Your thoughts on winter "maintenance" pruning as a space-saving solution?

[August]

First post!

I spent the last year developing a fascination with this art as well as collecting a nigh unmanageable assortment of starter material (mostly free, plants that would have otherwise been thrown away at my work). Naturally, it's a blessing and a curse, to have so much material to learn with and only so much space. This is all to say that, the south facing windows of my apartment are burdened with tropicals. They have room to breathe, and equal access to light and ventilation, but little room to grow. It stays pretty warm despite winter being weeks away (top floor, old school radiator heating) and most of them are happy to keep growing despite the lack of space. At least twice now, I have done "maintenance pruning" on several to either keep them manageable (not growing into a fixture or simply outgrowing the room they have on the shelf) or in some cases to keep whatever little structure they have from absolutely dissolving (a couple Cestrum nocturnum, dumb experiments that I became attached to, which just want to put out leggy, thick branches that go straight up).

From what I understand (relatively little), winter is a time for rest and dormancy, and a time for our trees to build reserves so they can have a good growing season during the better half of the year. I suppose that what I'm worrying over is whether or not these frequent cutbacks (usually followed by tons of back-budding with the cestrum, bougainvillea, lantana, and ficus) is depleting their reserves rather than building them, and that in the spring I will be moving out a menagerie of very very tired plants. They're otherwise healthy, but sometimes it's the little things that keep you up at night.

What are your thoughts?

 

[Wires_Guy_wires]

My thoughts are that tropicals usually don't build reserves in winter, but spend them instead. They, as many other plants, build reserves in wet seasons. Winter is considered the dry season.
If they even build up reserves at all, because some tropicals just don't.
As long as they're growing, it means they have plenty of resources. So pruning shouldn't be an issue. If a plant has completely stalled it'd be a different story.

 

[Leo in N E Illinois]

"Tropical" trees that keep on growing indoors will naturally need pruning if they outgrow the space one allows for them. I put tropical in quotes because few trees grown indoors are true tropical trees, but rather are various trees that are able to grow opportunistically when brought indoors.

Just accept that you need to prune them if they out grow the best space you allow.

But you might get better long term results if for the zone 7 & 8 hardy you found a way to winter them at cooler temperatures that would keep them dormant, without getting so cold you kill them.

For example I'm in zone 5b or 6a. (depends on what map you check). Pomegranate is hardy to maybe +25F or -4 C. This is not hardy in my area. I used to treat my pomegranate as a "tropical" putting it with my orchids for the winter. It would grow year round. Growth was weak over winter, usually got pruned away in spring.

Then I found a way to keep the tree in a cool dormancy. I kept it 32Fbto 40 F all winter. ( 0 C to + 4 C) . It then would stay dormant most of the winter. It would break dormancy in March, it would get moved to windows, then outside. After a cold dormancy spring and summer growth would be MUCH more vigorous, sturdy, and better for development..

With zone 7&8 subtropical trees a cold dormancy will give much better growth overall. Pomegranate, Centrum and similar species

Bougainvillea is from a wet-dry tropics zone, It is not really a cold tolerant plants, but dry seasons tend to be cooler at night ( cloudless skies results in lower night temps) but always above freezing. Small bougies, bonsai size, don't tolerate drought well. Bougainvillea with trunks the same diameter or larger than a grown man's leg, can go 3 months without any water. But small bougies need water all year round.

You need to learn about each species of tree you have, some will have so much better with a cool dormancy, below 45F but above freezing. Some really prefer warmer winter temperatures.

You can make a list and ask in this thread if you want.

 

[ShadyStump]

Finding space indoors for tropicals is a common problem many of us face. Most trees will be fine, but @Leo in N E Illinois has outlined the potential complications.

To illustrate, though it's not exactly what most people think of, I have an Italian sweet cherry pepper that's on it's 4th winter, and really looking haggard. The regular garden variety pepper plants you find here are all the exact same species, capsicum annum, and are SUBtropical bushes. They usually only live 2 to 3 years if kept going indoors. I managed to give it a dormancy in it's 2nd winter, and it did wonderfully the next season. This year it's on its last leg, but I'm convinced I could get at least another year or two out of it if I had somewhere to safely give it a month or two dormancy again.

Something to consider is light requirements. For most trees, light plays as big a factor in triggering dormancy, or at least a slow growing rest period, as temperature. If you can find a darker cooler corner for some of your trees, that might be enough to slow them down enough to get some rest. You'll have to research each species' needs.

Also, am I SERIOUSLY the only Coloradan here NOT in Denver?!?!
I'm running out of Denverite cracks to make.

 

[ShadyStump]

Oh, and welcome to the site.
Glad to have you.
Good folks, all.
If you run into the governor, tell him to send some snowplows to THE REST OF THE STATE this winter. Thanks!

Ok, love ya, ba-bye!

 

[August]

"Tropical" trees that keep on growing indoors will naturally need pruning if they outgrow the space one allows for them. I put tropical in quotes because few trees grown indoors are true tropical trees, but rather are various trees that are able to grow opportunistically when brought indoors.

Just accept that you need to prune them if they out grow the best space you allow.

But you might get better long term results if for the zone 7 & 8 hardy you found a way to winter them at cooler temperatures that would keep them dormant, without getting so cold you kill them.

For example I'm in zone 5b or 6a. (depends on what map you check). Pomegranate is hardy to maybe +25F or -4 C. This is not hardy in my area. I used to treat my pomegranate as a "tropical" putting it with my orchids for the winter. It would grow year round. Growth was weak over winter, usually got pruned away in spring.

Then I found a way to keep the tree in a cool dormancy. I kept it 32Fbto 40 F all winter. ( 0 C to + 4 C) . It then would stay dormant most of the winter. It would break dormancy in March, it would get moved to windows, then outside. After a cold dormancy spring and summer growth would be MUCH more vigorous, sturdy, and better for development..

With zone 7&8 subtropical trees a cold dormancy will give much better growth overall. Pomegranate, Centrum and similar species

Bougainvillea is from a wet-dry tropics zone, It is not really a cold tolerant plants, but dry seasons tend to be cooler at night ( cloudless skies results in lower night temps) but always above freezing. Small bougies, bonsai size, don't tolerate drought well. Bougainvillea with trunks the same diameter or larger than a grown man's leg, can go 3 months without any water. But small bougies need water all year round.

You need to learn about each species of tree you have, some will have so much better with a cool dormancy, below 45F but above freezing. Some really prefer warmer winter temperatures.

You can make a list and ask in this thread if you want.

What a wealth of information! I do know my various trees well and their hardiness zones ( I've spent all spring and summer fretting over winterizing) and everything I have inside is zone 9 or above (there is a star jasmine, 8-10, but doing great so far inside). One of my cestrum has been stalling for a while but I attributed that to my mix + underwatering issues (I'm never using crappy turface based prepackaged bonsai mix again, haha). A full list would be quite a read. But the main ones I'm concerned for were: Cestrum nocturnum, lantana, bougie, citrus (orange), schefflera, and adenium. Thank you again!

 

[August]

Oh, and welcome to the site.
Glad to have you.
Good folks, all.
If you run into the governor, tell him to send some snowplows to THE REST OF THE STATE this winter. Thanks!

Ok, love ya, ba-bye!

I've already noticed so many Coloradan's on this site! Hello!

I also have some peppers inside, struggling, but I was prepared for that. Mostly have them because I 'inhereted' them, in a tragic fashion, and they're sentimental.

Crack all you want about Denverites, we gain a whole extra zone depending on who you ask heat bubble and all. Either way, I'm young, and city life suits me for now If you run into the spirit of the Rocky Mountains, tell him to send some precipitation to the rest of the dang state!

 

[HorseloverFat]

"Tropical" trees that keep on growing indoors will naturally need pruning if they outgrow the space one allows for them. I put tropical in quotes because few trees grown indoors are true tropical trees, but rather are various trees that are able to grow opportunistically when brought indoors.

Just accept that you need to prune them if they out grow the best space you allow.

But you might get better long term results if for the zone 7 & 8 hardy you found a way to winter them at cooler temperatures that would keep them dormant, without getting so cold you kill them.

For example I'm in zone 5b or 6a. (depends on what map you check). Pomegranate is hardy to maybe +25F or -4 C. This is not hardy in my area. I used to treat my pomegranate as a "tropical" putting it with my orchids for the winter. It would grow year round. Growth was weak over winter, usually got pruned away in spring.

Then I found a way to keep the tree in a cool dormancy. I kept it 32Fbto 40 F all winter. ( 0 C to + 4 C) . It then would stay dormant most of the winter. It would break dormancy in March, it would get moved to windows, then outside. After a cold dormancy spring and summer growth would be MUCH more vigorous, sturdy, and better for development..

With zone 7&8 subtropical trees a cold dormancy will give much better growth overall. Pomegranate, Centrum and similar species

Bougainvillea is from a wet-dry tropics zone, It is not really a cold tolerant plants, but dry seasons tend to be cooler at night ( cloudless skies results in lower night temps) but always above freezing. Small bougies, bonsai size, don't tolerate drought well. Bougainvillea with trunks the same diameter or larger than a grown man's leg, can go 3 months without any water. But small bougies need water all year round.

You need to learn about each species of tree you have, some will have so much better with a cool dormancy, below 45F but above freezing. Some really prefer warmer winter temperatures.

You can make a list and ask in this thread if you want.

YES...

Once I switched to "Simulated Trop/Sub/Arid ect. 'WINTER'"... I've never looked back.

I grow many Punica.. and am as enamored with the plant as the day I saw the cotyledons!..

And Punica... In my cold rooms, behave 1 of two ways..

They either sloooowly go completely "dormant", actually putting on a fall show...

Or... Blow about 70 percent of their foliage.. and creep like molasses...

They really seem to appreciate this...

My ficus, serissas, and Parkinsonias all seem to have "thanked me" blatantly for this attempted simulation.

 

[Maiden69]

For example I'm in zone 5b or 6a. (depends on what map you check). Pomegranate is hardy to maybe +25F or -4 C. This is not hardy in my area. I used to treat my pomegranate as a "tropical" putting it with my orchids for the winter. It would grow year round. Growth was weak over winter, usually got pruned away in spring.

Then I found a way to keep the tree in a cool dormancy. I kept it 32Fbto 40 F all winter. ( 0 C to + 4 C) . It then would stay dormant most of the winter. It would break dormancy in March, it would get moved to windows, then outside. After a cold dormancy spring and summer growth would be MUCH more vigorous, sturdy, and better for development..

This is very interesting, I wish I had a way to keep some of my trees dormant other than buying a huge freezer. When I first started bonsai I wanted to get a pomegranate because I liked the flowering, and I was amused at all the places selling them recommending chill hours... I am from PR, a zone11-13, and we had huge pomegranate trees with no chill hours what so ever. I guess that for bonsai it probably makes sense. I just bought my first one, a very small 2 3/4" pot thing... it is staying with my tropicals this year, as close to the light as I can place it.

 

[ShadyStump]

I got one from @HorseloverFat a little while back. Left it and all my cold-blooded trees outside until temps stated getting into the low 40sF to high 30sF. It went dormant and is still sleeping soundly in the living room, and most of the others slowed down enough to adjust very nicely to indoor life. Think I've lost a few cuttings in the move, but that's all.
The one exception might be my larus nobilus which sits dead center, on top of the wooden heater vent deflector. It's getting too much heat to the roots, and growing like spring again now. Need to sort that out.

If you run into the spirit of the Rocky Mountains, tell him to send some precipitation to the rest of the dang state!

I promise it won't be found around neck of the woods too often!
But if I do, I'll put in a good word for you.

 

[Carol 83]

This is very interesting, I wish I had a way to keep some of my trees dormant other than buying a huge freezer. When I first started bonsai I wanted to get a pomegranate because I liked the flowering, and I was amused at all the places selling them recommending chill hours... I am from PR, a zone11-13, and we had huge pomegranate trees with no chill hours what so ever. I guess that for bonsai it probably makes sense. I just bought my first one, a very small 2 3/4" pot thing... it is staying with my tropicals this year, as close to the light as I can place it.

I keep my poms inside and they bloom all winter. See my latest post in the Flowers 2022 post. Doesn't seem to harm them.

 

[Maiden69]

I keep my poms inside and they bloom all winter. See my latest post in the Flowers 2022 post. Doesn't seem to harm them.

Thanks @Carol 83 , we used to have fruits from July till December, but sometimes earlier and later than that.

@Arbormancy Amatuer as mentioned above, tropicals grow year round. You can cut back, wait for the flush to harden and then cut back again. I am in TX, but I have my ficus inside my garage with grow lights on them because once in a while we get a freak night were temps will drop into the low 30's. I cut them hard mid November because I don't have that much space there. They are pushing new growth right now, once the leaves get dark green and I have a nice extension on them, they will get cut again. I don't mind if they get too crowded (even outside I grew them on top of each other - see pic below), and since I have them in the garage I don't worry too much about humidity. Indoors, you need light and extra humidity for them.

 

[August]

Indoors, you need light and extra humidity for them.

Humidity is something I struggle with, the apartment is always hot (we don't control the thermostat) and Colorado is bone dry in the winter. I have a room humidifier, but the room they're in is open to about 2/3 of the apartment before you hit doors. So far I've just been trying to keep up on the watering.

 

[Bonsai Nut]

I do the "tropical dance" here. I only bring my tropicals indoors when there is a risk of freezing temps. They're back outside right now for perhaps another week. I'll have to keep an eye on next Monday - overnight it is forecast to get down to 37 that night and I might bring them in.

But back to your question... if I'm not trying to grow out part of a tree, I try to make sure they are trimmed by late summer so I don't have any leggy growth heading into winter. However I would not trim them now because they will be partially/fully dormant and they won't recover strongly. Even if it is a little awkward, I would try to shove them into my storage area. The only situation in which I would prune a tropical at this time of year is if I had a very bright artificial lighting setup.

 

[Leo in N E Illinois]

Pomegranate - for 20+ years I grew them exactly as @Carol 83 does, bringing them into my under lights set up with my orchids. It's not a bad way to go. It was the "olden days", with now obsolete T-12 fluorescent lights you can not get anymore. Max output was 1000 ft candles from a 4 tube fixture. Ancient technology. As a result, weak growth.

The modern LEDs and even the now out of date T-5s have a much better light output. I forget how much technology has changed. No need to do the winter dormancy if you have the PAR or Lumens needed for compact growth. I really should just invest in a modern LED system and join the 21st century.

 

[August]

I do the "tropical dance" here. I only bring my tropicals indoors when there is a risk of freezing temps. They're back outside right now for perhaps another week. I'll have to keep an eye on next Monday - overnight it is forecast to get down to 37 that night and I might bring them in.

But back to your question... if I'm not trying to grow out part of a tree, I try to make sure they are trimmed by late summer so I don't have any leggy growth heading into winter. However I would not trim them now because they will be partially/fully dormant and they won't recover strongly. Even if it is a little awkward, I would try to shove them into my storage area. The only situation in which I would prune a tropical at this time of year is if I had a very bright artificial lighting setup.

I actually do have them under a very strong shop light; blinding to look into. I'm aware that as far as grow lights go, run of the mill LED shop lights are not nearly as strong or efficient as one wants, but they do respond to it and it works for me!

 

[Colorado]

Finding space indoors for tropicals is a common problem many of us face. Most trees will be fine, but @Leo in N E Illinois has outlined the potential complications.

To illustrate, though it's not exactly what most people think of, I have an Italian sweet cherry pepper that's on it's 4th winter, and really looking haggard. The regular garden variety pepper plants you find here are all the exact same species, capsicum annum, and are SUBtropical bushes. They usually only live 2 to 3 years if kept going indoors. I managed to give it a dormancy in it's 2nd winter, and it did wonderfully the next season. This year it's on its last leg, but I'm convinced I could get at least another year or two out of it if I had somewhere to safely give it a month or two dormancy again.

Something to consider is light requirements. For most trees, light plays as big a factor in triggering dormancy, or at least a slow growing rest period, as temperature. If you can find a darker cooler corner for some of your trees, that might be enough to slow them down enough to get some rest. You'll have to research each species' needs.

Also, am I SERIOUSLY the only Coloradan here NOT in Denver?!?!
I'm running out of Denverite cracks to make.

Well once you run out of Denverite cracks, guess you’ll just have to join us!

 

[Colorado]

@Arbormancy Amatuer Welcome! Lots of Denver members here, you’ll fit right in

 

[Colorado]

As far as pruning in the winter, personally I believe it depends on how much metabolic activity you are able to maintain in the shift from outside to inside. I never let my tropicals go below about 50F in order to maximize the level of metabolic activity.

Consequently, my shohin buttonwood continued growing vigorously after I brought it in for the winter. Just this past weekend I had to trim it up because it was growing into the window that it is situated by. I avoid big cuts in the winter, though. Here’s my buttonwood just for fun

 

[ShadyStump]

Well once you run out of Denverite cracks, guess you’ll just have to join us!