OK. Last year I wrapped my in-ground figs like this and despite the mild winter we had, this tree died back to the ground. As you can imagine this had been keeping me awake at night.

A few days ago an idea came to me that was inspired (I think) by Johnparav and his glorious Figloo. Also I read somewhere where people do something similar with palm trees in cold weather.

I went to the local Home Depot and picked up one of these:

Only 30 watts when it's on

 


Built in thermostat that switches on at 0 C (32F).

I unwrapped it and luckily I did. It had been pushed way off to one side against the house wrap I was using to cover it.

 

 
 

A few layers of burlap so it can’t get too warm and around the tree the cable goes.

 

Follow up with a few layers of fiberglass pink and some stakes to keep the tarp from squishing the insulation

  

Finished with tarps and some mulch at the base and topped with a stylish hat.

I’ll follow up on this post in the spring for the big reveal. Fingers crossed it’ll be ready to go with no die-back, and that it's not a roasted fig tree…..

I left the others just covered as usual with house wrap and leaves over burlap.....We'll see how they do this winter.

It comes with a thermostat built in. It only comes on at 0 C (32F). I ran it and touching it you can't even feel the heat. So it shouldn't break dormancy.... In theory.... Also why I put some burlap between the tree and the cable.

As much as I don't want to find out...I wonder what would happen if it broke dormancy in the dark all wrapped up like that. Or if it could in the dark....Hmmm

Perhaps I should install some refrigeration? :-)

Great job Joe!

LOL! congratulate me in spring if I don't uncover a Fig-B-Cue

Great idea.

Is the thermostat under the pink insulation?

Have you considered burying that tree.

I'm curious about this method. I've also seen where Christmas lights were used instead of heat tape. Basically the same theory. How old was the tree when you put it in the ground? Is this the same tree that grew back from the root? Young trees are certainly more vulnerable to the cold than older ones. I wait 2-3 years (a minimum of 2 winters) before planting my figs in the ground. If this is the same tree than the wood is less than 1 year old. I can't think of a better way to protect a young tree, but as the tree gets older and stronger it may not be necessary. I would think it would be overkill. I've come to believe that a minimum temp of 20 degrees is just fine for most figs. You need to keep the decicating wind off of the tree by wrapping it, but it should not need much more than that. Especially as the tree gets older and stronger. There are certainly exceptions, but try not to plant those border line varieties in the ground.

The only problem I can think of is there may be an issue of the branch of the tree needing water over the winter and the root being frozen and unable to provide it. I've seen this problem many times with newly planted evergreen trees. There are not enough roots to provide winter moisture and the tree ends up with freezer burn. You should be ok though. It looks like you have plenty of mulch around the root system. There is nothing more that you can do. Good Luck! Looking forward to the update next spring.

Nice job .

John

Oh, it was also asked. The thermostat is in there under the insulation. It's built in to the cable about 2' from the plug where the leader meets the heat line.

I think that it is good idea, Since Swap on heating cable have build in 0C thermostat on power cable end, it works better than Xmas light, Most important, It is safer.

I was thinking about testing I'm ground trees cut small like Herman does in a greenhouse. Dig down 6 feet and build an insulated foundation. Double walled greenhouse. Only heat it at 32°F . The frost hangs out around 4' in my area rarely going a little lower but never past 6 feet. I believe that if the foundation was poured right it could work. 8" concrete, 2" foam outside, 4" inside foundation wall. I am in zone 3b so it would need to be well developed. My problem wouldn't be if it could work, I believe 100℅ that double walled greenhouse, air circulation and insulated foundation would work. My question would be the heat bill even heating only 32-40°F. Long term project ideas.

Good stuf, I think he is onto something here. posts like this should be our goal.

It would be good if you could note the electricity charge on the device- maybe connect it to an amperage meter-hour or something and see how much it uses untill spring. IT would also make you sure that the device is fail-proof.
If properly mulched and covered i guess even taller trees could be covered with one wire as the heat dissipated upwards.

The thing we do as Toronto area fig growers.

Here's to a short mild winter for us all. I look forward to the results.

This got me thinking about the ice melting wire for roofs. The roof wire comes in long lengths up to 200ft. The roof wire would be good for wrapping multiple trees with one wire.

Thanks Elin. I did some serious research firing a few years because I was interested in producing citrus in greenhouses up here. There are geothermal systems out west that work well but they run about 20 grand. Depending on how you go about the work the system like I described about should be under 10,000; 12,000 at most. But this is assuming you buy a 60-90 foot winter ready greenhouse, the bigger the house the more concrete money. (And I'm rubbish at carpentry). A greenhouse that big is usually 6,000 or so, the. There is heat system, and crete. You may well be able to put a regular hoop house on an insulated foundation double walled plastic and run a fan down the middle as well. Snow load is an issue up my way, but in warmer comes that's less of a problem. Obviously a hoop house is much cheaper than wood framed greenhouses. It all depends on your cold, snow load, and the amount of work you intend to put in all winter. If you intend to make money off the house, it's worth the investment. The only thing you can't skimp on is the concrete. There was a test done on coastal Maine z5 they planted 5 or 8 (don't recall which) varieties in a hoop house, single layer, no heat, no covering or protecting trees. They nearly all died to the ground, except RDB which only half died. All but one came back and they planted several of each. When I looked at their list I laughed since it certainly wasn't "the most c
old hardy" as they claimed. Personally I would dig the foundation first, then try with a hoop house. Better to spend 800$ on the top housing and try before erecting a 5000$ + structure for nothing. Another advantage of the hoop house is you can peel the plastic off in summer and let those babies get BIG.

It will be when I have 200 trees in the ground :-)

Seriously though....This will probably end up being more like $5 per year per tree. It's those February nights that seem to be the tough ones.

If this goes well I plan to make panels out of rigid foam insulation so I can re-use it every year and build a box around....That or used walk in refrigerator insulation panels... Even found this on Kijiji really cheap. would work great:

http://www.kijiji.ca/v-renovation-other/oshawa-durham-region/subflooring-insulation-insulation-panels/1199364418?enableSearchNavigationFlag=true

The cable is really interesting, especially if you were growing root crops in winter greenhouses. For me, even if I protected just the roots and covered the top of the tree I would likelt lose all above ground wood. At least I'm a greenhouse I could prune them to less than 3 feet tall each year for San Pedro and single cropping figs (or sacrifice Brebas) and protect in a greenhouse. All the otgers would be kept in container culture in an insulated barn. Just interesting to consider ways to sustain figs for production in cold climates. It may not be feasible financially, and I'd not l dig up, pot up again and use the greenhouse(s) for spring head start and fall ripening.

here's the palm tree example

 

I found the Wrap-On catalog https://wrap-on.com/

It seems they have a lot more than what's on the shelf at home depot, including many lengths of heating cables from 6 to 200 watts, control units and some purpose built soil heating cables called "Gro-Quick"

They also have these "Pipe-Guard" cables that you can buy in spools and cut to size...

it is warm and cozy for the tree.

I am thinking of heavier wrap/( vertically filled with dry soil) and not using heating resources.