Incoming arctic blast

[jesse3489]

Is anyone else making preparations for this arctic blast in the beginning of January, I only have a poly tunnel to put my trees in and the expected temps are supposed to be around 4 degrees without wind chill. I have supplemental heat in the poly tunnel and I hope it is enough to battle the what looks to be a solid week of below freezing temps with highs in the 20s. I added a layer of plastic on the inside, should I be worried?

 

[Brian Van Fleet]

Depends on what you’re trying to overwinter.

 

[A. Gorilla]

No.

 

[jesse3489]

Depends on what you’re trying to overwinter.

Ive got some tridents and some collected trees I'm trying to keep above freezing.

 

[bwaynef]

I'm looking for a bit more reliable information right now, but I'll say that it looks to be hitting during deep dormancy which is pretty good for us. I'm usually a few degrees warmer than WNC, but I doubt I'll be doing much more than dropping plants* to the ground. If it were in mid-late February or later I'd probably be making arrangements for the greenhouse/garage.

Also, did I meet you @ Green Thumb a few months back?

*At 20ºF I shelter a true olive. At 40ºF I try to shelter a couple ficus that I haven't bothered to throw out. (The past SEVERAL years they've actually frozen before I could bring them in. I shelter them but they don't do anything until May-ish.) I've got a couple gardenias that I'm trying to work out their cold-hardiness, but 20ºF is about where I'm comfortable with them.

 

[jesse3489]

That's a very good possibility! Did you go on the dig or were you buying a tree?

 

[Dav4]

The tridents won't mind if they're dormant and the roots are mulched. You might want to move the collected trees to a garage for a few days, unless you can provide bottom heat that'll keep the root zone above freezing.

 

[rockm]

Ive got some tridents and some collected trees I'm trying to keep above freezing.

The tridents will be fine mulched in the ground over their pots an inch or two. Done that with mine for going 30 years here in N Va. they’ve seen 0 F and bit below a few times in that period. Your collected trees will most likely be ok with this treatment too provided you didnt collect them this fall. If you did then you now understand why fall collecting is not a great thing to do. Best thing for recently dug trees is to get them into an unheated shelter like a garage.

 

[bwaynef]

That's a very good possibility! Did you go on the dig or were you buying a tree?

I don't remember what else I had that I was working on, but I was repotting a bunch of gardenia shohin-wannabes (for the first time in several years) at Green Thumb that day. Ring any bells?

Also, just watched a couple broadcasts about this winter blast: Looks like I'm going to skate thru mostly unscathed. *JUST* north of me are temps (<20ºF) that would have me a lot more concerned.

I think mulching tridents would probably be all the protection they'd need. If you're nervous about the recently-collected trees, incandescent Christmas tree lights put off enough heat to matter. They're better at warming space rather than roots though.

 

[rockm]

FWIW. supplemental heat isn’t necessary unless you get more than two or three weeks of sustained cold. For such short period a deep mulch pile will keep things adequately “warm.” Adding hit and miss heat sources can wind up being useless or push trees out of dormancy if they’re in an enclosed space.

 

[coachspinks]

It is still too far away for me to make any real preparations. The news of the possible cold did remind me I meant to buy some plant blankets. Not necessarily for bonsai but for other landscape plants that get bitten by temps in the teens.

 

[The Barber]

I keep my trees on the ground mulched in, but more than anything I keep them protected from the wind. Wind chill definitely can effect your trees the same as it does us. Wind chill can significantly increase the risk of frostbite on us, even at relatively mild temperatures if the wind is strong enough, same goes for any other living organism. This is why cold frames etc are good, the temperatures are generally similar to outside, but it gives trees the needed protection from the wind. You don't want them closed up too tight or daylight sun may cause your poly tunnel to warm up like a greenhouse and risk breaking dormancy, all you really want is for it to be a wind break. Mulched into the ground, the ground will keep the roots warmer than the ambient temperature and work as a heat sink. Unless you have trees not suited to your USDA zone then they should be just fine. One of the biggest reasons native species are some of my favorites is I never have to really worry unless it's a long period of sub zero temps, they are already suited to the climate here.

 

[Gabler]

Over here on the east coast, we already had temperatures down to 0ºF, and everything in my garden is fine. Setting the pots on the ground raised the surface temperature by more than 10ºF. Today it was in the 60's so everything got a drink.

 

[Paradox]

My tridents have also seen below freezing on occasion.
The first couple of weeks in December they got below freezing almost every night.
There are people that have grown then in Michigan.
Should be fine as long as the roots are protected and the rest protected from winds

 

[rockm]

Fwiw I’ve grown Texas and Louisiana collected trees here in N Va for decades as well as trident maple. No supplemental heat just on the ground and mulch. Cold frames can help but my big collected Deep South trees are too big for that. Biggest issue I’ve had (and this is only in the last ten years or so as winter temps have been one more erratic) is trees breaking growth too early. Too warm followed by deep freeze in lat Feb/early March.