Coldest allowable winter temperature.

[jkd2572]

I have always heard a wide range of freezing temperatures that you should allow non tropical trees to be out in. We have very mild winters here in the part of Texas I live in. I have always been confused on how low I can leave them out. Every year I take all of my deciduous trees into the garage. After the first light freeze. It is usually 28-31 degrees. I wait for all the leaves to turn brown and move them in. I leave all of my conifers and semi deciduous trees out all winter unless the temps threaten sub 25 degrees. I then do a dance of moving them into the garage then moving them back out to the benches when it gets back up above freezing. You have to realize we can have one night of freezing temps then not have another for two weeks. I'm starting to think I might be babying them to much. I wanted to know what some of you in zone 7 do. Other zones input is welcomed. I have listed the different type of nontropical trees I have below to give you an idea.
Black pines
White pines
San Jose junipers
Shimpaku junipers
Chinese junipers.
Bald cypresses
Trident maples
Japanese maples.
Chinese elms
Korean hornbeams
Crape myrtles
Hollys

 

[Brian Van Fleet]

In this Zone 7 climate, my trees go under the benches around Dec. 1st until mid-March. They're mulched in with pine straw raked up from the yard, then I put up a low fence to keep out critters (dogs, kids, etc). A wood fence runs North to South along the west, and very little wind or sun gets in. The goal is to minimize temperature fluctuations. When they're mulched in, it rains enough that they really don't need to be watered.

I have/had the same trees you listed and this has worked well every year, and at times we've had temperatures for a couple weeks dipping into the low teens.

Here is an older photo.

 

[jkd2572]

Nice to have pine straw readily available. Do you not have insect problems Using this method? if so do you pretreat them with something before putting all that debris on them?

 

[Brian Van Fleet]

Never had insect problems overwintering this way. The trees and area are treated for a few weeks prior to putting them away. I use malathion on the area and trees, then lime sulfur before they go under, and neem oil occasionally throughout the winter.

Debris isn't an accurate description of what is used, it's fresh and "clean", probably better than what can be bought in bales at Lowes.

 

[cmeg1]

I have been wintering my JBP in deep cold frames(like one or two years).The picture below shows the two I made.They are about 2.5' deep with gravel botttom.I was taught by my pines book that they do not photosynthesize below about 36 degrees F or so and do not need light then.If it starts to rise above that in my cold frame ,I actually bring mine out in sun.I can bring them out in around 6 minutes(yes,I timed myself).This year I am going to possibly get a lift-out basket fabricated,Maybe not though.It get's to maybe 10 degrees F or less in my winter 7a.My frame drops to maybe 27 degrees at coldest,but in very distinct layers cause' of the still air.The bottom of the pots always have dew on them.It is absolutely essential that coldframes are in shade all day.

 

[Paradox]

All of my trees are left outside to experience a few frosts. As temperatures continue to cool, I move them into my unheated garage in order of species cold sensitivity, and sometimes age and/or whether it had any root work done to it that year. My most hardy pines stay out all winter unless icing is forcast which is rare.

 

[Poink88]

Jeremy,

From your list & in your location, I think Crape & Holly are the only ones you might need to give extra care and only if you get a deep freeze.

It also depends on the variety you have. I've read some holly and crape that are thriving up north (relative to our location) unprotected.

 

[bonsaibp]

This is one of the many reasons to live in Southern California- no winterizeing except for putting the ficus and bougie's under a bench.