Well, earlier than I expected – Winter has arrived with a vengeance. I thought therefore that it may be time to answer a few repeat questions, and what you CAN do to offer degrees of protection to your beloved Bonsai.
Firstly with deciduous trees it is perfectly acceptable to place them in a garage or shed/workshop that is NOT heated. This will offer protection from freezing winds (acts like a blast freezer). It does not even matter if it is permanently dark as the buds/leaves that require light are not yet requiring any light.
This will help prevent severe freezing.
Covering with whatever you wish to use is OK but bear in mind that no matter what you use if temperatures stay at freezing then eventually the pot will be the same no matter what you wrap it in. Our trees have an in-built anti-freeze system and are much more resilient that we oft give them credit.
When daytime temperatures rise above freezing you have little to be concerned about. It is prolonged days and nights at freezing or below when trouble can erupt.
In almost thirty years I have not suffered any real problems. That is not to say I throw common-sense to the North wind and adopt a carefree attitude. No I most certainly do not.
This year I do have some concerns, as all of my trees are due for re-potting this coming Spring. It is therefore always worth remembering that there is only a pot wall separating the roots from the elements. Keeping them slightly dry during the Winter is also helpful. This whilst obvious frequently provokes a debate. I’ll still stick with what works for me and that is drier in freezing conditions is better.
You can bury the pots in the ground if you wish, personally I have never tried it so cannot comment further.
If your collection is of a size that you can easily move them, have a look around when it is next frosty or freezing in your garden, there will be one or two spots that enjoy protection, in that case move them to this area, it will benefit the tree/s.
I’m asked what about snow? Well, again personally I don’t worry, it does actually offer some insulation (think of the Eskimos and what they live in). In heavy snow I will remove some on lighter branches. I don’t want the weight of snow thawing breaking any fine ramification. Do it carefully and you’ll be fine. Some snow below.
More to come:-)