Heat mats-whats the best model?

Looking to purchase some electricheat mats for upcoming spring transplants. What is the current best brand/model for bonsai growers? Any suggestions appreciated.

I use Hydrofarm Comercial mats,

They are thick sturdy powerhouses that should last me a decade or more. They do have a proprietary daisy chaining connection, so the first in the row (model #MTMDU) is different from the next 4 in the chain (# MTMDA).

You can have 5 of these daisy chained and that is 25ft of heat beds!

They also have hobby grade which are great as well and i have used them for many years on other projects.

This is the thermostat that I have controlling things:

Inkbird ITC-306T

I have the 60x21” versions and it can class if your benches have poles or things that are in the way, these do not bend around things. but as long as your benches have 21” of clearance between poles from the back, the pads have no problem spanning 2 racks. I had to do this with 48” racks i had. Hydrofarm does mats meant to fit smaller racks in their non commercial grade.

hope that all helps


In a stream a while back, Ryan mentioned that they had issues with the wires they had used in the video in the Archive (where Troy makes a heat bed), and went back to mats. At the time, this was the mat they were using:

You also need to get a temperature controller separately.


I have an iPower (Amazon link below) at the bottom of this recovery bed, it’s reliable so far


First time responding to a post so sorry if I mess it up. I’ve been using the Redi heat brand with the matching thermostat. It has a probe that you place in side the soil mass about 1”up from the bottom of the box
You have to keep an eye on the temp of the actual root mass at the bottom, for that I recommend a small thermometer to check periodically. Once soil is dry it will not transfer the heat so there you have to keep it hydrated. Redi heat sales folks are helpful as well. - good luck !


I have been using the OBC ones with temp controller for 3 years now with zero problems.

What are these please?

The link in my post above was to the OBC mat.

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Thank you fellow bonsai friend.

So thanks for the heat mat recommendation, been searching for a viable option for weeks. Can anyone enlighten me on the use of the commercial OBC mats? The guidelines say they cannot be covered with soil? How is the heat distributed evenly, most systems use some vamp substrate over mats for this? Seems like even a light breeze would negate any benefits? Thanks in advance to the collective mind.

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Next question- going to go deep here on heat beds- if there’s a plumber in the house please comment on viability of this idea. So I’m a grower, producing material specifically for bonsai, expanding my operation. Research into heat beds shows that many are notoriously unreliable and costly to replace consistently. My thought is to adapt a system with recirculating warm water to hear the bed, similar to a radiant home system. Utilize a recirculating pump, tubing, either copper or pen, and an on demand propane water heater. System is expandable as more beds are needed, and components are reliable and long lasting, system can easily be embedded in the warming bed, and water will not cause ant damage to system. Pricing components comes out to $300-350.
Any thoughts on viability would be welcome- I’m just searching for a flexible system that can grow with my operations and be low maintenance.


REMINDER…to replace the normal wall plugin with a GCFI outdoor plug! Outdoor plugs should already have one…
Cheep safety upgrade. If the system gets wet AND shorts, you will pop the GCFI rather than shock whatever (whoever…) the wet mat touches. The shorted amperage draw may not be enough to pop a older house system breaker.
Call an electrician if you dont know this move.
Shut off the applicable system breaker before YOU do this.
You can thank me later…

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Great information being dropped here.

  • 1 for KurtP (even if it trips the breaker, if the fault happens while you handle it …. )
    I used a heat cable and this developed an issue (was not the highest quality though) where the complete insulation broke open and also part of the wires became exposed.
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Great invention… plug-in Ground Fault Circuit Interupters (AND GFCI curcuit breakers…), they DO pop at the first SURGE of amperage; ALWAYS saving you from shock. Ground Fault Circuit Interupter.
BTW, GFCI plug-ins are ‘Electrical Code required’ for outside plug-ins! Even if they have GFCI main breakers.
(A little light reading, anyone? Before a kitchen remodel…)
Real local story… A local dog walker out on a winter day. Older corroded electrically heated WET concrete sidewalk…
Dog yelped, jumped, collapsed, died. Person kneeled to help, and got the s**t shocked out of them. Survived.
Police called. Power shut off. Finger pointing. Hand wringing. Lawsuit.
Didnt trip the breaker… not a amperage SURGE.
Very enlightening story…
Oh, ya. If you run a cord from a INSIDE (guarage, basement) plug-in out to any WET environment , now it is considered an OUTSIDE plug-in…, needs a GFCI.
I’m not an electrician… When in doubt, consult a licensed Electrician.
Be safe. Be proactive… Spread the love! Save a life…
… Bonsai On!..

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In the heat bed construction video in the library, Ryan discusses this. The ‘sandwich’ for the heat mat is stable base, rigid foam, heat mat, plastic, soil/gravel, pumice. The plastic separates the heat mat from the wet components. If your source of heat is not effected by water, then you can run it above the plastic - so you’d be stable base, rigid foam, plastic, and then soil/gravel with heat source. In a subsequent Q&A, Ryan mentioned that they went back to the heat mats because the in-ground contact wires they used for the video ended up shorting out.

For mine, I built a frame using PT 2x6 lumber, and half inch PT plywood for the ‘stable base’, then rigid foam, then another layer of PT ply to protect the foam from being beat up, then the OBC mat, then heavy duty plastic. Then I put it into my greenhouse - it was very heavy at this point. Then I added gravel to hold down the plastic, and finished with pumice.

I did the heat pads in a slightly simpler mode as @jas2008 listed. Nice thing is that unit can be moved fairly easily.

For a more permanent solution the use of heated water in tubes as @SCBonsaiGrower describes makes lots of sense. I would probably use plastic tube or pipe rather than copper due to the cost even though the heat transfer through the plastic is much, much lower. This should not make too much difference since the goal is to maintain the bed temperature into a damp media rather than changing the temperature. Another advantage is that you might be able to incorporate solar panels to supply some of the heat, but if your climate freezes that loop would have to include antifreeze which negates the leak safety issue in the bed.

Thanks Jas2008, I have ordered the OBC mats, are the the type that has to be protected from water? Can’t seem to find much detail on them? Hopefully they are reliable, I’ve heard nothing but bad reviews on the cable systems. I’m trying to develop a growing facility so reliability and expandable is important.

As I understood the Ryan’s presentation in the video, you do need to put the mats under the plastic.

I believe you are correct and I put mine under construction plastic