Overwintering advice

[BalconyBonsai]

Hi, I need some urgent advice on what I should do short term with overwintering my maples. We have yad a quite cold period lately with lies of around -5°C but and not a lot of wind. This weekend and the next week however really cold temps are forecast with the lowest being -19°C monday morning and then hovering around -6°C - -10°C the whole of next week.

My wintering setup has not gone according to plan, I built a structure out of styrofoam but that failed and I haven't managed to create a good replacement. At the moment they are placed on an appartment balcony facing south, standing on a thick styrofoam sheet. They are placed so that the balcony siding is sheltering them from the wind.

From what I can think of I have three options to try and ride this cold period out.
Either let them stay where they are and maybe try to improve the condition somehow. This doesn't seem like it would work since the temps will be very extreme.
Another option is to place them at my fathers house where he has a storage room connected to the house. At the moment, when the outside temps are -4°C, the temp in the room is 7°C but when it gets cold it can turn to freezing in there, at least it has done in the past.
The third option is an unheated shed in his back yard. This also seems it would still be too cold for the trees.

The trees in question are three acer palmatums and one trident maple. I know trident maples are supposed to be more sensitive to the cold so to be honest I don't know if has already died because of insufficient protection, but some sources seem to indicate that it is quite hardy so I won't give up on it.

So what would your suggestion be on what I should do? The risk I see with moving them into my fathers indoor storage room is if the temps don't get cold enough and the trees will start to think spring has come. But maybe that won't happen if they get no sunlight?

 

[Bnana]

They can handle a bit of frost. In the shed or storage room they should be fine. Outside might be a bit too much and they do not need sun now anyway.

 

[Cadillactaste]

Any way to run a portable heater in one of the buildings at your father's place? You will need a supplementing heat source. They say a tree watered well handles cold easier as well. At least for winds but when I see temps like that...I have a secondary heater for my controlled cold greenhouse. When you use one you need a thermometer with an alarm to know when/if if gets to warm you can shut it down. At night mine runs without a hiccup. It's day temps it usually can sometimes be shut down.

 

[Cadillactaste]

Did the conversion...to Fahrenheit. -2.2F still cold. Especially for trees in a pot. I would think it worth protecting. Ones I know would use a portable heater for those forecast temps who heat in their garage as well.

If you can't offer heat...I would still attempt to put them in a better shelter than the balcony.

Best of luck to you.

 

[sorce]

You're the guy with the pretty nice big maples ain't cha?

Anything less and I'd say just leave em, but.....

Are you SURE it's a Trident and not an Amur evilly disguised as a "Japanese Trident Maple".

Where does the seller keep his?

Local Ideas on Trident Maples?

Pretty sure I'm still in the do nothing camp.
At father's sounds like an accidental death, probably right before spring. That would suck. Too far to tend well.

Sorce

 

[Cadillactaste]

You're the guy with the pretty nice big maples ain't cha?

Anything less and I'd say just leave em, but.....

Are you SURE it's a Trident and not an Amur evilly disguised as a "Japanese Trident Maple".

Where does the seller keep his?

Local Ideas on Trident Maples?

Pretty sure I'm still in the do nothing camp.
At father's sounds like an accidental death, probably right before spring. That would suck. Too far to tend well.

Sorce

Sorce this cold sap won't last forever. How would it be accidental death? At least I took it as temporary housing while the cold spell moved out. Like when a storm is coming and ones sit things on the ground.

Maybe I read it wrong. But as of now they have no real protection on the balcony.

 

[sorce]

accidental death?

Forgetting to check on them.

I reckon you'd have to be there at least every day for a week to know what is going to be happening.

Things like a door left open so that room heats, mice, blah, blah...

Sorce

 

[Cadillactaste]

@sorce ... you don't winter in an outbuilding...do you?

I check my trees once a week. I mentioned the thermometer with an alarm. I'm sure one there is quite capable to hear it go off...if to hot or to cold and handle the heater if they used one.. without a heater...and it that cold.. there would be no reason to babysit daily.. I would water well once settled in. And check back in maybe under a week. Since its a new situation. But typically once a week watering is all a dormant tree needs if they are sheltered in.

Once it warms up without a thermometer with an alarm. It is dangerous. A warm winters day can wake them prematurely...without ventilation/opening a door.

 

[bwaynef]

I'd build protection at your apartment. Run a string of Christmas lights for heat (or larger bare bulb if Christmas lights are hard to come by at this time of the year). I wouldn't worry if it got down below freezing. You're just trying to knock the edge off it. (Padded/thick) Poster board, tape, and plastic, with those lights inside, ought to keep a few trees warm enough to survive. Add one of those cheap emergency solar blankets if you have one. This assumes you can build something large enough and well enough to house your trees.

I live where we don't see below 20ºF regularly, but occasionally down to as low as 6ºF, ...so take my recommendation for what it's worth.

 

[Cadillactaste]

@BalconyBonsai you were thinking only a temporary situation until the cold moved out?

Wintering in a sheltered location long term...not being there as sorce mentioned can be opening a can of worms..

I assumed you were only using it as a temporary situation until the frigid cold moved out..

So take what I said and all the issues of a warm winters day...and chew over it. I would do a temporary situation with no qualms.

 

[BalconyBonsai]

Did the conversion...to Fahrenheit. -2.2F still cold. Especially for trees in a pot. I would think it worth protecting. Ones I know would use a portable heater for those forecast temps who heat in their garage as well.

If you can't offer heat...I would still attempt to put them in a better shelter than the balcony.

Best of luck to you.

Hi, thanks for your replies! You are correct, this would only be a temporary solution to get through the cold spell. Then I would put them back on the balcony when temperatures are warmer. I think I will go with the option of putting them in the storage room that is connected to ly fathers house. My concern though is whether it would be too warm for them. And also me dad is not really interested in growing things so I can't rely on him watering them, since they will no longer be frozen. So I would need to go there regularly to water which can be difficult to fit in to the daily schedule.

We have had a lot of snow these past days. Would burying them in snow be an option? Snow should insulate quite well?

 

[Cadillactaste]

Snow is a very good insulator. But will the wind reach the branch tips? I protect my landscape from our arctic spells I use wooden stakes and burlap for wind breaks. I go around the entire tree/shrub leaving the top open. It keeps me from seeing dieback. Of course roots are in the ground. That is an option you could try. I've not used it for bonsai...so take it with a grain of salt.

 

[BalconyBonsai]

You're the guy with the pretty nice big maples ain't cha?

Anything less and I'd say just leave em, but.....

Are you SURE it's a Trident and not an Amur evilly disguised as a "Japanese Trident Maple".

Where does the seller keep his?

Local Ideas on Trident Maples?

Pretty sure I'm still in the do nothing camp.
At father's sounds like an accidental death, probably right before spring. That would suck. Too far to tend well.

Sorce

I don't know if I'm that guy. Two of them I'm quite attached to, the trident and one of the palmatums, so I would be sad if they were to not make it.

I think it is a trident but I'm far away from being an expert but I trust the seller. I bought it from bonsaischule wenddorf in germany.

I'm still hoping for the forecast to change but it does not seem likely.

 

[sorce]

germany

Ask @Walter Pall. I think I recall ALL the trees are just grounded, which could give you a ... foundation to start from. A good low one at that.

Sorce

 

[BalconyBonsai]

Snow is a very good insulator. But will the wind reach the branch tips? I protect my landscape from our arctic spells I use wooden stakes and burlap for wind breaks. I go around the entire tree/shrub leaving the top open. It keeps me from seeing dieback. Of course roots are in the ground. That is an option you could try. I've not used it for bonsai...so take it with a grain of salt.

Maybe a stupid idea but I was thinking of burying the whole trees, branches and all, in snow, not just the pots. But maybe that would be bad for the branches...

 

[Cadillactaste]

Not really. Depends on how careful you go about it. I've known ones who had trees buried in snow. Completely covered. But tossing it on...and the degree it lands on the branches...would be the deal/branch breaker. You have enough snow to cover everything?

 

[BalconyBonsai]

I don't have enough snow on the balcony but I could go down and collect in front of the building and bring up to the apartment. My neighbours will probably think I'm insane but we will be moving out within a couple of months so who cares

 

[AlainK]

the lowest being -19°C monday morning and then hovering around -6°C - -10°C the whole of next week.

That's very cold for potted trees. Acer palmatum can survive temperatures as low as -20°C at least when in the ground, but when potted, they risk to die if the temps stay at, say around -8°C (17 F ?) for more than a week. The Acer buergerianum are even more fragile.

Not very elegant, but covering them with some kind of anti-freeze mesh - don't know what it's called in English, you know the kind of white fabric that is easily available in garden centres here, would be a good option.

 

[BalconyBonsai]

I'd build protection at your apartment. Run a string of Christmas lights for heat (or larger bare bulb if Christmas lights are hard to come by at this time of the year). I wouldn't worry if it got down below freezing. You're just trying to knock the edge off it. (Padded/thick) Poster board, tape, and plastic, with those lights inside, ought to keep a few trees warm enough to survive. Add one of those cheap emergency solar blankets if you have one. This assumes you can build something large enough and well enough to house your trees.

I live where we don't see below 20ºF regularly, but occasionally down to as low as 6ºF, ...so take my recommendation for what it's worth.

Thanks for your suggestion! Something somewhat similar to this was my original plan for winter storage. Unfortunately I won't have the time to put anything complex together before this cold wave arrives.

 

[BalconyBonsai]

I think bringing them to my fathers storage room might be the safest option still... What temperature would trigger them to go out of their hibernation? And for how long would they need to stay at that temperature for it to happen? Or is it more related to the amount of sunshine they receive?