to home depot and purchased a thermal insulation board. After reading the label, it said it was combustible so I removed it. Thank you-Tom

quiltbea Tue Feb 17, 2015 9:12 pm

$glad you\'re here$ to the forum.
Why the heck would you want to increase the heat to 85 degrees? Starting seeds don't need that much heat and once they germinate, they can get by with even lower temps, like in the low- to mid-60s, to give them a spring boost.

boffer Tue Feb 17, 2015 9:35 pm

Welcome to the forum.

I put my heat mats on 1 inch foil faced foam board. (foil up) I let the built-in thermostats do the work. I cover the trays with clear plastic covers to keep the heat in. No problems in 8 years.

I'm as puzzled as QB about the need for higher temps. There are several charts in the back of the ANSFG book. The temp points listed in your range are 77° and 86°. Only a few variety of seeds germinate faster at 86 than 77, and then only by a day or two. Interestingly, the percentage of seeds that germinate at 77 is better than 86 for nearly all varieties listed.

Is there something out of the ordinary that you're trying to do?

**Turan** Tue Feb 17, 2015 11:39 pm

The only seeds I find I need extra heat for are peppers. I used a heat lamp over them as well as the heat mat underneath. Gotta be very careful then to not dry them out.

**sanderson** Wed Feb 18, 2015 12:11 am

Tdnmm, Welcome to the Forum from California! $glad you\'re here$

Are you trying to germinate exotic/tropical seeds? Did someone tell you that you needed 85*F? My thermostat is set 68-72*F and the small warmth of fluorescent tubes is sufficient to germinate veggie, herb and flower seeds. I have the plastic trays on tile flooring so I put a doubled towel under the trays and have the trays doubled up with cardboard between the 2 pans as insulation from the cold floors.

**camprn** Wed Feb 18, 2015 1:46 pm

Ditto what sanderson said. And you only need that temp for about 24- 48 hours. Also consider you will still get germination at lower temps but it may take a day or two more.
heating mat Temperature-chart

**AtlantaMarie** Wed Feb 18, 2015 3:22 pm

Hi Tom. Don't have any heating mats, so can't chime in on that.

But welcome from Atlanta, GA!

quiltbea Wed Feb 18, 2015 4:18 pm

Camprn........Great chart and from the look of it, the range from 68-77* seems ideal for just about everything.

yolos Wed Feb 18, 2015 5:33 pm

Camprn - just to make sure I have it right, are the temps in that chart soil temps or air temps.

**camprn** Wed Feb 18, 2015 6:26 pm

yolos wrote:Camprn - just to make sure I have it right, are the temps in that chart soil temps or air temps.

soil temps

countrynaturals Tue Mar 26, 2019 2:24 pm

Are heating mats just for sprouting? Once they break ground can I take them off the heat and start something else? I only have two heating pads and way more seeds to sprout.

OhioGardener Tue Mar 26, 2019 2:40 pm

countrynaturals wrote:Are heating mats just for sprouting? Once they break ground can I take them off the heat and start something else?

Yes, yes. As soon as the seedlings sprout, I removed the plastic dome and unplug the heating mat. The seeds need (want?) heat to germinate, but the plants don't need heat to grow.

countrynaturals Tue Mar 26, 2019 3:34 pm

OhioGardener wrote:
countrynaturals wrote:Are heating mats just for sprouting? Once they break ground can I take them off the heat and start something else?

Yes, yes. As soon as the seedlings sprout, I removed the plastic dome and unplug the heating mat. The seeds need (want?) heat to germinate, but the plants don't need heat to grow.

Thanks, OG. You always give me the answers I'm looking for. I love you

**sanderson** Tue Mar 26, 2019 4:20 pm

**jimmy cee** Tue Mar 26, 2019 10:20 pm

A much better solution for heat ( if needed ) would be a slow cooker...( crock pot ) placed at the bottom of your seed rack. open with no cover, set on low. water will need to be added everyday, and moisture will also be added as the water evaporates from the pot. I covered my rack with plastic. Kept the temps below 75 degrees F. Spinach seeds are noted not to germinate above 75 F. Even without heat, an enclosed cubicle will maintain proper temps by just lighting, even using the low temp bulbs.

yolos Tue Mar 26, 2019 11:51 pm

I tried Jimmy's method of putting a slow cooker placed at the bottom of my seed rack and inside a small greenhouse shelf and it worked perfectly.

**sanderson** Wed Mar 27, 2019 3:50 am

Good to know.

I used the new heating mats with no improvement. Back to the drawing board for 2020 germination.

**trolleydriver** Wed Mar 27, 2019 9:24 am

sanderson wrote:Good to know.

I used the new heating mats with no improvement. Back to the drawing board for 2020 germination.

Do you have a thermostat on your heating mats? If not maybe they got too hot.

yolos Wed Mar 27, 2019 10:07 am

I have been starting seedlings for years and using a heat mat. I used an oven temperature gauge to test the heat of the soil. What I found was that the soil got too hot with the heat mat on full time. So what I used to do was unplug the heat mat throughout the day. But this year I finally purchased a heat mat with a thermostat that will turn off the heat mat when it reaches a preset temperature. Works like a charm.

**sanderson** Thu Mar 28, 2019 5:18 am

Yes, the heating mats had thermostats and probes. The temp was around 70*F. I had a large number of herb failures, also. I will have to buy some starts this spring. Sad

ralitaco Thu Mar 28, 2019 11:05 pm

jimmy cee wrote:A much better solution for heat ( if needed ) would be a slow cooker...( crock pot ) placed at the bottom of your seed rack. open with no cover, set on low. water will need to be added everyday, and moisture will also be added as the water evaporates from the pot.

Wow!!! That is genius.

**sanderson** Sun Mar 31, 2019 11:14 pm

Now, Jimmy Cee is going to have a big head. Very Happy

**jimmy cee** Mon Apr 01, 2019 10:45 pm

sanderson wrote:Now, Jimmy Cee is going to have a big head.

goes with the rest of my body, however , head is getting bigger than my frail body every year....ha ha...

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