Overwintering on balcony

[BonPiotr]

Hi,
i'm thinking about possible ways to protect my trees in winter time, but i can't find any info that are appriopriate for my situation. I live on 3rd floor and my trees are placed on balcony, my USDA zone is 6b/7a (depends on a map, i live in Poland). I have a wall there that can block wind completely from one side. As of species currently i have:
- European Beech in starting phase of kabudachi style development, they are not fused together yet,
- Chinese Elm of unknown origin, but i think it can be from southern China, so i don't know how hardy it is. Also it's cheap commercial bonsai and i had to repot it mid august, because of big root rot and falling leaves (it was in very bad dense soil and came to me soggy wet),
- Juniperus Sabina Tamariscifoglia, still in nursery pot, but styled this year, this one seems healthy and hardy.

My current plan is:
- 5 cm thick styrofoam for bottom insulation,
- cold frame on top of styrofoam,
- thick layer of mulch to cover pots to the rim,
- optional styrofoam insulation and blanket in case of temps below 20F/-6C,
- constant temperature monitoring with wi-fi thermometer and push notifications on certain thresholds.

Alternative plan is to put everything in totally unheated part of house at my parents place, but I'm concerned if they would know how to properly water my trees and don't know what temperature will be inside (probably above 32F/0C, but i don't know if it will be cool enough). They also have unheated greenhouse. Which plan sounds better? When should I relocate trees to protected space? Is there any bulletproof plan for watering trees inside that unheated space, so i can give my parents simple instructions?

 

[Paradox]

You want below 40 degrees F consistently and the house will be higher than that.
Bringing them into the house will cause them to come out dormancy too early.

You are going to have to try the method you are describing with the box.
The main thing is to keep them out of the wind.
Not sure how it will work but it is the only alternative you have it seems unless you know someone with property or if there is a bonsai place that will overwinter trees for a fee.
The house is absolutely not going to work.

 

[Mikecheck123]

Hi,
i'm thinking about possible ways to protect my trees in winter time, but i can't find any info that are appriopriate for my situation. I live on 3rd floor and my trees are placed on balcony, my USDA zone is 6b/7a (depends on a map, i live in Poland). I have a wall there that can block wind completely from one side. As of species currently i have:
- European Beech in starting phase of kabudachi style development, they are not fused together yet,
- Chinese Elm of unknown origin, but i think it can be from southern China, so i don't know how hardy it is. Also it's cheap commercial bonsai and i had to repot it mid august, because of big root rot and falling leaves (it was in very bad dense soil and came to me soggy wet),
- Juniperus Sabina Tamariscifoglia, still in nursery pot, but styled this year, this one seems healthy and hardy.

My current plan is:
- 5 cm thick styrofoam for bottom insulation,
- cold frame on top of styrofoam,
- thick layer of mulch to cover pots to the rim,
- optional styrofoam insulation and blanket in case of temps below 20F/-6C,
- constant temperature monitoring with wi-fi thermometer and push notifications on certain thresholds.

Alternative plan is to put everything in totally unheated part of house at my parents place, but I'm concerned if they would know how to properly water my trees and don't know what temperature will be inside (probably above 32F/0C, but i don't know if it will be cool enough). They also have unheated greenhouse. Which plan sounds better? When should I relocate trees to protected space? Is there any bulletproof plan for watering trees inside that unheated space, so i can give my parents simple instructions?

The Chinese elm can certainly live inside all winter no problem, if that makes things easier.

 

[BonPiotr]

You want below 40 degrees F consistently and the house will be higher than that.
Bringing them into the house will cause them to come out dormancy too early.

You are going to have to try the method you are describing with the box.
The main thing is to keep them out of the wind.
Not sure how it will work but it is the only alternative you have it seems unless you know someone with property or if there is a bonsai place that will overwinter trees for a fee.
The house is absolutely not going to work.

Thanks Paradox, yeah it is highly possible it will be higher than 40F inside, even if it is not heated, separate and unfinished part of house. Sometimes i see people using something called agrotextile on trees planted in the ground. Maybe it's safer than my idea with cold frame? Ofcourse i would have to protect roots also.

Here's a picture of that product in use:


Sadly I don't know anyone with nice heated greenhouse and bonsai in my country is very niche hobby

 

[BobbyLane]

Theres a couple guys in Eastern europe on here who grow on balconies here, do a search with balcony and bonsai. I leave mine out all year on my balcony.
your trees will be fine up against the wall. bear in mind on a balcony in winter trees in close proximity to the building will benefit from residual heat from the building, it will be much colder further away from the building.
For example my pots rarely frost over in winter, but in a garden they usually would.

 

[BonPiotr]

Your trees will be fine up against the wall. Bear in mind on a balcony in winter trees in close proximity to the building will benefit from residual heat from the building, it will be much colder further away from the building.

Yeah, i was thinking about placing that cold frame in a corner so it receives heat from two walls. On the other side of one wall, inside a house, there's a heater, so outside wall should be even warmer

I leave mine out all year on my balcony.

But you are living in different climate. I have watched Peter-chan videos about wintering and winters in England seems much, much milder, than here in Poland.

There's one more thing, for sure i will have to water trees from time to time to prevent drying out. I still don't know how to do it without breaking whole "bark around pots" setup and making big mess. I was also thinking about using hay or straw, because it's still good insulator, less prone to fungi and easier to move when watering trees. One bonsaist from Poland uses it, when wintering trees simply on the ground level.

I think i have also good candidate for a cold frame :


Edit/PS: I'm not that much afraid of frosts (I can easily protect everything from it), what i'm afraid of is few days of chilly temperatures below 20F/-6, which probably can kill my elm and worsen health of 2 other trees.

 

[Paradox]

Yeah, i was thinking about placing that cold frame in a corner so it receives heat from two walls. On the other side of one wall, inside a house, there's a heater, so outside wall should be even warmer

But you are living in different climate. I have watched Peter-chan videos about wintering and winters in England seems much, much milder, than here in Poland.

There's one more thing, for sure i will have to water trees from time to time to prevent drying out. I still don't know how to do it without breaking whole "bark around pots" setup and making big mess. I was also thinking about using hay or straw, because it's still good insulator, less prone to fungi and easier to move when watering trees. One bonsaist from Poland uses it, when wintering trees simply on the ground level.

I think i have also good candidate for a cold frame :
View attachment 455732

Edit/PS: I'm not that much afraid of frosts (I can easily protect everything from it), what i'm afraid of is few days of chilly temperatures below 20F/-6, which probably can kill my elm and worsen health of 2 other trees.

Just be careful with that as it can heat up in the sun

 

[rockm]

You are overestimating and overthinking what you need to do. All the plants you've listed are quite capable of handling a winter in your area. The species you're using have been traditional bonsai subjects for quite some time and have survived without greenhouses and heat. BTW, the object of winter storage IS NOT TO KEEP PLANTS WARM. It is to keep them as cold as possible for as long as possible. "Warm" for overwintering is below 35 F down to 20 F. The cold frame will keep things far too warm and will be unstable--smaller enclosed shelters like that can vary wildly in temperature day to night since they have no mass to keep their temps stabilized.

If I were you, I'd simply put the plants up next to the wall of the building and bury their roots up to the trunk with mulch. Mulch will lag air temps considerably--the deeper and bigger the pile, the more mass the pile has and the "warmer" it will stay inside the pile (Where the roots are). Keep the trees out of the wind--a windbreak of some kind will help--plywood board, cover them with burlap, etc. You won't need that agrotextile (Which is mostly silly). Burlap is better, since it exchanges air better.

 

[Wood]

I had to deal with this last winter, so hopefully my experience will be helpful. The important bits of my situation:

• Zone 7a
• 4th floor balcony, overhung with no wall
• West-facing exposure

For my setup, I got a very large storage bin (approx 5'/1.7m long, 3'/1m wide, 2'/.6m deep) and drilled a handful of small holes so water wouldn't pool in it. Then, 2"/5cm of mulch in the bottom, put all the pots inside, then added mulch up to the rims of the pots. The storage bin sat immediately next to the sliding glass door onto my balcony. No top cover at all through the entire winter. The sides of the bin provided

I overwintered a dawn redwood, coast redwood sapling, giant sequoia sapling, a shohin azalea that had just transferred from South Carolina (zone 8?), three shohin junipers including one very weak one, a stewartia sapling, and a handful of trident maple cuttings and kishu juniper cuttings. Everything in the box survived the winter easily

I also had an European beech, a Jaqueline Hillier elm, and a yew just on the balcony with no insulation. I know that the beech and the JH elm can take much colder temperatures without issue, so I just made sure they had a little wind protection

I think your plan overall is pretty good, but I don't think you really need the cold frame. The sides of it will definitely help with wind protection, but if it gets into the sun, it'll definitely heat up way too fast. Maybe leave it open by default and only close it if temperatures will get below 20F/-6C. I don't think the extra blanket or foam insulation would be necessary

 

[BonPiotr]

Thanks @Wood, thanks @rockm Your input is great! So! I will buy some big wooden storage bin/pot, fill it with mulch and after spring comes grow veggies/herbs there. Two birds with one stone! That cold frame that I have previously chosen, can be opened completely, but probably you're right and it will get too warm during sunny days or milder winter.

 

[rockm]

Thanks @Wood, thanks @rockm Your input is great! So! I will buy some big wooden storage bin/pot, fill it with mulch and after spring comes grow veggies/herbs there. Two birds with one stone! That cold frame that I have previously chosen, can be opened completely, but probably you're right and it will get too warm during sunny days or milder winter.

I wouldn't put them in a bin. That will make watering the trees a bit complicated. The bin, if you use one, should drain and not hold water. The trees will require watering every so often if they aren't exposed to rain/snow. BTW, if it does snow, pile that on top of the mulch and you won't have to worry about watering as much.

 

[Wood]

I wouldn't put them in a bin. That will make watering the trees a bit complicated. The bin, if you use one, should drain and not hold water. The trees will require watering every so often if they aren't exposed to rain/snow. BTW, if it does snow, pile that on top of the mulch and you won't have to worry about watering as much.

For what it's worth, I did add drainage holes and watered occasionally throughout the winter

Here's a picture of my storage bin after it had snowed. Couldn't find a clearer picture of it unfortunately

 

[BonPiotr]

I wouldn't put them in a bin. That will make watering the trees a bit complicated. The bin, if you use one, should drain and not hold water. The trees will require watering every so often if they aren't exposed to rain/snow. BTW, if it does snow, pile that on top of the mulch and you won't have to worry about watering as much.

My friend has a big wooden pot, so i will borrow it for winter (probably 90x50x50 cm, should be enough) It has drainage holes on the bottom, so no problem with watering and i will have to do it, because my balcony has roof and i rarely see any rain or snow on the floor closer to the wall.

 

[ibakey]

For what it's worth, I did add drainage holes and watered occasionally throughout the winter

Here's a picture of my storage bin after it had snowed. Couldn't find a clearer picture of it unfortunately

Whoa, that image of snow coming onto your balcony makes light of the cold that we have in France. Haha. Good luck with the growing on the balcony too.

 

[Wood]

It was one of two, maybe three, snow storms we had last winter. The snow usually melts completely within a few days of it falling