My friends in Montana tell me they dig a trench about 6" deep, set the pot in it and fill it up with sawdust or straw just leaving the top of the tree exposed. Junipers are tough. I leave mine out on the bench all winter and we get down into the teens. Two winters ago we had one night of 11 F and the junipers were fine.

Jack R, Thanks for the response! I'll try digging the 6" trench. We are supposed to be in an El Nino cycle, so we can expect heavier than normal snows this year. This bed has good drainage and a half day sun so I think it'll be a good spot. It's also near the front door, so I'll see it as I come and go. Hopefully that'll keep me from neglecting it. It is such a cool plant and after lurking here I realize the effort that went in to creating it. It makes me want to take care of it properly. My inclination is to not fertilize it this fall or winter so as not to encourage new growth. I will probably consider repotting it next year. I have no idea what the root system looks like and no roots are growing through the screens in the drain holes so I think it's fine for now. Thanks for the input!
Barb

if you get alot of snow cover it in snow to block the wind
also ask the person where you got the juniper how to keep the juniper healthy over winter

Organic_mrbest, thanks for the tips! I'll do that.

You didn't say what species of juniper you have (procumbens?), so it's difficult to guess at what low temperatures it might tolerate. Certainly, frozen soil in itself is no problem, as long as the actual soil/root temperatures don't drop below killing lows. More on that if you're interested - just ask.

While your juniper won't technically go totally dormant (only quiescent), for all intents and purposes you can consider it dormant during the coldest months. If you move it into an unheated garage with no light and ensure temperatures are between 20-40* during its stay, you should be just fine. I over-winter at least 50 junipers of various species in a garage with only one small window, and that is covered by a shade & curtains. Just remember to toss a little snow on the soil from time to time to keep it from drying completely.

Al

Unfortunately I don't know the exact species, but it's blue, possibly a blue star juniper. I'll see if my better half can post a picture for me. We are very dry, less that 30% humidity and generally have lows in the 20's. Most every February we get a 10 day spell below 0. I do have to water my in ground junipers every month or so through the winter or they dessicate. (I think I need spell check). When we get snow fall it generally melts in a few days to a week at most. We don't have winterlong snow cover like you get in the midwest. I don't have a true garage that I use daily to park my car, I have several farm outbuildings and a barn. If I overwinter it in one of the buildings I'm afraid it'll get too cold, I'll forget about it and it'll dry out. That's why I'm leaning towards burying the pot. I think it'll retain some moisture better in the ground. I wouldn't think our winters are worse than yours in Michigan but you most certainly get more moisture than we do. I could send myself email reminders to water it, LOL! Without snow, how often do you water yours in the garage?

I toss a little snow on my plants as needed, which sort of depends largely on container size, but on average I would say that I 'snow-water' the junipers growing in bonsai pots about every 3 weeks & the junipers growing on in larger pots about every 5-6 weeks.

It sounds like you're still going to need to water, even if you bury it, so your plant will require due diligence on your part. ;o) Could you bury the plant next to the foundation of the house, on the north side, then mulch it heavily? If only one plant is involved, you could sink a bucket or tub with a flat top in the ground and put the plant in that and cover with a board to over-winter. There are lots of ways to approach it, including the trench mentioned upthread.

Even though junipers are hardy, they still don't like their roots being exposed to extreme cold. Roots don't all die at the same temperature, they die incrementally as the temperatures drop. While it varies by species, and genetically by individual plant within that species, all roots on the same plant don't have the same tolerance to cold.

These numbers may not be accurate, but it gives you the feel for what I'm talking about. We say that junipers are very hardy because they tolerate low air temperatures, but what about root temps? Most temperate trees, even in zone 4, never see actual 6" soil temperatures much below 27*, with 25* being unusual. This is true, even in bare field agricultural conditions.

We know that the finest hair roots - the ones that do the lions share of the work are the first to die. In many woody plants, these roots begin to die as soil temperatures drop below 25*. As temperatures drop further, larger and larger roots succumb to killing low temperatures. The point is - that many trees that SURVIVE are left with only the largest roots to support them because much of the rootage has frozen. These trees are slow to respond in the spring because they need to utilize stored energy to regenerate lost rootage before they can move sufficient water and the nutrients dissolved in water to support either growth or the flush of foliage that makes the food that allows the tree to grow (this, in the case of deciduous material).

So, while trees might survive at extremely low temperatures unprotected, we KNOW it is better for the tree, especially from an energy management perspective, if we give them protection that ensures actual root temperatures don't drop low enough to kill even the finest roots. For most temperate trees, that means we should strive to keep low root temperatures in the upper 20s at their lowest, and below 42* to keep them from growing until spring when we can get them into good light w/o worrying about frost/freeze.

Prolly more than you needed, but good info to have in the memory bank about cold-hardiness because the general application applies to all temperate plants.

Al

Al, not too much info at all! I appreciate the wisdom of those more experienced and your taking the time to explain it thoroughly. Thanks!
Barb

Freezing isn't a problem for us here but the information was interesting and very relevant to the original post. And knowledge to keep in the back of my brain when I trade with those in the north. Who for some reason are obsessed with something called "dormant". Below 42! BRRRRRR!!!
Tally HO!

If there is interest, I can expand on cold-hardiness/dormancy via a copy/paste job from other threads I've contributed to ..........

Al

Al, I'm interested! I'm sure I could learn a lot.
Thanks!
Barb

A little more. If you have questions .....

Commonly, each species of plant has a general range of cold-hardiness, but within species and cultivar, cold-hardiness is genetically determined. That is to say that a plant that is propagated from cuttings or tissue culture will have the same ability to resist cold as the parent plant. Plants cannot "develop" a greater degree of cold-hardiness by repeated or prolonged exposure to cold, even after 100 years (trees).

If we pick any plant at random, it may or may not be able to withstand freezing temperatures. The determining factor is the plants ability to prevent freezing of bound water. Bound water is the water inside of cell walls.
There are actually three kinds of water to consider when we discuss "freezing" or cold-hardiness. The water held in soil - When this water freezes, and it can freeze the soil mass solid, it doesn't necessarily kill the plant or tissues. Then there is free or unbound water, also called inter-cellular water - This is water that is found in plant tissues, but is outside of living cells cells. This water can also freeze solid and not kill the plant. The final type of water is bound water, or intra-cellular water - If temperatures drop low enough to freeze bound water, the frozen cells and the tissues they form die. This is the freeze damage that kills plants.

Fortunately, nature has an antifreeze. Even though temperatures drop well below freezing, all plants don't die. In hardy plants, physiological changes occur as temperatures drop. The plant moves solutes (sugars, salts, starches) into cells and moves water out of cells to inter-cellular spaces in tissues. These solutes act as antifreeze, allowing water in cells to remain liquid to sometimes extremely low temperatures. The above is a description of super-cooling in plants. Some plants even take advantage of another process to withstand very low temps called intra-cellular dehydration.

Any/all parts of your plants can stay frozen for extended periods or go through multiple freeze/thaw cycles w/o damage, so long as the temperature does not fall below that required to freeze intra-cellular water. If roots remain frozen, but temperatures remain above killing lows, dessication is the primary concern. If the tree is able to take up water, but temperatures are too low for the tree to grow and make food, stored energy becomes the critical issue. Dormant and quiescent plants are still using energy from their reserves (like a drain on a battery). If those reserves are depleted before the plant can produce photosynthesizing mass, the organism dies.

There are a number of cultural factors that also have some affect on the cold-hardiness of individual plants, some of which are length of exposure to seasonal cold, water availability (drought stressed plants are more cold tolerant), how recently planted/repotted, etc.

Al

Great explanation, Al! I'm sorry I didn't read this sooner, but I've spent the last 2 evenings in parent teacher conferences. My brain is fried! I will read this again once I'm rested and can ask intelligent questions. Thanks for taking the time!
Barb