heat mat temps for peppers
 

I am not sure how to word the title to get help. Here is my situation: I have been starting peppers from seed for many years and seem to have a real problem getting the seedlings to grow after germination.

All the peppers are in flats with heat mats. Peppers like warmer temperatures. It seems the problem is the soil temp is not high enough; more like 75 degrees than the desired 85-90 degrees.

Question: If the heat mats only add 10-20 degrees to the ambient temperature, how can the soil temp be raised to 90 when the warmest my basement growing area will get is 65 degrees? ( without increasing the whole house temp up to an unbearable number and expense?).

My idea is to attach a thermostat with a soil probe to the heat mat, but will the heat mat be able to keep the soil hot enough? I have several heat mats but no thermostats. On e-bay there are several in the $30 range. Will that help solve my problem?

Will something like this serve your needs?

[url]http://tomatoville.com/showthread.php?t=13185[/url]

If you start fooling around with an enclosure like this early enough, before you need to start seeds, you can probably make adjustments to the wattage and ventilation so that you don't even need thermostats, if you have it in a space that has a pretty constant temperature, like a basement.

Jim

Thanks. Worth a try.

I ran into the same situation as we keep our house on the cool side. My fix? I picked up one of those small, plastic covered, 4-shelf greenhouses when it was on sale at Menards or Tractor Supply for $19.99. Put it together and zip-tied the wire shelves to the framework for a little more stability before I put the plastic cover on. It's held up for a few years now and still looks good. For the most part, I keep the heat mat on the bottom shelf, and between that and the lights I add for the new seedlings, the whole thing stays warm.

I like your idea of keeping the soil warm. My peppers didn't want to grow last year either. I ended up buying about a dozen transplants. Eventually the plants I started caught up in size, and they produced like crazy but all were very late. Wish I had been more patient and saved $$.

Foam boards (I use the lid of a foam beach cooler) placed under a heat mat helps to direct the heat upwards to the soil, rather than heat the table or shelf beneath the mat. The gain is only2-3 degrees, not anywhere near 90 degrees, but better than wasting that heat - Lisa.

I made a box to grow peppers in the basement. Ambient temperature is about 60F. I use a 200 Watt air heater controlled by a baseboard heater thermostat. (It directly switches the AC current on and off). I set the controller to turn off the heater at 85F. I run the heater and 6500K fluorescent lighting 16 hours per day, then allow it to cool to ambient temperatures at night.

This is the same apparatus that I use to do germination testing. The box is lined with aluminum foil to make the most use of the lighting.

[IMG]http://i1074.photobucket.com/albums/w406/JosephsGarden/Technical_Data/controler-temperature.jpg[/IMG]

Hey Paul!

Sounds like you're getting some good ideas. Just wanted to add a bit on to my answer at NJT in that 1 thermostat will control multiple mats.

TimothyT

[QUOTE=PaulF;383197]I am not sure how to word the title to get help. Here is my situation: I have been starting peppers from seed for many years and seem to have a real problem getting the seedlings to grow after germination.

[/QUOTE]

If it is warm enough for them to germinate I don't see why you would have any problems with growth after that. Germination requires the most warmth in my experience. I germinate superhots (non-superhots don't require temps as high) at 90+ degrees then move them to an area that is roughly 70 degrees (still in flats) and once they are potted up they move from the basement to the greenhouse which is often in the 50's.

Are you sure they are getting sufficient light?

Good point biscgolf. Tomatoes, herbs and flowers of all kinds also are on the list of seed starts and seem to do very well. Perhaps a complete light bulb changeout is in order this year just to be sure. Or maybe two hot whites on the peppers will help.

I run my heatmat at 75 and they seem to do fine.

I take my peppers off the heat mat and pot them up into something a little deeper as soon as they have germinated. I found if I left seedlings on the heat, they suffered - maybe the soil was a bit too warm.

There's a pic of my pepper seedling setup attached. Hard to see, but there's a baseboard radiator at the level of the lower shelf, which gently heats that shelf. Peppers on the windowsill didn't get that warmth nor the shelter from the cold window, but they did well too without anything to warm the soil. They didn't grow as fast as the lower shelf, but as you can see, the lights could have been closer to them too.