I'd like to know how to heat the root zone. I've used some heat mats but and underwelmed. What other products will heat the root zone?

thanks for any advise

There was a post previously about using Heating Pads. I tried them but it got to be alittle complicated as it took two pads per pot and made watering difficult. I bought these about a month back which has worked pretty well so far:

http://www.growerssolution.com/page/GS/PROD/heatmats/econcables

It runs in loop so I circled it around the outside of the root ball while ensuring the wires didn't touch or overlap. They are somewhat pricely but they have an auto thermostat that turns the cable on and off. So you just plug in and go. It has consistantly kept the soil temp right around 76 degrees. They also don't appear to run really hot which won't overheat the roots.

If you buy say 40 feet of cable do you wrap that inside a pot then dangle it to the wrap inside the next pot? I would assume when one buys 40 feet of cable you can wrap about 3 3-5 gallon pots. It obviously isn't trimmed per pot and then rewired. Or is each order of 24 or 36 or 40feet supposed to only heat one pot? Or can you wrap outside the pot too? Seems like an odd system to have to bury the cables unless you were repotting . . .

Any other methods to warm root zone?

So far I have:

1. heat mat (usually used for seedlings)
2. these cables
3. wrapping Christmas lights on outside of pot (not easy to fine non-LED type anymore)

I too am seeking the best answer for this, and would be interested in any commentary from the experienced folk. I'd love to find a way like this , but that doesnt cost $30 bucks PER container, and only one size option (rediculous).

My Current Idea:
[disclaimer - just an idea, not built or tested yet]
This is somewhat extreme, but something I am considering doing because I want to heat them year round in a cold area, and need a good, serious, long term, low operating cost solution.

Build custom heater pot shells that you then drop your planted pot into.

Buy small (1/8 or 1/4") copper tubing. Coil it, put in bottom of pot, ends coming straight out the bottom (not up over top). Ends have connectors. Then, arrange pots however you want, and link them all up with another small tube (plastic, whatever). Now run the line through a small on-demand water heater with a max temp of 70 deg or so. Set this up as a closed loop system with a pump and thermostat (with temp sensor in one of the pots), and bobs your uncle.

More detail: The idea is to use 2 pots. The outer pot would get pine bark or something insulative. an inch of Pine, then the copper coil. Then the inner pot. Then pine bark in between the pots to insulate the walls. Now you have a fully insulated pot with a copper coil under the inner pot, ready to heat the soil.

Issues: I may need to find a better insulator than pine bark. This would only work for drip irrigation. Gotta keep the pine dry if its going to insulate. I suppose I could just literally use spray foam if I was planning to make the dual pot thing permanent, but need to make sure there is good drainage all the way from inside to out on the bottom.

The theory:
You would be able to heat _just_ the soil of the container, nothing else, saving heating cost. Copper should not (in theory) leach into the pot since its on the bottom where the water exits.

Benefits:

-low cost, heat only the soil
-variuous sizes simply by adjusting pot size and coil to match
-literally like a "network" of potted containers
-ability to add as may containers as you figure the available warm water can handle

I am not an industrial engineer, just a creative hobbyist. I'm seriously considering building this by the end of summer unless someone tells me this is a dumb idea, or unless I find something that does something similar off the shelf. If this is a good idea, someone is going to take it and make lots of money and not credit me. Just give it a few years.

its an interesting idea Roachslayer although it sounds complicated. I was thinking more like heating the surface that all the plants sat on. This would be simple if they sat on a metal table but the idea of running tubing with warm water seems sound (could work under heating surface or tubes within the pots themselves.

I think copper would have to be completely separated from the plants/soil as even small ion of Cu+ can kill all plants. Seems plastic tubing would be a smarter setup - basically similar to aquarium setups . . .

But, your right at $30 per plant for heating its pretty pricey.

How about your idea with a pump, aquarium (water resevoir), heated water, and plastic tubing that runs through all the plants?

This is what we use.

http://www.deltatsolutions.com/gh/gh_heat.html#epdm_sd

It's easy to make your own.

turtleman, that is awesome. Thanks for the reference. How does this compare to simply using electric heat cord?

Yes, my suggestion was complicated, mainly because that is life with custom stuff when no off the shelf solution is good enough. I was going strictly for efficiency, given that I have to provide heat 9 months of the year. All ways of heating have their place, depending on the need. I was targeting heating per-container, and not outside the container (ie, not the table, room, or space). That makes way more sense for containers sitting outside, but needing supplemental heat. If indoors or in a greenhouse, I think a heated bench makes a lot of sense, and is indeed more simple.

With copper, again, thinking of efficiency. But even with it outside the pot that the plant and soil is in, it may be too close for comfort. Plastic tubing that has good thermal conductivity may be the way to go. Thanks for the suggestion.

I would love to add this Delta-T bench heater tubing to my bench. Meanwhile, still on the lookout for a good per-container solution so I dont have to become a mad scientist by end of summer

It just uses allot less electricity that a coil. All you really need to make your own is a water heater, circulation pump, poly tube, pressure tank (closed system ya know).. its a real simple concept.

For just a few plants you can use a water bed heater.

How about:

cheap fish tank, water bed heater inside, pump & tubing.

question is to wrap tubing on outside of pots or bottom? Use plastic tubing or copper for better heat transfer?

It seems its just the opposite of a water cooled CPU, too bad metal plated don't easily fit on bottom of these pots then hot water could go there exchange heat and recirculate back to tank for hotter water.

A few years ago I built a water-heater circulating system but gave up on it. There were a number of "issues". First, using 1/8 inch vinyl airline tubing didn't work.....not enough flow. Second, after wrapping each pot (on the outside) with larger tubing, I then insulated it and had to carefully lay out the multiple pots to make sure tubing wasn't kinked, or connections didn't come out etc. Then I had to check periodically to make sure that the water in the resevoir hadn't evaporated and that the pump was still running. It SEEMED like a real good idea, but for my home citrus farm it didn't work out.

LOL,

it seems like a more complex idea than it needs to be but I ordered a pump, submersible heater and 100' of 1/2 inch vinyl tubing with 4 extra Y joints. I plan to put the water into a closed system so evaporation shouldn't be a problem. I wonder if the 1/2 inch tubing is strong enough to sit under a pot (instead of wrapped around a pot).


Here's my idea for a new pot design - take the air root pruning pot but have channels between the air holes where a person can hook up a tube and pump water through it. In a way, it would make the pots water heating and water-cooling ready.

Good to know 1/8" was too small, no flow. I was thinking about 1/4" OD, but it sounds like that will be too small. 3/8" seems like a good idea. I also have 1/2" but I dont think I could coil it for any of my smaller pots. The real bugger seems to be locating cheap fittings or quick connects.

I am now also looking at how to perhaps place a "bladder" or small enclosed container (like an ice pack) at the bottom of the containers, again, hooked up to tubing to flow from pot to pot.

This thread could get very interesting.

I ordered a fountain pump, a submersible heater and 100' of 1/2 tubing, well see how it does. I was thinking of coiling the tubing in concentric circles under the plants but maybe some will be too heavy. Stay tuned for more fun.

I received the equipment to create a heating water tubing setup but decided to bag it. I have all my citrus under heating mats and measuring the temps they are doing fine, I did still have some WLD but not very much on any tree and I've gotten some new growth on all trees.

Couple of things of note to anyone that wants to try this:

* 1/2 tubing is really really big to work with (I've read 3/16" is too small to do much heat transfer).

* I bought a submersible heater 300Watt that is too large for most 10 gal buckets which means I'd have to increase the size of reservoir to heat (which could also mean needing a larger pump).

* thinking about it and if I had set the heater on a timer with lights and such water would be cold when lights first come on so heater would have to come on earlier to heat reservoir of water.

* I still think this would be a good system if tubing was inside plant containers.

* the more I thought about it its too much to maintain and watch - careful of evaporation because submersible heater can't get exposed. Concern about leak in tubing anywhere. Heater failure would then cause cold water to make root zone cold. Noise of system, timer issues, etc.


Most of what I bought will be going towards my new hydroponic project so no waste (aside from 1/2" tubing . . . ). This leads me to another question since I will be doing hydroponics soon, can I water the citrus trees with the discarded nutrient solution (about 150-400 ppm, pH about 6.0)? I've read in hydroponic books that the nutrient solution can be used to water houseplants, etc.

thanks,
Todd