Does anyone overwinter on the bench?

[rodeolthr]

The OP is not in Washington state. They are in Washington DC/MD. I'm just south of them in No. Va. We have mild winters compared to Wisconsin, but harsh compared to Washington state. Lows can sometimes reach into sub-zero in bad winters. Normally nighttime lows are in the mid 20's in Jan. and Feb. They can go even lower for days on end. Duration of cold makes a big difference with overwintering, as well as only temperature. Exposure to prolonged deep freezes kills trees. Shohin and mame are usually the first to go.

A frozen pot is not a frozen pot. Depth of cold makes a huge difference. If that freeze is only into the mid-high 20's intracellular water generally doesn't freeze. Prolonged freezes below 25 F freezes intracellular water (water inside root tissue cells, as opposed to intercellular water between cells). That frozen intracellular water explodes living cells (like freezing a can of soda ruptures the aluminum as the content inside expand), damaging tissue or entire root systems.

Yes, I was just giving an example of what I do in my climate. When it gets down below freezing here, it can stay that way for 2 weeks and everything remains frozen solid. I'm originally from northern Wyoming, where at the time it was not uncommon to see temps of -40, so I definitely understand that there are varying degrees of cold and freezing.

 

[Deep Sea Diver]

The OP is not in Washington state. They are in Washington DC/MD. I'm just south of them in No. Va. We have mild winters compared to Wisconsin, but harsh compared to Washington state. Lows can sometimes reach into sub-zero in bad winters. Normally nighttime lows are in the mid 20's in Jan. and Feb. They can go even lower for days on end. Duration of cold makes a big difference with overwintering, as well as only temperature. Exposure to prolonged deep freezes kills trees. Shohin and mame are usually the first to go.

As a blanket statement is accurate….

Actually I lived just down the road in Dumfries for a number of years.

A frozen pot is not a frozen pot. Depth of cold makes a huge difference. If that freeze is only into the mid-high 20's intracellular water generally doesn't freeze. Prolonged freezes below 25 F freezes intracellular water (water inside root tissue cells, as opposed to intercellular water between cells). That frozen intracellular water explodes living cells (like freezing a can of soda ruptures the aluminum as the content inside expand), damaging tissue or entire root systems.

Here’s where the hang up always seems to appear.

The statement assumes a full freeze of a root ball is the only thing that will harm a tree. That there is a cut off where everything happens at once. That death is the cut off between healthy and unhealthy. Certainly not yet true. All roots on a tree are not equally hardy… and the ones that are least hardy are the ones that a tree needs most.

What is key here is keeping all the roots from being harmed, especially the feeder roots. (Tree death is over the top.) When this happens a tree prioritizes roort growth over growth in the trunk and branches (but not necessarily budding). This puts tree resiliency for upcoming work at risk.

cheers
DSD sends

 

[Deep Sea Diver]

I have hundreds of trees, from seedlings in flats to more developed bonsai. As I have no other place to put them, they are outside all winter long. For the past several years, they have routinely experienced extended periods well below freezing, as @Deep Sea Diver stated. A combination of not being here, and having nowhere else to go, makes me grit my teeth when I watch the weather forecast. But, for whatever reason, they always come through and leaf out beautifully in the spring.....go figure. Granted, this is a very mild climate compared to many, but when a shohin pot is frozen solid for a week, it's still frozen solid.

Grounding and mulching gives a good deal of outside winter protection.

Last year multiple spaces were used to winter over on/in the ground, pretty much equal exposure/protection as physically possible…but not exactly the same. It was noted some trees (same species similar size), especially on the periphery of the groups and others with less overall cover as the rest of the group, tended to be slower, weaker before recovering to full health. Simliar findings were seen at other locations. Wondering if that occurred at your location?

In any event, that’s where the issue lies. It’s not about death, which is certainly something to be concerned about. It’s the next level… all bonsai coming out of winter as robust and resilient as possible.

btw What all species are you growing nowadays? Still Japanese maples?

cheers
DSD sends

 

[rockm]

As a blanket statement is accurate….

Actually I lived just down the road in Dumfries for a number of years.



Here’s where the hang up always seems to appear.

The statement assumes a full freeze of a root ball is the only thing that will harm a tree. That there is a cut off where everything happens at once. That death is the cut off between healthy and unhealthy. Certainly not yet true. All roots on a tree are not equally hardy… and the ones that are least hardy are the ones that a tree needs most.

What is key here is keeping all the roots from being harmed, especially the feeder roots. (Tree death is over the top.) When this happens a tree prioritizes roort growth over growth in the trunk and branches (but not necessarily budding). This puts tree resiliency for upcoming work at risk.

cheers
DSD sends

You've read something that I didn't write. I didn't say a fully frozen root ball was the only thing that would harm a tree. I said intracellular water freezing is the cause. That can happen anywhere in the roots. Particularly if the cold spell last a long time. The longer the freeze, the more of the root mass is frozen, which increases the possibilities of roots being killed.

 

[MrFancyPlants]

I had only a couple maple and they unfortunately met with a not so watery demise with a summer vacation watering mishap. I have a few Canadian hemlock in larger pots, My JBP are either in the ground or in a flat as of yet. Elms, ginkgo.
I think the main trees that I am considering trying something different to for would be these three junipers on the lower bench which are in recovery after a rough year.

 

[BrianBay9]

When I used to have to overwinter in Wisconsin, my only losses were from critters chewing the bark - mice, voles, rabbits apparently loved my winter storage area. Had to change to my garage and even then had occasional chewing.

 

[Deep Sea Diver]

The OP is not in Washington state. They are in Washington DC/MD. I'm just south of them in No. Va. We have mild winters compared to Wisconsin, but harsh compared to Washington state. Lows can sometimes reach into sub-zero in bad winters. Normally nighttime lows are in the mid 20's in Jan. and Feb. They can go even lower for days on end. Duration of cold makes a big difference with overwintering, as well as only temperature. Exposure to prolonged deep freezes kills trees. Shohin and mame are usually the first to go.

A frozen pot is not a frozen pot. Depth of cold makes a huge difference. If that freeze is only into the mid-high 20's intracellular water generally doesn't freeze. Prolonged freezes below 25 F freezes intracellular water (water inside root tissue cells, as opposed to intercellular water between cells). That frozen intracellular water explodes living cells (like freezing a can of soda ruptures the aluminum as the content inside expand), damaging tissue or entire root systems.

Sorry If I misread. Winter damage isn’t that basic. There are many causes of root cell damage, not just intracellular liquid freezing.

Perhaps a diagram that outlines these causes would help. (Note death vs damage and these factors can occur simultaneously…)



This is where I’m coming from.

When I used to have to overwinter in Wisconsin, my only losses were from critters chewing the bark - mice, voles, rabbits apparently loved my winter storage area. Had to change to my garage and even then had occasional chewing.

…again ‘only losses’…

Cheers
DSD sends

 

[MrFancyPlants]

When I used to have to overwinter in Wisconsin, my only losses were from critters chewing the bark - mice, voles, rabbits apparently loved my winter storage area. Had to change to my garage and even then had occasional chewing.

I think this one is Siberian elm, had some vole damage about 15 years back. It was a stick in a pot “volunteer” early in my most recent period of interest in bonsai after college. It still is a stick in the pot in many ways, but I like the way the trunk healed from the vole damage.

 

[penumbra]

The OP is not in Washington state. They are in Washington DC/MD. I'm just south of them in No. Va. We have mild winters compared to Wisconsin, but harsh compared to Washington state. Lows can sometimes reach into sub-zero in bad winters. Normally nighttime lows are in the mid 20's in Jan. and Feb. They can go even lower for days on end. Duration of cold makes a big difference with overwintering, as well as only temperature. Exposure to prolonged deep freezes kills trees. Shohin and mame are usually the first to go.

A frozen pot is not a frozen pot. Depth of cold makes a huge difference. If that freeze is only into the mid-high 20's intracellular water generally doesn't freeze. Prolonged freezes below 25 F freezes intracellular water (water inside root tissue cells, as opposed to intercellular water between cells). That frozen intracellular water explodes living cells (like freezing a can of soda ruptures the aluminum as the content inside expand), damaging tissue or entire root systems.

I can always tell your posts by words and tone alone.

 

[rockm]

Sorry If I misread. Winter damage isn’t that basic. There are many causes of root cell damage, not just intracellular liquid freezing.

Perhaps a diagram that outlines these causes would help. (Note death vs damage and these factors can occur simultaneously…)

View attachment 459960

This is where I’m coming from.



…again ‘only losses’…

Cheers
DSD sends

Sorry If I misread. Winter damage isn’t that basic. There are many causes of root cell damage, not just intracellular liquid freezing.

Perhaps a diagram that outlines these causes would help. (Note death vs damage and these factors can occur simultaneously…)

View attachment 459960

This is where I’m coming from.



…again ‘only losses’…

Cheers
DSD sends

Well, OK. Looks like a "It wasn't the crash that killed the driver it was when his head hit the windshield..." kind of thing... From what I see in the chart, intracellular freezing IS ONE OF the "main" bad things listed in red. It is also at the top of that list--if that is a prioritized list...

 

[Deep Sea Diver]

Well, OK. Looks like a "It wasn't the crash that killed the driver it was when his head hit the windshield..." kind of thing... From what I see in the chart, intracellular freezing IS ONE OF the "main" bad things listed in red. It is also at the top of that list--if that is a prioritized list...

Well done!

Yep. Iit’s one of the key issues. Not sure from my reading the authors made any sort of prioritization. But, definitely, from any perspective intracellular freezing is certainly a fast road to perdition, if you get what I mean.

That diagram is also in the Overwintering resource just posted a couple days ago.

cheers
DSD sends

 

[Wires_Guy_wires]

I keep everything on the bench. Except for the plants that weren't on the bench in the first place.
Our winters are mild and rainy the past couple years so when pots are on the ground their holes get clogged up by mud and worm castings. With all those freeze thaw cycles we get, that's a recipe for pooling water (the pot core is last to thaw) so that's not something I'd choose for.

I own mostly conifers though.

 

[Tele]

Expecting minimum 23F / -5C. On my balcony (that can be closed with windows but not insulated) I will keep everything on benches including my Ficus.
Small attention to weather forecasts should be enough and I have just restarted this year so all my trees are mostly for testing. We´ll see what survives and can handle my limited options. This summer often well over 113F / 45C was more scary.
6 junipers, Serissa, madroño, ficus, 2 cryptomeria´s, 6 acasias, boxwood. Nothing died yet somehow. This balcony has been well over 122F / 50C. Now the winter test...