I use this Vivosun brand. It has a number of sizes to choose from, and it has lasted the longest. Haven't used one with a thermostat.

https://www.amazon.com/VIVOSUN-Waterproof-Seedling-Hydroponic-Standard/dp/B00P7U259C/ref=sr_1_3?ie=UTF8&qid=1522153940&sr=8-3&keywords=grow+heat+mat

Thank you.

how long do you leave it on at a time and on what setting?

I picked based on dimensions. I'm sure there are quality differences but I don't think it will be an issue for me (based on geographic location and climate). Someone further north may have a stronger opinion on brands.

I've used the one linked with rose seedlings. I leave it on until the seedlings get big enough to transplant. This year I moved my seedlings in the basement, so I'll leave it on longer if necessary. It doesn't get very warm, but if you have small seedlings with a dome and a gro light, it works. For cuttings I'm not sure if you would need something stronger.

Never bought one with a thermostat. I leave them on 24/7 and until the cuttings have 3-4 decent sized leaves, somewhere between 6 weeks and 6 months generally.

Happy Easter!

Thanks everyone

Heat mats seem to be pretty similar across multiple brands that I’ve used. Even the reptile heat mats at pet stores are made in the same vein and work well if you want a small one. I never fuss with a thermostat, but in my experience, it makes a huge difference what the heat mat is on.

I have found that concrete floor (like garage or basement) will sap the heat via conduction, so I put mine on a buffer like a piece of plywood or thin polypropylene sheet to reflect the heat up. Same happened when I put mine on a wire rack shelf in a small greenhouse, so I buffered that time too, and it was fine. But the wire rack experience showed me how much heat escapes through convection.

For efficacy, place tip of meat thermometer in soil at or below root zone before heat. Then, apply heat and check temperature every 6 hrs or whatever interval makes sense to you.

Good luck!

-s

Howdy! Here is the best horticultural heating mat. Period. You get what you pay for.

https://shop.durablegrowingequipment.com/Heavy-Duty-Seed-Propagation-Mats-and-STEM-Kits_c7.htm

Steve H

loneroc1 SW WI USDA Zone 3/4