Thank you very much friends.
Hello Judy,
I will try to explain.
First of all, you have to consider that I live in Belgium.
We have a temperate climate, but very humid.
For example, I haven't watered my trees for almost three months and they are still wet.
Here, winters are relatively mild, but in my region, it is not uncommon to have a week at -20 ° = -4 °F during the nights.
These -4°F weeks are sometimes preceded and followed by milder (more or less) 26.6°F frost periods, which means that the frost periods can last several weeks.
This is not a problem for trees in nature, because their roots go down low enough, but for bonsai...
I have a lot of azaleas (satsuki), they have an evergreen foliage, in winter, they need less water, but they still need it. Contrary to what we think, they are resistant to cold, but not to lack of water.
If the substrates are frozen for several weeks, they do not die of cold, but of thirst.
So I keep the temperature of the greenhouse frost-free.
Look, in this picture,
one year I had put all my trees under cover and that was the same in both greenhouses.
It's not very nice,
but all my trees were protected and that was the most important.
They stayed like that for more than a week without any problem.
The tables in the center of the greenhouse are made up of five galvanized metal grating panels, like the one in this picture.
I can put 1, 2, ... or all 5, which allows me to double the surface of the greenhouse to protect my trees when the cold periods are too long.
It is also very practical when I have to replace the insulation in the greenhouse.
Regarding the variation of the temperature due to the sun of the day.
If you look at this picture, you will see that two trees (liquidambar) have been planted in front of the greenhouse.
the advantage of the Liquidambar is that it gives me pretty colors in autumn.
They are on the south side of the greenhouse, which means that in summer and autumn, the greenhouse receives very little sun because their foliage protects the greenhouse from the sun. It only gets an hour or two of sunlight very early in the morning, which is great because it's coldest at sunrise.
Another point to consider is that the greenhouse stays with its insulation all year long, so the temperature remains fairly constant even when the sun is shining in winter.
That's it, I will present some trees on the forum, but I also have to write the continuation of the Shin, Gyo, So and share with you some pictures of my travels in Japan.
I don't know about you, but here in Europe we often caricature Japanese people with a camera, it always made me laugh. Until I made the trip to Japan.
I went there three times and I made more or less 6000 pictures per trip, that is 18000 pictures.
