Why not heat the soil in Zone 5

I now that sounds ridiculous but if someone has that one special tree that is subject to freezing why not embed a heat tape in the pot to warm it to what ever temperature that you set the thermostat to. I have never done it because I am in heat zone 7 and don't need it, but it is just an idea. So how did I get such an idea, well that come from my experience with aquariums, I alway used a heat tape or pad inside the aquarium to maintain the temperature of the gravel bed. We embed heat tapes bird baths to keep them form freezing so why not in a pot for a maple? I have alway wondered about that since I was a boy because this guy out on Rt. 33 installed all sorts of cactus that don't live here, or was thought not to live here, it was rumored that he ran hot water pipes under the ground to keep their roots from freezing all winter. I have no idea if it true or not, but his place is still there and it is truly a weird sight to see in Virginia. It will not hurt my feelings if no one replies to my post it was just a thought.

 

Maples, for one thing, need the cold to go dormant, so it's a bad example anyhow, but you'd end up (maybe) with fried roots, dried roots, and still maybe have cold spots. I think it's theoretically interesting, but not really the best idea. There are lots of ways to overwinter trees without doing that, and the point of keeping trees outdoors (at least in their own zones) is so they can experience the seasonal changes they need to. If you're thinking of growing tropicals, etc. up north, there are other factors besides the cold that would matter, not the least of which would be feet of snow packed down over months.

 

Yes, heat is used to amend mother nature but is not normally suggested or used. I have people in climates totally unsuited for Japanese maples. I am not aware of any of them using "heat" but they do protect the roots with mulch, bubble wrap, and all sorts of things to protect the roots from freezing as the roots do not go dormant like the tops do. My customers have had good success protecting trunks and limbs by spraying them with a copper fungicide and after drying spraying again with a anti-desicant to protect against drying out and not necesarily freezing as there is little if any moisture left in dormancy. We use heat in most of our propagation procedures as do many of the largest wholesale propagation nurseries. Snow is an insulator and actually provides heat so it is wonderful if maples are covered with snow. Only bad thing is rabbits or other rodents eating maples at snow line. Heat is fine if used appropriately and conservatively.

 

It won't need a lot of additional protection - just build a portable plastic greenhouse that you can put over the top of it when severe cold is forecast