Deciduous tree dormancy?

[IdAu]

I was watching a video about propagating Willows and the guy said when temps drop below freezing in the winter, he puts them in the dark garage until spring.

Do they not require sunlight once they drop their leaves and go dormant? Is this true for all deciduous trees?

 

[darzuo]

Yep, no leaves means no photosynthesis, so no light required. That being said, if you're planning to overwinter in a garage make sure it's unheated and uninsulated. It needs to stay below ~40-45f else the tree may break dormancy. You don't want to tree to start leafing out in dead winter with no light.

 

[IdAu]

Oh man, that’s great news and sure makes my life easier. When people told me I may need to move my Japanese maple into the garage for prolonged below freezing temperatures, I thought I still had to move it in and out every day!

At the coldest parts of winter my garage does get a bit below freezing occasionally so it’s probably the perfect way to store them. Here I was trying to design some type of shelf for my upstairs window so I could move them in and out every morning at night.

 

[rockm]

True. Dormant deciduous trees don’t require light.

There is a steep downside to garages and enclosed overwintering spaces. though. Such shelter can keep temps too warm even at 35 degrees some species will begin growing. That can leave you with trees in leaf in February and no where good to put them. Growing in a dimly lit garage is not great and will weaken the trees. You have to be aware of the temp spikes and troughs I. The shelter. Trees begin growing after meeting their “chilling hour” requirements which vary species to species. Do a search on chilling hours for Japanese maples.

Watch this video. It’s short and informative done by one of the top U.S. bonsai professionals

 

[IdAu]

True. Dormant deciduous trees don’t require light.

There is a steep downside to garages and enclosed overwintering spaces. though. Such shelter can keep temps too warm even at 35 degrees some species will begin growing. That can leave you with trees in leaf in February and no where good to put them. Growing in a dimly lit garage is not great and will weaken the trees. You have to be aware of the temp spikes and troughs I. The shelter. Trees begin growing after meeting their “chilling hour” requirements which vary species to species. Do a search on chilling hours for Japanese maples.

Watch this video. It’s short and informative done by one of the top U.S. bonsai professionals

Thanks for the info. From what I understand, they won’t have to go in there very long. More of an emergency storage space for an abnormally cold week or two. I plan on keeping them outside most of the time.

 

[rockm]

Thanks for the info. From what I understand, they won’t have to go in there very long. More of an emergency storage space for an abnormally cold week or two. I plan on keeping them outside most of the time.

I wouldn’t count on it. Trying to game the weather guessing when to bring them in and out constantly over the winter and you can wind up with dead trees. I keep all my trees outside all winter under mulch in garden beds and in a cold pit. We have extremes of heat and cold here in The middle Atlantic states. I’ve had sub-zero F day in Jan followed by a February day in the 80s. Keeping trees in storage conditions with mulch etc lags those extremes (the covering lags cold as well as warmth so hot days in Feb aren’t warming pots as much as if they were exposed to open air)

Spring is the most treacherous time for overwintering since trees begin growing. A week long cold snap with temps below 30 will kill or severely damage trees that have began left unprotected. Once leaf buds have opened even a little the tree has lost 90-95 percent of its winter hardiness and ability to withstand frozen roots. Bigger pots may be less afffected while smaller ones an be killed outright if the soil mass freezes all the way through.

I lug all my trees (some are over 150 lbs) into the basement several times each spring to avoid that. You learn what works and what doesn’t in your area over time

 

[Shibui]

Spring is the most treacherous time for overwintering since trees begin growing. A week long cold snap with temps below 30 will kill or severely damage trees that have began left unprotected.

Please forgive my ingnorance of cold climates. When you guys give temps like 'temps below 30' does that refer to max or min daily temps?

 

[leatherback]

When you guys give temps like 'temps below 30' does that refer to max or min daily temps?

I normally talk about the lows for the day. Which in my climate means.. Most of late fall, winter and early spring I will have night temps drop below freezing, and daytime often popping to a few degrees above freezing intermingled with drizzle and rainstorms. Most years the wind turns east at some point, and we get permanent frost for one or more weeks continuous, where the highs do not breech 32F (and often these are the periods we dip down to -10c, -15c and occasionally -20C. Bad winters we have around freezing november to february, slightly warming up and in march we get an easterly for a week. That is when I get worried about my trees.

 

[Shibui]

We also tend to quote max temps in Summer and min temps in winter or Spring.
The reason for asking was the quoted 30 (F?). Assuming that's the min overnight temp and daytime is higher, that's similar to our Spring fluctuations, though we probably don't get a run for an entire week.
My experience is that my trees have had no problem with temps just below freezing as they start to grow leaves. I currently have tridents, Chinese elms and Cotoneaster with leaves opening and we've had frost with temps slightly below freezing most nights this week. No sign of dead trees or frost burnt leaves yet.
The only time I did have significant frost damage was a single night well below freezing reasonably late in Spring. Japanese maple leaves turned black but grew back a few weeks later. No other species affected by that cold night.

You are probably all aware that I don't have to worry about real cold temps, hence the reason for asking, but, given my trees cope with brief below freezing nights occasionally, I'm wondering whether some of the steps you guys go to are really justified?

 

[blackadam]

often these are the periods we dip down to -10c, -15c and occasionally -20C

Just checked temperature archives for my place, looks very similiar in last few years.
-10C is quite standard occasionally spikes to -20C
It will be my 1st overwintering of potted plant on my balcony so i maybe kinda overreacting..
I read kanzan cherry need to be protected in few years after planting so building coldframe - will be styrofoam insulated, should i also get mulch?
How You overinter your cherrry trees?

 

[rockm]

Please forgive my ingnorance of cold climates. When you guys give temps like 'temps below 30' does that refer to max or min daily temps?

Just saying that if the temperature are due to drop below 30 F at night consistently for a couple of days, (particularly if the daytime temps don't rise much above 40 or so during the same period) then you may have issues. My experience is that small pots will freeze through large ones not. I have lost trees to seasonal fluctuations when they're leafing out.

 

[Javaman4373]

My climate is probably similar to yours in Boise and I have overwintered my trees successfully. I put some on the ground in a sheltered spot next to a shed that has a 3 ft stone wall on two sides. I cover them with some old hay. They are shielded from the wind and only receive a little morning sun in that location. These are trees in large pots or grow boxes. Other deciduous trees in small pots I have put in my garage which is attached to the house. It gets cold, below freezing (32F) when ambient temps outside are very cold, but stays quite a bit warmer than outside. Some junipers, and white cedar trees I move into the unheated basement under a grow light on a timer for the coldest months, namely Nov to March and they have done well. Other than the junipers, my trees are mostly native trees I collected from our landscape. I have no experience with trident maples.

 

[gschup]

Just checked temperature archives for my place, looks very similiar in last few years.
-10C is quite standard occasionally spikes to -20C
It will be my 1st overwintering of potted plant on my balcony so i maybe kinda overreacting..
I read kanzan cherry need to be protected in few years after planting so building coldframe - will be styrofoam insulated, should i also get mulch?
How You overinter your cherrry trees?

Last winter was my first time overwintering potted plants on my open balcony on the 4th floor in Stockholm. I didn't bother building any enclosures and I was able to overwinter two cherry cuttings that rooted last year.

Some other species that I successfully overwintered without additional care: ginkgo, hazel, hawthorn, multiple pines.

In my limited experience, it was most important to get the plants out of wind and sun. I was amazed by how quickly my balcony would heat up on a sunny day.

Other than that, I mostly huddled all my plants together against the wall of my apartment. Last winter wasn't especially harsh, but we definitely hit -15C multiple times.

 

[Jetson1950]

You are probably all aware that I don't have to worry about real cold temps, hence the reason for asking, but, given my trees cope with brief below freezing nights occasionally, I'm wondering whether some of the steps you guys go to are really justified?

That’s the problem I have here in central Florida. May get lucky if we see three days a year with temps in the low 30F and I love growing Japanese Maple's. Guess that’s why all the snow birds from up north come here for the winter.

I’ve been told it’s not a good technique, but all my trees from the northern tear go in the garage refrigerator come December and go back outside in March. Those that only require about 1000-1500 chill hours go in the frig for Less time. They love it. Come spring they just explode in new growth. If I didn’t do it, the maples would live about two years and die because they don’t get their proper sleep time. The beauty of doing it this way is they get their chill time and I don’t have to worry about freezing temps for the ones in little pots. I just have to make sure they don’t dry out.

 

[Bonsai Nut]

At the coldest parts of winter my garage does get a bit below freezing occasionally so it’s probably the perfect way to store them.

Think about it this way - how many deciduous trees in nature spend a good part of the winter buried under several feet of snow?

 

[IdAu]

Think about it this way - how many deciduous trees in nature spend a good part of the winter buried under several feet of snow?

All of them. But my trees are in small pots, not in ground with far reaching roots that are insulated

 

[blackadam]

My balcony sticks from the apartment like that, get quite a lot evening sun - for now cherry seems like it
(potted in wooden 5 gallon box)
Its pretty windy here also (like mature tree breaking windy..) things need to be bolted or tied or they fly away
No garage and quite warm basement..
This winter was quite easy - only few spikes of -15C, but in previous years hit over -20 C and record for past 10 years was -26C
Few streets near some cherries planted in ground seems surviving and blooming, need to go there with a camera and take some pictures only thing i know those trees are floweing cheries
Definately i need wind protection and keep tree under 1meter height

I was able to overwinter two cherry cuttings that rooted last year.

I hope i get a lot of cuttings (and be able to grow some trees from them)
Yeah i guess im panicking a bit because 1st time and young tree ..
Boise seems also 6B-7A zone..

 

[Paradox]

Just saying that if the temperature are due to drop below 30 F at night consistently for a couple of days, (particularly if the daytime temps don't rise much above 40 or so during the same period) then you may have issues. My experience is that small pots will freeze through large ones not. I have lost trees to seasonal fluctuations when they're leafing out.

I concur with this and if you have wind on top of cooler temperatures, even in the 40s with dry winter days and new leaves = wind burned leaves

 

[bonsaichile]

Yep, no leaves means no photosynthesis, so no light required. That being said, if you're planning to overwinter in a garage make sure it's unheated and uninsulated. It needs to stay below ~40-45f else the tree may break dormancy. You don't want to tree to start leafing out in dead winter with no light.

And leave a door or a window open. Air circulation is important in wintet storage

 

[IdAu]

Back and forth back and forth....

I talked to the nursery right around my corner. He either puts all his Japanese Maples that are potted in the ground up to the level of the pot, or covers them about a foot over the pot edge with mulch and said they live.


So I figure if I do both I'll be extra safe. In the ground with mulch piled up.


The random spring thaws and freezes may require the garage it sounds like.