Using heat mats permanently

[Tom499]

(I apologise for this post, I struggled to find anything in the search function for "heat mat", though ofc they are small, common words, which made it difficult.)

I've been using a small exo terra heat mat for my seedlings, which are still in their "dome" after deflasking.

There was space on the heat mat for a few plants, and I decided to put my Paph. michael koopowitz hybrid on there, as it has been sulking for nearly a year.

Well, I couldn't but notice that about a week later it has started to make a new leaf! It is spring, so it could well just be wake up time, but it got me thinking on heat mats as a possible long term use.

I've read snippets here and there arguing that under pot heat can increase root growth for struggling plants. I'm wondering if it could be a relatively efficient way to increase temperatures during the day (turn off the heat mat's at night), and so improve my conditions for plants.

I use S/H as my growing media (and keep my plants on windows), and do notice higher levels of condensation in the pots of the heat mat.

I'm just wondering what the long term effects could be, and if it could work as a replacement to a regular heating device.

 

[NYEric]

Sounds like a good research project, thanks.

 

[eggshells]

Hi Tom, I am growing various kind of paph species from flask. They have been growing warm this spring/summer max of 31c and minimum of 18c. I learned from one grower here that they are not afraid of heat provided they have high humidity and proper ventilation. This doesnt answer your question about heat mats but they do grow faster in warm weather. Now flowering them might be a different story but that is another chapter. We need to grow them first.

Here are my flasklings

delenatii

hainanense

barbigerum

tranlienianum

 

[Ray]

Tom,

Heat mats accelerate evaporation from the medium, so you need to increase the watering frequency - not just for the plant, but to prevent drying of the medium, which leads to more-rapid residue buildup.

I have a section of one of my greenhouse benches covered with a large heat mat. Intended originally for new transplants, some plants have been on it for over a year due to space constraints. I see no issues with the plants.

I think that mats might supplement heating, but will not become a sole source of heat, as they do little to nothing to warm the parts of the plants that are not physically within the pot.

 

[NYEric]

I will try a controlled experiment with a compot I just got.

 

[Tom499]

Thank you all for your replies.

My thoughts were on using it for post compot plants and beyond. As Ray says the mats wouldn't do much to heat the leaves etc, but maybe it would be enough to compensate for atmospheric temperatures slightly lower than desired.

Of course, as I write this, heating even a small number of adult plants with heat matts below them... that is a large surface area.

I may need to rethink this idea.

 

[littlefrog]

I have been having great luck with heat mats under my recently deflasked compots. Looks far better than I ever managed without them. Frankly I'm pretty stunned, I don't know why I didn't think of it before, I almost feel like a professional. Also using them to root up foliage plants, but you don't care about that...

Yes, it probably gets expensive to do them for adult plants. You can get the heat mat material by the foot (well, I can, at least). I'd have to look at my supplier, but last time I ordered I didn't think it was too unreasonable. I didn't get one with a thermostat or built in variable control. I plug my mats into a controller that outputs variable wattage, and just started dialing back until I got to a temperature that seemed right.

 

[gonewild]

Bottom heat is great for most plants. In the past we used hot water circulated under aluminum sheets on benches and the plants grew very well (all types of plants not only orchids).

If you think about it most orchids in nature would be attached to something that held heat from the sun. Whatever it is, a rock or a tree. it would be warmer than the night air temperature. So with that reasoning your idea of heat mats is good.

 

[Ozpaph]

I use a heat mat or 'hot bath' (aquarium heated water bath) under all my seedlings, esp deflasks and compots - in a hydroponic tent. They grow much faster. In fact when I put some of the 6-8" leaf span plants in the same environment they grow faster than when in the orchid house. Now they do get artificial light supplementation for up to 14hrs per day and its much more humid.
They clearly grow faster but on a larger scale it would be expensive to set up and heat. My aim is to shorten the early, more vulnerable, seedling phase and bulk them up fast, perhaps bringing them to flowering size a year earlier.

 

[Stone]

I've been using bottom heat for years as well. It's great for all plants out of flask. No need to worry about cooling off at night, just keep them at the same temp 24/7 year round. As Ray mentioned they do tend to dry out quickly so you need to watch them. I find it helps to have a layer of fine sand over the pad and keep this rather moist. It definately helps with humidity and seems to distribute the heat more evenly.