Heating Mat Recommendations or Warnings

Does anyone have a specific heating mat they would recommend… or ones they would stay away from?


-Steve eating cheese on New Year’s Eve

Depending on your application, you may be best off buying regular heat mats intended for that purpose. However, I’ve had very good success with simply heating pads. They are very inexpensive. They work very well in conjunction with my Rootmaker 18 Express trays that I use for propagating trees from nuts and seed. The Express trays hold the cells above any surface so roots can be air pruned. With this small air gap, the regular heating pads are just right. I used them for starting Pawpaw trees last winter based on a recommendation from KSU for medium temps of about 90 degrees. The results were impressive.

Depending on your application, this may not be right for you, but they were very inexpensive and worked very well for me. I just needed to make sure I bought a version that did not have a turn-off timer or one where you could defeat the turn-off timer.

Thanks for that. My plan is to use them for both plant cuttings and seed germination.

I have a couple of 20x20 mats that I use primarily for seed germination. I forget the brand, but their wattage is sized to keep a tray in the high 70’sF from room temps (high 60’s say). If you are doing that, without much variation you probably could get away without a thermostat.

I typically use them with a thermostat (or sometimes two, one for each) since my seedling area tends to have wide temp swings and can be in full sun for part of the day. So a thermostat is needed to keep things from getting too hot on some occasions.

Although a bit more costly initially, a thermostat (with sensing bulb that you can put in the trays) is a bunch safer than a timer or just trying to remember to turn things on at night or cloudy days. But it depends on how important the starts are to you…

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Sore back heating pads?

Yep, the cheapest I could find. Keep in mind that these may get too hot for use as typical heat mats where the container is placed directly on them. However, with my Rootmaker Express Tray 18s, the tray holds the cells elevated so the containers don’t sit directly on a surface. This is so there is good air flow below the container and the roots that are directed to the holes in the bottom of the cell desiccate when they contact the air. This prunes them without causing a cut where disease can enter causing upstream branching. So, in order to get the temperature of the medium where I want it, I needed something a bit hotter. They worked very well for this purpose.

I had to return the first one because it had an automatic shut-off feature that could not be defeated for safety. There are more expensive ones that have a shut-off feature that can be defeated, but the cheapest ones have no shut-off feature for safety. These are getting harder to find.

I have also used these for germinating seed in mesh flats. I did not place the flats directly on the pads because they get too hot even on the low setting. Instead, I put small wooden blocks under the ends of the flats to elevate them about 1/4 inch above the pads.

As I said in my original post, these are probably not the best solution for most applications, but they worked well for my purpose.

I’m going to ask a stupid question, Are they waterproof?

They come with cloth covers but they are removable for washing. I completely remove them and don’t use the covers. The heating elements are sealed inside a somewhat flexible plastic pad. Since the cells have large holes and the medium I use is a very well drained promix, the pads get drenched each time I water. The pads sit on a wire rack and any excess water runs off the pad.

I’ve been using a half dozen of them for about 3 years now and none have failed yet.

Great idea! so much less expensive than the gardening types too. Thanks.

Cost is what started me on the idea. I’d recommend using a soil thermometer to get a feel for how your individual pads perform given your containers and offset distance. They are probably not as efficient as the expensive type since lots of heat is lost through the air space. In my case, it is not really lost. I built small indoor enclosures that I use to control heat and humidity for my trees. They have an electric heater in them to maintain air temperature where I want it. So, any heat from the pads that is dissipated through the air just means the electric heater runs less so it is a wash for me.


Could you name the brand you’ve been using so I could take a look…


I tried several but I think this is the one I have the most of: Heating Pad Link


I am trying to root some figs with a heat mat desinged to be placed under a terrarium for keeping reptiles. They are designed for continuous use and heat to around 100F.