Hello,

New to bonsai, I'm preparing my trees for winter in Vancouver BC Canada.
Do you have best practices for Japanese Black Pine & shimpaku Juniper, winter care?
Coldest temperature here approximately 10 degrees below zero Celcius.

That’s no problem to deal with it for either species.

If temps STAY at -10C for days, then you need a cold frame or some protection, particularly if it’s also sunny and windy at the same time: frozen soil means they can’t intake water, while wind and sun are causing transpiration, resulting in dehydration for the trees.
If what you have is “some days with night lows around -10C”, while during the day temps go close (or above) freezing point, those trees are more or less in their natural habitat and there’s nothing to worry about. Just in case try to place them in a spot where they can get light but not too much wind, if you can, but that’s about it...

Thank you Bofhskull.

BofhSkull wrote: That’s no problem to deal with it for either species.

If temps STAY at -10C for days, then you need a cold frame or some protection, particularly if it’s also sunny and windy at the same time: frozen soil means they can’t intake water, while wind and sun are causing transpiration, resulting in dehydration for the trees.
If what you have is “some days with night lows around -10C”, while during the day temps go close (or above) freezing point, those trees are more or less in their natural habitat and there’s nothing to worry about. Just in case try to place them in a spot where they can get light but not too much wind, if you can, but that’s about it...

I'm in Victoria and agree with the above. I keep my trees ON the ground, in sheltered, but exposed to rain and snow location. To keep the pots clean, I place them in shallow cardboard boxes obtained from Costco. I cover more sensitive trees' pots with leaves, or better yet, leave mulch with the layer of 2" to 3" thick.
One caveat: heavy snow may damage some of the branches. To eliminate this possibility, I place some of the trees under the benches. But keep in mind that ALL trees like to be exposed to sunlight in the winter.

Hi there, Thanks for starting this thread, is it ok if I hop in here and add to the topic? If not i will take my lumps and re-post after being scolded.

live in Ontario Canada where temperatures have been down as low as -20 Celsius ( -4 F) consistently for days. I know Juniper are best left outside but what kind of protection can i offer them in temperatures like this? I have been doing what you suggest is a total no no and have brought it inside. Supposed to warm up to about -5 tomorrow and could potentially transition it back if I know what to do. What kind of small-medium structure can i create to protect my young juniper? Thanks.

MattN wrote: Hi there, Thanks for starting this thread, is it ok if I hop in here and add to the topic? If not i will take my lumps and re-post after being scolded.

live in Ontario Canada where temperatures have been down as low as -20 Celsius ( -4 F) consistently for days. I know Juniper are best left outside but what kind of protection can i offer them in temperatures like this? I have been doing what you suggest is a total no no and have brought it inside. Supposed to warm up to about -5 tomorrow and could potentially transition it back if I know what to do. What kind of small-medium structure can i create to protect my young juniper? Thanks.

MattN, best advice is find somebody near you doing bonsai and copy what they do. You want to shelter them from harsh winds and you want to protect the roots from too fast freezing.

Where are you in Ontario? I just looked up Toronto and North Bay and they aren't anywhere near that cold.

Ottawa. Currently it is warming up. -13 with wind chill at the moment. I may have to. There are some people in Quebec and one nearby in Ottawa that I have located but the one here is primarily indoor in the winter and I wonder if this will be required. Only know of them via Marketplace and online media so am hesitant to push for help. Should just do it tho, thx.

Hoping I can find a way to do this as a hobby without pissing off my wife by cluttering up our house/backyard.

Apologies. I have hijacked this post. Stepping out.

MattN wrote: Ottawa. Currently it is warming up. -13 with wind chill at the moment. I may have to. There are some people in Quebec and one nearby in Ottawa that I have located but the one here is primarily indoor in the winter and I wonder if this will be required. Only know of them via Marketplace and online media so am hesitant to push for help. Should just do it tho, thx.

Hoping I can find a way to do this as a hobby without pissing off my wife by cluttering up our house/backyard.

Try ottawabonsai.org/