Recommending heating pad

[nuriko1set]

Hello!
Can anyone recommend a good plant heating pad? I would prefer a water proof one, since all my plants are on top of a shelf and when I water I allow the water to run down to the container below. Please picture:

I have mainly Phalaenopsis and Cattleya orchids, with 1 Dendrobium nobile.

I saw this one on amazon:
https://www.amazon.com/dp/B06Y19H2LC...ustomerReviews

Does anyone know anything about it? or maybe can recommend other ones? I base my purchases on Amazon reviews, however I feel more and more that a lot of reviews are fake. So I feel they are less reliant. If anyone has other vendors that they can recommend that would be great too, thanks so much!

Happy Holidays!

[Ray]

One like THIS is what you're looking fpr

[WaterWitchin]

I have a couple of the ones Ray posted, and they work well. I do like the one you posted also... I like the idea of all the different sizes they come in. May need to check into that once mine eventually croak.

[estación seca]

You can put heavy landscape plastic sheeting over the mat to keep it dry. Leave the overhanging sides long. Put the heat mat on top of a slab of polystyrene foam building insulation. You can easily cut this to size with a knife.

I have also extended the heating surface by placing the a large metal automotive oil drip pan over the mat and filling the pan with a layer of sand. The insulation layer was the size of the oil pan. These pans are not expensive at auto parts stores. The mat can't be tiny in relation to the pan, but you can certainly double the heated surface this way.

[Orchidtinkerer]

estacion, feel free to do that at home but I feel what you have described is a fire risk.
Heat mats can heat up, trapping the heat can create hot spots that can get hot enough to burn the mat, there is no sensor inside the mat to stop it overheating.
I have never managed to burn a mat and I place pots and everything else on it but I have heard plenty of people burning a hole into their mat - polystyrene on one side and a pan of sand on the other would be the best way to try.

Sand is highly insulating and would prevent the heat escaping.

[nuriko1set]

Originally Posted by Ray

One like THIS is what you're looking fpr

thank you Ray! I am ordering it now!

Do you all put it underneath the pots? what if I put it like an enclosure (fence) around the pots instead of underneath it? Does anyone have unique ways of placing these mats? I'm trying to keep my airy, so there's air flow. Thank you!

[WaterWitchin]

Under the pots, Nuriko. The purpose is to provide extra warmth for the medium and root zone.

[Orchidtinkerer]

I know this thread asks for a heating pad.
At the time I didn't answer it too well.
To be honest for the purpose a heating pad would not do much.

A heating pad is only effective when the heat can be trapped, so in a seedling propagation tray is what plant heat mats are designed for.

They are designed to heat 10cm above the mat.

If you have a 20cm pot and a 40cm Cattleya on top a heat mat will raise the temp for the plant by about 0.1 degrees C

The next step up would be a reptile heat mat which are designed to run hotter than a seedling plant mat.

But even they cannot raise the temp in a room enough to make a difference.

The next step is a retile heating cable but I've never bothered with them as you would need to run a cable all over.

The next step is a greenhouse tubular heater - I have heard they can be hard to find in the us - it can be hard to find a decent one in Europe too but Amazon usually sells them.

Next step is a portable space heater but they start to guzzle electricity and will heat the entire room.

It depends how much the temperature needs to be raised by.

[camille1585]

Originally Posted by Orchidtinkerer

I know this thread asks for a heating pad.
At the time I didn't answer it too well.
To be honest for the purpose a heating pad would not do much.

A heating pad is only effective when the heat can be trapped, so in a seedling propagation tray is what plant heat mats are designed for.

They are designed to heat 10cm above the mat.

If you have a 20cm pot and a 40cm Cattleya on top a heat mat will raise the temp for the plant by about 0.1 degrees C

The next step up would be a reptile heat mat which are designed to run hotter than a seedling plant mat.

But even they cannot raise the temp in a room enough to make a difference.

The next step is a retile heating cable but I've never bothered with them as you would need to run a cable all over.

The next step is a greenhouse tubular heater - I have heard they can be hard to find in the us - it can be hard to find a decent one in Europe too but Amazon usually sells them.

Next step is a portable space heater but they start to guzzle electricity and will heat the entire room.

It depends how much the temperature needs to be raised by.

Actually, the purpose of a heat mat isn't so much to warm the air around the plant or seedling, but to warm the root zone. The optimal soil temperature for germination of many common plants is in the 20-25°C range. The dome on the seedling trays is more for humidity than heat retention, though that is also important.

For established plants, increasing root zone temperature will stimulate root growth, and most commercial potted plant growers will use bottom heat (either in the form of pipes of hot water under benches, or in the sand under the ground tarp.). The botton heating will warm the pots/substrate and reasearch has shown that by increasing the root temperature, root growth is stimulated and plants can continue to have optimal growth at a lower air temperature. For professional growers this is a huge saving in heating costs as bottom heat is much cheaper than heating air. This works quite well, though it not meant to compensate for extremely low air temps compared to the optimal range.

It could very well be that the more airy bark substrates that orchids are grown don't conduct the bottom heat as well as peat based substrates, but I still think that heat mats serve a purpose, and this could be tested by taking temperature readings inside pots.

[nuriko1set]

Originally Posted by WaterWitchin

Under the pots, Nuriko. The purpose is to provide extra warmth for the medium and root zone.

thank you waterWitchin! I didn't know if the warmth was for root or stem! Knowing it's roots makes more sense!

---------- Post added at 09:49 PM ---------- Previous post was at 09:45 PM ----------

Originally Posted by Orchidtinkerer

I know this thread asks for a heating pad.


They are designed to heat 10cm above the mat.

Thank you Orchidtinkerer for making so much effort to answer my questions! I think maybe 10cm might be enough? I think it'll be helpful to heat the root zone up to around 70 F. My overall temp at home is around 65, a bit chilly even for me, I'm sure the plants are not happy with that.

---------- Post added at 09:52 PM ---------- Previous post was at 09:49 PM ----------

Originally Posted by camille1585

Actually, the purpose of a heat mat isn't so much to warm the air around the plant or seedling, but to warm the root zone. The optimal soil temperature for germination of many common plants is in the 20-25°C range. The dome on the seedling trays is more for humidity than heat retention, though that is also important.

For established plants, increasing root zone temperature will stimulate root growth, and most commercial potted plant growers will use bottom heat (either in the form of pipes of hot water under benches, or in the sand under the ground tarp.). The botton heating will warm the pots/substrate and reasearch has shown that by increasing the root temperature, root growth is stimulated and plants can continue to have optimal growth at a lower air temperature. For professional growers this is a huge saving in heating costs as bottom heat is much cheaper than heating air. This works quite well, though it not meant to compensate for extremely low air temps compared to the optimal range.

It could very well be that the more airy bark substrates that orchids are grown don't conduct the bottom heat as well as peat based substrates, but I still think that heat mats serve a purpose, and this could be tested by taking temperature readings inside pots.

thank you for the information Camille! It's good to have the confirmation of root and substrate heating is effective! I noticed a lull in growth of some of my orchids, mainly one Phal. The Cattleyas seems to be doing ok. This further confirms my need to raise the temp. a little bit for the plants!