Need guidance - dormancy indoors (several species)

[Aphystic]

Hello, I’ve decided to buy a ts1000 and I’m planning to build a little 60x60cm (24x24”) box with mylar, pc fans and a humidifier alongside the grow light.

Prerequisite: Sweden, usda zone 7a (dark and cold October-mars), no access to garage or other area which is colder than 22c+ except for balcony but out there it could be +8c as well as -20c.

Trees I have: portulacaria afra (jade), carmona (Fukien tea), zelkova (Chinese elm) and sageretia (sweet plum). I also have a cutting which I’m doing a root over rock of a ficus Benjamina but the mother plant have survived without grow light for 10 years so I reckon it should survive as a “bonsai” as well. SEE PICTURES

I’ve read about doing their dormancy in a fridge, put it inside at 8c for 42 days or whatever it is and let it have its dormancy, not sure if that works but would be happy to get answers.


How should I treat my trees during a winter period?
Should I try to make some go dormant in a fridge? Is that crazy?
Keep them all under grow light the entire winter?

I put them outside when temperature allow me during the summer but otherwise they have to be indoors. Please give me all your tips how to treat all these different species that I have

Thank you !

 

[hemmy]

As stated on the other thread, growing outdoor trees indoors is challenging. BUT, your listed plants all have a tropical or subtropical lineage which makes it easier. I would treat the Chinese elm as subtropical and not try to force dormancy. Definitely don’t put it in the fridge. That is a specialized technique with tons of problems.

If they were mine and my first winter, I would not bother with the box. I’d get a light, humidifier, and small fan. The humidifier might not do much if they are in a large room, but you should have a humidifier in your heated space for your own health anyway. I wouldn’t put the fan too close. But here is the concern from your pics. The cold air will roll off those windows you might need to set them back a bit. The fan can help move that cold air away. Also, does the base of the window they are on get cold? If so, you may want to elevate them on a shelve.

Make sure your LED has a dimmer. I still prefer T5 fluorescents for living spaces. But there are several threads on here with people using LED on shelves indoors. You might consider the Mylar sheet to hang off the side of your LED to minimize light pollution into your living space.

I do not believe evaporative trays of water add much himudity. But I would look for trays or bins to aid in watering and moving them about. Indoor watering is a real pain in the butt.

I’d try to limp then along through your first winter and then improve on your setup as you learn what they need.

Good luck!

 

[Aphystic]

As stated on the other thread, growing outdoor trees indoors is challenging. BUT, your listed plants all have a tropical or subtropical lineage which makes it easier. I would treat the Chinese elm as subtropical and not try to force dormancy. Definitely don’t put it in the fridge. That is a specialized technique with tons of problems.

If they were mine and my first winter, I would not bother with the box. I’d get a light, humidifier, and small fan. The humidifier might not do much if they are in a large room, but you should have a humidifier in your heated space for your own health anyway. I wouldn’t put the fan too close. But here is the concern from your pics. The cold air will roll off those windows you might need to set them back a bit. The fan can help move that cold air away. Also, does the base of the window they are on get cold? If so, you may want to elevate them on a shelve.

Make sure your LED has a dimmer. I still prefer T5 fluorescents for living spaces. But there are several threads on here with people using LED on shelves indoors. You might consider the Mylar sheet to hang off the side of your LED to minimize light pollution into your living space.

I do not believe evaporative trays of water add much himudity. But I would look for trays or bins to aid in watering and moving them about. Indoor watering is a real pain in the butt.

I’d try to limp then along through your first winter and then improve on your setup as you learn what they need.

Good luck!

So keep all of my trees under the grow light all winter? Like evergreens?

I’ll put them on the floor in a plastic tray during the winter so won’t be placed on the sills.

Thank you

 

[pandacular]

Your original plan, specifically the enclosed box, sounds pretty cool and could really help accelerate growth. I could also just as easily see it killing trees if you do something wrong. tho I say both these things as someone who knows little about indoor tree growing, just seen some of the results of others on here. I think it's worth exploring, but unless your passion lies in building something like that (which it's awesome if it does!) I would keep it simpler to start.

 

[Cadillactaste]

I always think of Sergio's attempt at dormancy prolonged...in a fridge. I don't recommend that route ...

SHOHIN CASCADE Kiyohime

Starting a new thread on this shohin maple. Last year in late winter, I placed this tree in a refrigerator in an effort to delay bud brake. I kept the tree inside it for nearly three weeks. Unbeknownst to me, the dry air inside the fridge desiccated the fine twigs and branches despite being kept...

www.bonsainut.com

 

[rockm]

None of the trees listed, with the exception of the elm, require dormancy.

 

[Aphystic]

None of the trees listed, with the exception of the elm, require dormancy.

What I’ve read is that trees that don’t undergo dormancy for a time period of several years 5+, grow weak and eventually die but maybe it’s all an urban legend?

I just want my trees to be happy.
It’s funny you mentioned the Chinese elm because it’s one of the few ones I’ve read about not requiring dormancy and instead turn into an evergreen

 

[Cadillactaste]

What I’ve read is that trees that don’t undergo dormancy for a time period of several years 5+, grow weak and eventually die but maybe it’s all an urban legend?

I just want my trees to be happy.
It’s funny you mentioned the Chinese elm because it’s one of the few ones I’ve read about not requiring dormancy and instead turn into an evergreen

I've never heard anyone, not permitting Zelkova a dormancy period... we are now breaking down species into cultivar needs. Understand that.

A tree that needs dormancy...will weaken and die if not given it over a period of time.

 

[Shibui]

What I’ve read is that trees that don’t undergo dormancy for a time period of several years 5+, grow weak and eventually die but maybe it’s all an urban legend?

This is for trees from temperate climates where they have adapted to cold winters. The trees you have listed are all tropical or sub-tropical specie which never naturally face cold winters so they do not need winter dormancy. These species grow whenever water and temps are conducive. No dormancy needed - ever.
The exception has already been mentioned but there is discrepancy with the name. Zelkova/Chinese elm are NOT the same species. Zelkova is usually Japanese grey bark elm. Chinese elm is Ulmus parvifolia but I read that importers in Europe get around import bans by mislabelling one species as another. Chinese elm does not need winter dormancy but I suspect that zelkova may need some dormant period.

 

[Cadillactaste]

This is for trees from temperate climates where they have adapted to cold winters. The trees you have listed are all tropical or sub-tropical specie which never naturally face cold winters so they do not need winter dormancy. These species grow whenever water and temps are conducive. No dormancy needed - ever.
The exception has already been mentioned but there is discrepancy with the name. Zelkova/Chinese elm are NOT the same species. Zelkova is usually Japanese grey bark elm. Chinese elm is Ulmus parvifolia but I read that importers in Europe get around import bans by mislabelling one species as another. Chinese elm does not need winter dormancy but I suspect that zelkova may need some dormant period.

Thanks for sharing... I wasn't going to contradict his labeling the elm. Didn't feel like opening a can of worms. But...point on.

But also...I was unaware of the mislabeled to get around bans. So thanks...I love when I can tuck new knowledge in the vault.

 

[hemmy]

So keep all of my trees under the grow light all winter? Like evergreens?

@Shibui, just typed everything I was going to say.

I’ll put them on the floor in a plastic tray during the winter so won’t be placed on the sills.

My point about the window is just to be aware of the possible temperature challenges. I grow things next to a window in the winter with no issue. But you are in a colder climate. I’d favor the window and light over a floor. But you’ll have to play with your own setup for the best results.

Also, spray them an insecticidal soap before bringing them inside. Even if you think they don’t have any insects. Once they come inside there are no beneficial insect predators and just a few pests can multiply quickly.

 

[rockm]

What I’ve read is that trees that don’t undergo dormancy for a time period of several years 5+, grow weak and eventually die but maybe it’s all an urban legend?

I just want my trees to be happy.
It’s funny you mentioned the Chinese elm because it’s one of the few ones I’ve read about not requiring dormancy and instead turn into an evergreen

Tropical and subtropical species don't require much, if any, dormancy, certainly not enough to warrant such an elaborate set up or use of a cold, dry refrigerator (which, BTW doesn't induce dormancy as much as it shocks trees into inactivity). They come from areas that don't experience much, if any, winter.

Chinese elm will burn out and die over a few years inside with no dormancy. Ask to see one that's been kept indoors for more than five years...You'll get one or two photos out of the literal thousands that are sold every year...Zelkova is NOT Chinese elm, as has been pointed out. Chinese elm is often sold as Zelkova when it is imported into the U.S., because of stricter importing restrictions on Chinese Elm (which has harbored vastly destructive Asian Longhorn beetles)

Portulacaria is native to South Africa. The species does slow down in the winter, but it doesn't require below freezing temps to overwinter.

Fukien tea (Carmona) is native to subtropical regions of Japan, Southeast Asia and Australia. It also doesn't require a cold dormancy.

Sweet plum is native to S.E. Asia and Africa. It can withstand occasional light freezing as a landscape plant, but does not require deep winter dormancy.

 

[Aphystic]

This is for trees from temperate climates where they have adapted to cold winters. The trees you have listed are all tropical or sub-tropical specie which never naturally face cold winters so they do not need winter dormancy. These species grow whenever water and temps are conducive. No dormancy needed - ever.
The exception has already been mentioned but there is discrepancy with the name. Zelkova/Chinese elm are NOT the same species. Zelkova is usually Japanese grey bark elm. Chinese elm is Ulmus parvifolia but I read that importers in Europe get around import bans by mislabelling one species as another. Chinese elm does not need winter dormancy but I suspect that zelkova may need some dormant period.

Said Zelkova on the plant passport, here’s a picture

 

[Shibui]

Said Zelkova on the plant passport, here’s a picture

Looks like Chinese elm - Ulmus parvifolia so one of those intentional European mislabelled trees to beat import bans.

Bonsai growers in tropical parts of Australia find these do well because they do not need dormancy. You should find it will keep leaves all year round unless temps get close to freezing. Repotting in temperature areas where they do drop leaves is traditionally spring like other deciduous but in warmer places when they never go dormant growers have found they can be repotted and root pruned any time of year.
No need to worry about dormancy for any of the trees on your list.
@rockm points about surviving longer term indoors is valid. It can be done but usually only successful longer term with strict conditions - light, humidity, air movement, etc, etc. We see many Chinese elms posted here that are dying because they do not like normal indoor conditions. Disappointed buyers mislead by the optimistic(?) labelling

 

[Aphystic]

Looks like Chinese elm - Ulmus parvifolia so one of those intentional European mislabelled trees to beat import bans.

Bonsai growers in tropical parts of Australia find these do well because they do not need dormancy. You should find it will keep leaves all year round unless temps get close to freezing. Repotting in temperature areas where they do drop leaves is traditionally spring like other deciduous but in warmer places when they never go dormant growers have found they can be repotted and root pruned any time of year.
No need to worry about dormancy for any of the trees on your list.
@rockm points about surviving longer term indoors is valid. It can be done but usually only successful longer term with strict conditions - light, humidity, air movement, etc, etc. We see many Chinese elms posted here that are dying because they do not like normal indoor conditions. Disappointed buyers mislead by the optimistic(?) labelling

Is there something I can do to make my Chinese elm survive and thrive indoors during the winter? My plan is to keep it outside until night temperature hits around 12c, maybe it can be kept outside for longer (lower temp?).

 

[rockm]

Said Zelkova on the plant passport, here’s a picture

Not zelkova, sorry. Definitely a Chinese elm. Zelkova has larger, more pointed leaves and longer internodes.

 

[rockm]

Is there something I can do to make my Chinese elm survive and thrive indoors during the winter? My plan is to keep it outside until night temperature hits around 12c, maybe it can be kept outside for longer (lower temp?).

The best thing you can do for your Chinese elm is not keep it indoors. If you're in the equivalent of USDA zone 7a the tree will have little, if any problem overwintering outside under a layer of mulch in a garden bed. I've kept them here in Va. (USDA Zone 7a) for decades like that.

If you do choose to keep it indoors, to make it "happy" will require high output lighting, and increased humidity-- like in a dedicated room that is kept at at least 65 percent humidity, preferably more--which is problematic as that also grows mold. To have it limp along all winter, drop leaves and lose twigging and branching, do nothing but plunk it on a windowsill.

Sorry to be so negative, but mostly those are the bottom line for most indoor Chinese elms...

 

[Aphystic]

The best thing you can do for your Chinese elm is not keep it indoors. If you're in the equivalent of USDA zone 7a the tree will have little, if any problem overwintering outside under a layer of mulch in a garden bed. I've kept them here in Va. (USDA Zone 7a) for decades like that.

If you do choose to keep it indoors, to make it "happy" will require high output lighting, and increased humidity-- like in a dedicated room that is kept at at least 65 percent humidity, preferably more--which is problematic as that also grows mold. To have it limp along all winter, drop leaves and lose twigging and branching, do nothing but plunk it on a windowsill.

Sorry to be so negative, but mostly those are the bottom line for most indoor Chinese elms...

I don’t mind putting it outdoors but I live in an apartment and only have access to a balcony. Can I do something else to have it survive outdoors? See attached file for average temperature each month. Left hand side is day temp and right hand side is night temperature, it’s in Swedish but almost same as English anyway. Can I keep it outside in a bigger pot and wrap it in bubble wrap or something? It’s the roots that need protecting and not the branches and trunk?

I just need to know how to keep it alive. I have a full size Japanese maple (not bonsai) on my balcony which survives the winter without any hassle.

 

[rockm]

I don’t mind putting it outdoors but I live in an apartment and only have access to a balcony. Can I do something else to have it survive outdoors? See attached file for average temperature each month. Left hand side is day temp and right hand side is night temperature, it’s in Swedish but almost same as English anyway. Can I keep it outside in a bigger pot and wrap it in bubble wrap or something? It’s the roots that need protecting and not the branches and trunk?

I just need to know how to keep it alive. I have a full size Japanese maple (not bonsai) on my balcony which survives the winter without any hassle.

If you have a Japanese maple that is successful out on the balcony, you can overwinter this elm there. Come late November (and the tree should be outside from now until then, yes, even with frosts and freezes that don't go below 20 F or so--these help the plant understand it's time to go dormant--as well as the shortening days through fall--both cold intervals and shortening days are critical for overwintering deciduous temperate zone trees and are among the things people don't "get" about dormancy. Those signals should tell the plant to drop leaves (although Chinese elms can be persistent about not dropping leaves in winter sometimes. Not a big deal. The leaves will eventually drop and be replaced come spring time).

In November, I'd get a pot three time larger than the pot the tree is in now with substantial drain holes in the bottom, as well as a large heavy object that the bonsai pot can be stacked on inside the larger pot. Place the small pot on the stand inside the larger pot. The level of the bonsai pot should still remain two or three inches below the rim of the larger pot. When the small tree is in place on its small stand inside the large pot, water the tree well. Get a bag of shredded pine bark mulch (meant for landscaping) and backfill the larger pot all the way around the bonsai and up over the top of the bonsai pot at least two inches. Water well again to insure the mulch is moist and that it drains.

Leave the plant alone for the most part for the next few months. Check to make sure the bonsai pot and mulch remain moist--not soggy throughout the winter. If you get snow, even better, pile it on top of the bonsai pot and around the larger pot. Snow makes an excellent shield against colder weather. Make sure the pots don't remain soaked in winter rains, although the rain should drain through the mulch and elevated soil without much problem if the large pot has adequate drainage.

 

[Aphystic]

If you have a Japanese maple that is successful out on the balcony, you can overwinter this elm there. Come late November (and the tree should be outside from now until then, yes, even with frosts and freezes that don't go below 20 F or so--these help the plant understand it's time to go dormant--as well as the shortening days through fall--both cold intervals and shortening days are critical for overwintering deciduous temperate zone trees and are among the things people don't "get" about dormancy. Those signals should tell the plant to drop leaves (although Chinese elms can be persistent about not dropping leaves in winter sometimes. Not a big deal. The leaves will eventually drop and be replaced come spring time).

In November, I'd get a pot three time larger than the pot the tree is in now with substantial drain holes in the bottom, as well as a large heavy object that the bonsai pot can be stacked on inside the larger pot. Place the small pot on the stand inside the larger pot. The level of the bonsai pot should still remain two or three inches below the rim of the larger pot. When the small tree is in place on its small stand inside the large pot, water the tree well. Get a bag of shredded pine bark mulch (meant for landscaping) and backfill the larger pot all the way around the bonsai and up over the top of the bonsai pot at least two inches. Water well again to insure the mulch is moist and that it drains.

Leave the plant alone for the most part for the next few months. Check to make sure the bonsai pot and mulch remain moist--not soggy throughout the winter. If you get snow, even better, pile it on top of the bonsai pot and around the larger pot. Snow makes an excellent shield against colder weather. Make sure the pots don't remain soaked in winter rains, although the rain should drain through the mulch and elevated soil without much problem if the large pot has adequate drainage.

I shall try this, for my other trees

Sageretia sweet plum
Carmona fukien tea
P afra dwarf jade

Should I keep those inside and under the grow light while the Chinese elm is having its dormancy ?