I think trying to heat the ground under the palm is a waste.

If the ground gets cold enough (with a boatload of mulch over your palms)
to freeze,you cant grow palms there anyway,I think putting heat tape around the roots would
just dry them out(worst case senario)....I have seen the temps around my Washy @ 4" be 33F to 34F
when I peeled back the mulch in spring-no harm done.

As the roots spread out though,you do need to spread mulch over a wider area,this would probably
not effect Trachys to much but Washys roots will die back to the trunk if damaged-the bigger they get
the more(potentially)the roots can get pinched off by the cold as they reach out from the palms with age.

As the roots spread out though,you do need to spread mulch over a wider area

Or a wider "circle" of C-9s.

Does anybody know if Washies, for example, have "pancake roots"? or do roots tend to stay narrow and go straight down?

I've seen pics of older Trachies and Phoenix being dug up.
Phoenix roots are really fibrous, supposedly they can take a very harsh root pruning.
My own CIDP is proof of that, halfthe roots broke off when lifting with the tractor. 😕

Always surprised how narrow a rootball is taken with those two, but then again, no idea if survival is iffy (except with my Phoenix).

Barb

Barb, how is your CIDP doing? I'd be willing to try one of those down here in Kansas, but first, I'd like to know how they do up further north;)

My CIDP's is in a garbage can pot 😆
Never been in the ground.

But I have to make a decision soon...too many years to keep it that rootbound.
And they do love a 50% root pruning...well, maybe not LOVE, but it survived losing 50% of its roots.

Barb

Jim, I think your right about heat tape around the root ball maybe having a drying out affect. Thought that this year with the super cold we had(worst in 30 years) and lack of snow. Since I have so many palms with heat tape around the root ball, this Winter I will only plug in master cord to them all if temps dip below 0-5F otherwise will just use more mulch. Heck, in the fall the box stores almost give the stuff away to avoid keeping it around over the winter, plus I'd be buying it in the spring anyway since I use so much of it in my normal landscaping.

Good time to adjust the winterization plan...

When you think about how much mass the soil has it seems unlikely the temp would go up much...
soil is not a great conductor of heat...

I think some 2" foam would need to be made into an underground box with the heat tape at the bottom.
Maybe this way you could actually keep a warmer pocket around the palm....eventually the roots would find their way out.

Keep in mind the heat tape has it's own built in thermostat(at least the ones I use do) and it's located just a few inches from where it plugs in so it is inside the protecting itself(in most of my in the ground palms) so really, as long as the christmas lights inside keep temps in the say upper 30's at least, the heat tape won't come on anyway so it's really a second tier type of protection for really super cold times.

That being said I had a nice Needle palm in the ground from Jungle Music for a couple of years. Planted on the South side of my garage, I would only put a 1/2 plastic industrial barrel over it to protect it from cold winds. Usually I didn't even cover it, but if we had say freezing rain coming I have 2x2 ft plexiglass I get from work that I would just lay over the top to keep it dry. I did plant it with 6ft of heat tape though and thermostat was out in the elements so would naturally come on(indicator light) so I knew it was working. It sailed along for two winters slowly growing and looking good until this past super cold winter and I thought I would do it some good and I added 1 string of C7 christmas lights inside the 1/2 barrel when temps were going to drop to -15F.

The very next day..I looked and the fronds had all turned brown...dried up. 🙁 It wasn't until later in the spring that I found out that Needle palms LIKE lots of water and I had thought different the whole time and only let it get water when it rained. That factor, combined with the fact that we had almost no snow this winter...just severe cold helped it along to it's demise.

Learning from mistakes, I bought a beautiful 2 gallon Needle Palm from Steve Anderson and planted it close to first spot, but further out from the house so it gets more rain water...along with additional that I give it, plus it won't get as baked by the sun like the first one did. I did not however bury heat tape with this one. I will protect it with a frost cloth and the 1/2 barrel this winter at least to help it along and maybe have better luck. Pic attached. The little palm in the picture is a Chinese Fan palm that I've had in the ground for a couple of years that only gets very minimal protection at best....yet still comes back. No, it won't get big happy fronds like when I first got it as our season isn't long enough but so far...since we've had a warm and wet spring it's looking the best it ever has. Love these palms for their toughness.

Sorry pic is so dark, storm clouds were rolling in this morning when I was out taking the pic.

Beautiful needle, nice size.. i protect mine covering it only mine is three times smaller, no heat but winters here are milder and little shorter than Can. northern Am. etc. this is zone 6-7. Yes it likes water and semi shaded position, in winter soil has to be dry.

This new location it will get 1/2 day sun. Before the one that died was planted just to the right of the down spout in picture which is pretty much full sun, and was closer to the house and the eve of the roof kept it from getting some rain. New one is planted further away from house so will benefit from any rain. My old one was probably pretty dry going into winter anyway so I'm sure it was a combination of a few things that killed it.

Sounded like it overheated with the X-mas lights...

Always good to have one remote sensor inside the protection to see
how the temps fluctuate...or a T-3 thermocube...about the same price...
but the T-3 cant tell you if your palm is overheating in the sun.

I had the same problem with my 5 feets Needle palm. I used C9 with T3 in the mummywrap method. When i toke off the protection, it had all the outside fronds dried, but the Inside fronds was green. After 2-3 weeks, it became to dried completely, i don't know why. Never the temp. Inside the protection was over +15c. But i think the C9 was to hot for the leaves and shock the palm 😕 ..
Mike used a 23 watts CFL with T3 and his Needle was better than mine this spring. Maybe its the way to do. With avoiding the leaves to touch directly the heat source like C9 or CFL bulb.

Ben

Went ahead and bought a small Butia Eriospatha from Steve Anderson and planted it in the ground. Will get a lot of sun here, and should be easy to protect. Hopefully planted early enough in the season(6/28/14) where it can root in a bit before cold weather hits. Is right next to one of my ponds, so if I can keep it alive over the years should look really nice there.