I made a big cut on a Japanese Maple still in a nursery container back in November. It bled for quite some time, so I wanted to give it some extra winter protection since I live in Michigan (zone 6). I let it experience a couple light freezes (low 30s/upper 20s), and then I brought it into a north-facing 3-season room in our house. The room has stayed pretty consistently around 40-45 F. Is that too warm for sufficient dormancy for a deciduous tree like JM? What about for trees like JBP or Coastal Redwood, which I know donāt like very cold temps?
My guess is that 40-45F (4.4-7.2C) might be a bit warm for optimal Japanese Maple dormancy since they are a mountain tree. Can you set it against an outside wall and put a blanket over it to reduce the temperature a little? It is probably good for Redwood and might also be a little warm for Japanese Black Pine. One year of less than optimal dormancy will probably not cause any real issues, but several might. On the other hand, someone in Singapore posted on another forum about buying a Japanese Maple there and the average low in Dec./Jan. is 73F/23C and those are coldest months of the year!
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Thanks, Marty. Thatās kind of what I figured. I actually started just shuffling it in and out to keep the temps down. That room gets pretty cold at night, and I keep it near an exterior window, which stays a full 4-5 degrees colder than the interior of the room, so lately the tree enjoys pretty consistent temps between 34-38.
Zumbido,
There are hundreds of JM cultivars. Varieties have hardiness ratings all over the map. Ergo, their requirements for dormancy vary as well. The key is to talk to a JM grower about what varieties are suited for a 40-45 degree winter environment and buy a specimen of that cultivar. For the cultivar you already own, ask the grower what the optimum outdoor temperature range is and try to provide that environment for it. Talk to a couple of growers. Check the web.
I have a question on winter dormancy. In the winter care stream at 45min Ryan asks why a pine growing in Texas will die. Answer: because of carbohydrate exhaustion, which takes 3-4 years. It will continue to use carbohydrates (āWeāll call it sugars and starchesā he says) but it needs a break from that as it is a species geared towards high alpine growing. But why does it need that break? It would also continue to photosynthesize so it would also keep on generating sugars and starchesā¦
Are carbohydrates the same as sugars and starches? Why exactly is winter dormancy essential for health? I know it is needed but feel I donāt fully understand why that is.
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I am not a expert
My GUESS IS THIS.
Each year without the proper WD period the tree gets weaker and weaker.
What pushes spring growth is the STORED carbs,sugars,starches.
If it lacks the requirement of WD the next year it is weaker so it creates and stores less sugar and starches
Each year it becomes weaker and weaker until it burns out.
It never gets healthy again because it lacks it required cycle to create health so it gets weaker and weaker until it burns out.
By keeping it warm all the time you are requiring it to work 24/7 365
Can you do that? Chain yourself to a treadmill, get a restricted diet to limit growth and see how many years you last, burn out is burn out and trees are living beings already stressed because we limit growth, prune excessively, restrict food, do major surgery every few years, etc, etc.
Sure there is going to be a more scientific answer, about carb use and storage and I look forward to to it..
Just imagine how miserable the life of a bonsai is from a trees perspective..
They donāt want this, we force them to behave according to our rules.. So when you change the natural cycle by growing a tree in the wrong climate you either create the climate nature demands such as a/c or cold storage or eventually the tree or plant gets weak and dies.
Buy a tropical plant at Home Depot and put it outside in a Maine winter, it wasnāt adapted by nature to that environmental stress so it dies..
Just my guess canāt wait to see if someone smarter answers.
Good luck
Carbohydrates are a broad range of organic compounds based upon sugars and sugar derivatives and are therefore composed almost entirely of carbon, hydrogen, and oxygen. The simple sugars can be joined together in a process called polymerization to form more complex carbohydrates. if you combine 9 or more simple sugars you get a starch or a non-starch polysaccharide such as cellulose. Our trees store energy as various carbohydrates and build their structure from cellulose and related compounds.
True. I also could not run endlessly on treadmill, even when being fed. The difference between stored resources and energy generated āin real timeā trough photosynthesis, was new to me and makes sense.
Thanks for helping me understand!
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I had to read that a couple times. I like!
So, the result of photosynthesis are āsimpleā sugars which can be combined through polymerisation to form all kinds of carbohydrates that the tree stores to push growth later.
Is that the gist of it in one sentence?
Thanks for explaining!!
Yes, that is a very good one sentence summary.