Tropical bonsai in cold climates

Happy new year to everyone!

There was a discussion on another forum about tropical bonsai, and someone posted the comment "why do people in the northeast grow tropical bonsai?" Of course there are a variety of reasons...for example, people may just like a particular plant (serissa, rain tree, etc). The other big reason is "it gives people something (bonsai related) to do during the winter".

I've been thinking about this a lot lately. As you may know, I've only been doing bonsai for about 2.5 years. When I took my first class in fall 2010, I acquired 2 tropical plants - a jaboticaba and a brush cherry. Even though we worked them pretty hard in the fall, they both came back strong during the winter, and both required pinching several times, along with de-wiring and some re-wiring. So I figured that having a small collection of tropicals would allow me to speed up the learning process a bit, by giving me some bonsai stuff to do during the winter.

Since then I've acquired a few more plants...tiger bark ficus, a couple of willow leaf ficus, water jasmine, grewia, buttonwood. However, what I'm finding is that, for the most part, the plants stop growing or slow down so much during the winter that there's really nothing to do other than watering. And though the willow leaf ficus look pretty good (see https://ibonsaiclub.forumotion.com/t12309-willow-leaf-ficus-1 and https://ibonsaiclub.forumotion.com/t12318-willow-leaf-ficus-2), many of the other plants are experiencing yellowing and dropping leaves, and look pretty terrible. Even the brush cherry and jaboticaba, which did well the first winter, have had a hard time this whole year.

I guess I should get to the point of this post. For those of you growing tropicals in colder climates, and especially in places like upstate NY, the midwest, New England...have you been able to create conditions that allow your plants to not just survive, but actually grow during the winter? If so, can you talk about which species have worked well, and what your growing conditions are like? If you haven't been successful, I'd like to hear about that as well. Maybe I'm trying to do the impossible under my conditions.

In my case, the first 2 winters I was using fluorescent lighting. This year I've switched over to a 400 w metal halide, so I don't think the lighting is the primary issue. Temperatures range from low 60s at night to 75+ during the day. Humidity may be an issue, during the colder periods it ranges between 30-40% a lot of the time. There's not much else I can do, as I live in an area that's very cloudy during the winter...plus I don't have a greenhouse or even a large window available.

Thanks for any suggestions you can provide!

Happy New Year!

Ficus and other tropicals do (or will) slow down if they notice a lack of light and lower temperatures. What I've done is I've replicated the great outdoors, but in a spare bedroom. Using a combination of T5 and T8 lights over top humid, warm setups, I can get my trees to actually flourish year round and not slow down at all. The trees get no natural sunlight, all artificial.

its deffinately not impossible, but could get kind of expensive in materials depending on how far you want to take it...i personally bring my tropicals inside for winter eventhough i probably dont need to where i live...for me though, its not so much about the foliage but the roots...i transplant and do root-work late in the season, and then bring them indoors where they can recover...the foliage that grows during this time is pretty lanky and weak...but, i dont care much since my goal is to give them a head start for spring...so when spring gets here, i just cut off any of the scraggly foliage when i move them outside...they grow so fast anyway, for me its not worth the money and the space it would take to set up an elaborate grow system...if, however, this is something that would be worthwhile for you, i would suggest going onto forums where they specialize in growing a certain budding plant completely indoors under artificial conditions...those guys know everything there is to know about growing stuff indoors...

I've got a few trees (ficus, crassula and sageretia) under a 400w MH and a few fluorescents. I have a humidifier set up so a fan gently wafts the steam from it over the trees. They grow like weeds over the winter. Only time they slow down is for a very short time in both spring and fall when acclimatizing from indoor to outdoor environments. Only real problem I have during the winter is pests. All summer long they're practically bug free but once inside the scale come out. A few treatments and a careful eye keeps them under control however.
As for why I grow indoors. I like having a little corner of summer in my apartment over the winter. Watering, trimming, wiring and sometimes repotting while sitting under that 400w is very refreshing while it's grey and freezing outside. My question would be, if you have the room, money, and passion, why wouldn't you want some trees to work on over the winter?

I've been having a lot of fun experimenting with my indoor setup, and although I have had a little spider mite issue, I've been very pleased with my new growth and even leaf size with this setup:
https://ibonsaiclub.forumotion.com/t12302-indoor-tropical-led-experiment

I am not sure if the real gain is from the lights that I purchased or from the heat an humidity from having them enclosed in the aquarium. Although Ryan's tents are more practical for a larger setup, I think my setup could work very well in an office environment.

With a MH, I think you are right that your plants are not slowed by low light, but by the lack of heat and humidity. A lot of these tropicals like it much warmer than 75.. try 80 or 90.

MrFancyPlants wrote: A lot of these tropicals like it much warmer than 75.. try 80 or 90.

I do have a thermometer with my plants and it's currently 80 F at pot level, warmer up in the "canopy" closer to the light.

I guess I'm trying to figure out if it's worth the effort to me. As it stands now, for the most part the tropicals don't really get going until they get put outside in May. And of course, by that time all the hardy plants are in full growth and demanding attention. So unless I can figure out a way to get the tropicals growing during the winter, there doesn't seem to be a good reason to keep struggling with them.

I'll have to look into ways of keeping the growing area a little warmer and more humid. Problem is if I raise the humidity too much in the room, I'll get moisture condensing on the windows/walls (got down to 12 F, -11 C here last night...). So I'll have to see if there's a way to partly enclose just the growing area.

Please keep thoughts/suggestions/experiences coming.

Definitely check out Ryan's enclosures. It shouldn't be too hard to put a tent around your existing setup. It doesn't need to be air tight, but you might need to get creative with the top portion since I have heard that MHs get pretty hot. I think you will be surprised how quickly your plants will respond.

I just moved around some trees so that I've now got two little greenhouses. One with 8 T8 bulbs above it, and the other with 8 T5 bulbs above it. Both with 90F temperatures and 99% humidity.

Chris

Here is a shot today of my tropicals on their bench inside for the winter. They shiver the months away in this south facing window. No supplemental heat or humidity. Like you I have experienced far less growth then last year but I also think we've had fewer sunny days with all this snow. The trees enter a semi-dormancy (except the Pomegranate which you can see on the little pedestal) I've had some growth on the willow leaf, and on some of my Bougey clones but other than that all my trees just sort of stop until March.

As Bill mentioned to you last year; I just try to keep them alive 'till spring. In fact adjusting down the watering is a bit of a skill I've had to learn. I do a bit of wiring here and there. The real rocket shot growers like the Raintree take wire well at this time of year.

I love to garden and having an indoor green area is balm for my soul at this time of year (just look out my window!) I find that in summer my tropicals actually out grow the deciduous trees, some (Raintree and Acacia) by a factor of say 3 to 1. So I can get good development on them even though I don't have the sort of "full" growing season they enjoy in southern climates.

-Jay

I have two tropicals I bring into my home office for the winter. They sit on stands by a window. I just water them an they grow slow, but they still grow. The window gets pretty bright afternoon sun. My house temp is 72 degrees F at all times. Some people say that roots have to be so warm for them to grow, but mine grow at 72 degrees.

Does this help -

max 90 deg F from 10 a.m until 12.00 lunch time.
min. 70 deg.F after 6.00 p.m to 6.00 a.m.

Humidity - 80 % from 6.00 p.m to 6 a.m.
60 % for the rest of the day.

Some light wind, and pots that dry out every other day.

It's an average of our outside conditions until the end of March.

I actually use the conditions above for repotting in January to February.
My trees are usually heavily potbound after 1 year of growing.
Save for pines, they run on a 3 year repot cycle.

From what I am reading and have read, all you are trying to do is replicate simple -cool weather- tropical conditions.

Does anyone test the Lux / candlelight factors for their trees ?
Lesniewiz has a page of Lux strength needed for good growth indoors.
Best to you guys.
Khaimraj

* Fukien tea leaves my be affected by changes in air humidity.

drgonzo wrote:Chris
As Bill mentioned to you last year; I just try to keep them alive 'till spring.

See, that's the issue for me...I don't want to "just try to keep them alive"...which really means (at least with my current set up), watch them slowly go downhill through the winter. And if I have to jump through all kinds of hoops to maintain 85 deg temps and 80% humidity to get the growth I'd like during the winter, then it's probably not worth the effort to me. That's a decision I have to make, of course, but it's why I'm soliciting opinions, hoping that maybe by tweaking my growing area a little bit I can at least get the plants growing.

You have one benefit over me, and that's the big window. So by March your trees can start to respond to the increasing day length and, particularly, the strengthening sun. I have to keep my plants in an area that has essentially no natural light. Even with the MH light, the light intensity is not near what you get with actual sunlight.

drgonzo wrote:I love to garden and having an indoor green area is balm for my soul at this time of year (just look out my window!)

Me too, but having a green area that slowly declines through the winter is anything but a balm for me!

MrFancyPlants wrote:Definitely check out Ryan's enclosures. It shouldn't be too hard to put a tent around your existing setup. It doesn't need to be air tight, but you might need to get creative with the top portion since I have heard that MHs get pretty hot. I think you will be surprised how quickly your plants will respond.

MH fixtures get very hot, so it will require some care and creativity. I am going to look at my setup and see if there's a way to enclose it more effectively so the temp and humidity can be maintained at a higher level.

Ryan wrote:I just moved around some trees so that I've now got two little greenhouses. One with 8 T8 bulbs above it, and the other with 8 T5 bulbs above it. Both with 90F temperatures and 99% humidity

Are you still using humidifiers in the enclosures? If so, what type? I don't really have a convenient place to put a bunch of these "mini-greenhouses" so I'm going to just have to try to modify my current setup. I might be able to incorporate some of your methodology, though.

Thanks for the suggestions. Still looking for additional input!

coh wrote:
Are you still using humidifiers in the enclosures? If so, what type? I don't really have a convenient place to put a bunch of these "mini-greenhouses" so I'm going to just have to try to modify my current setup. I might be able to incorporate some of your methodology, though.

Nope, no humidifiers at all. When I water the trees then close up the enclosure the humidity is given off that way with the evaporating water.

Guys,

I forgot to mention that for us - being 11 deg away from the equator - from December to Februay's end, trees as bonsai don't really grow, in fact a few like our local ficus plants actually sleep.

Additionally, the 70 deg.F low is the air temperature, the pot temperature may actually be lower by 5 or 10 deg.F.

So unless you are on the equator where there is no real change in anything, you might be forcing trees that normally sleep for at least 2 months, if not three to grow.
This is why I can repot January 2nd and not have to do anything until February's end or so.

You might be breaking the normal evolved cycle.

Lastly, on our side with heavy rain, growth stops as well/
Later.
Khaimraj

Khaimraj Seepersad wrote:Guys,

I forgot to mention that for us - being 11 deg away from the equator - from December to Februay's end, trees as bonsai don't really grow, in fact a few like our local ficus plants actually sleep.

Additionally, the 70 deg.F low is the air temperature, the pot temperature may actually be lower by 5 or 10 deg.F.

So unless you are on the equator where there is no real change in anything, you might be forcing trees that normally sleep for at least 2 months, if not three to grow.
This is why I can repot January 2nd and not have to do anything until February's end or so.

You might be breaking the normal evolved cycle.

Lastly, on our side with heavy rain, growth stops as well/
Later.
Khaimraj

Good points, and I have been considering this as well. When you say your ficus "sleep", what exactly do you mean? Do they just stop growing but maintain healthy foliage? Does the foliage gradually yellow and drop off, or even drop all at once, leaving the tree leafless for a couple of months?

If I could figure out how to grow my tropicals so that they experienced a 2-3 month rest early in the winter (say Oct/Nov/Dec), but then came back into healthy growth, that would be great. But how to do that, especially with a mixed collection? I've looked for information about the growth habits of the various species in their native environments, but a lot of it is vague and contradictory. One of the things I'd like to get people posting here would be how they handle this in the colder climates. It would be nice for there to be a single place where you could go and find out that, for example, brush cherry (or whatever species) really needs a 2-3 month dry period (or whatever) during which it drops its leaves.

The species I have are the following:

jaboticaba
brush cherry
willow leaf ficus
tiger bark ficus
water jasmine
buttonwood
grewia

If anyone can offer specific advice on the above, based on either/both their experience in bonsai culture or knowledge of their native environment, it would be very helpful. Thanks!

Chris,

Jaboticaba - is listed as from near the tropic of Capricorn [ Sao Paolo ] and Minas Gerias [ if Wikipedia is correct.]
An area elevated from 1200 to 3000 feet.
[ Florida exists just after the Tropic of Cancer ]

Ask the Brazilians on the IBC, but this could be another Sub-Tropical. [ I also have an atlas in front of me -Philip's ]

Tiger bark ficus, and water jasmine are from the Eastern side and you can simply write to Budi for the day to day information. He is on IBC.
Wrightia religiosa is listed as from Malaysia, almost on the equator, possibly a true tropical.

Buttonwood [ Conocarpus erecta ] is found down here. Sleeping presently, no new growth. So you could use the factors I left earlier.

Grewia is it Grewia occidentalis ?
If so it is from South Africa -- listed for your zones 9 to 10
South Africa is below the Tropic of Capricorn and mountainous, so Grewia is most likely Sub-Tropical.
Once again just ask some of the South African folk on IBC by p.m.

Grewia does not do well on our side [ zone 13 ?]

Brush cherry ? any latin names ?

I would suggest you work with expendable cuttings, in order to learn what works, but you probably have gone to specimens, and that can be a little heart in mouth.

The Ficus I have are all not growing any new leaves and have not done so for a few weeks. Benjamina, Priminoides [ Spelling ? ] Retusa [ macrocarpa ?] and something called a ginseng ficus [ ? ] grows a large root/trunk, but these are cuttings.
Hope this helps.
Khaimraj

Khaimraj, thanks for your suggestions...will follow up on them.

Sorry was lazy about the latin names...

Jaboticaba = Myrciaria cauliflora? Not sure, obtained from Bill V.
Brush cherry (dwarf) = eugenia myrtifolia (or syzgium paniculatum) again from Bill V.
Grewia = grewia occidentalis

Designating plants as tropical vs subtropical is only somewhat useful, as there are large variations in climate within each category. For example, subtropics can have either rainy winters or rainy summers. It may well be that I'm expecting too much out of these plants (to have them grow through the winter, or at least part of the winter). Fortunately, I don't have a lot of $ invested, they're all established plants (as compared to young cuttings or seedlings) but most were in the $20-$25 (U.S.) range...I intentionally kept the costs low since these are experimental. The buttonwood (from Puerto Rico) and the larger willow-leaf ficus were a bit more expensive.

Still looking for input from growers in the colder areas...I know you're out there!

Chris

Khaimraj Seepersad wrote:Chris,

Jaboticaba - is listed as from near the tropic of Capricorn [ Sao Paolo ] and Minas Gerias [ if Wikipedia is correct.]
An area elevated from 1200 to 3000 feet.
[ Florida exists just after the Tropic of Cancer ]

Ask the Brazilians on the IBC, but this could be another Sub-Tropical. [ I also have an atlas in front of me -Philip's ]

Tiger bark ficus, and water jasmine are from the Eastern side and you can simply write to Budi for the day to day information. He is on IBC.
Wrightia religiosa is listed as from Malaysia, almost on the equator, possibly a true tropical.

Buttonwood [ Conocarpus erecta ] is found down here. Sleeping presently, no new growth. So you could use the factors I left earlier.

Grewia is it Grewia occidentalis ?
If so it is from South Africa -- listed for your zones 9 to 10
South Africa is below the Tropic of Capricorn and mountainous, so Grewia is most likely Sub-Tropical.
Once again just ask some of the South African folk on IBC by p.m.

Grewia does not do well on our side [ zone 13 ?]

Brush cherry ? any latin names ?

I would suggest you work with expendable cuttings, in order to learn what works, but you probably have gone to specimens, and that can be a little heart in mouth.

The Ficus I have are all not growing any new leaves and have not done so for a few weeks. Benjamina, Priminoides [ Spelling ? ] Retusa [ macrocarpa ?] and something called a ginseng ficus [ ? ] grows a large root/trunk, but these are cuttings.
Hope this helps.
Khaimraj

coh wrote: It may well be that I'm expecting too much out of these plants (to have them grow through the winter, or at least part of the winter).

I think you may have put your finger on it Chris. We're lucky up here in that we can overwinter many tropicals successfully yet a bonsaiist in a tropical climb cannot over winter temperate stock as easily. We're asking zone 11 and higher plants to grow in zone 6 and we can only acomplish this by subjecting them to indoors conditions. Even with all the bells and whistles we can come up with to make life more comfortable inside for them its still not "home" up here until summer for these species. We're lucky they can power down indoors and make it through these long dark winters. Cripes I barely make it through the winter and I'm a native!

I ask nothing more of my tropicals then I do my deciduous trees going through their dormancy right now....Just survive. Actually growth in winter tends to be so poor that I lose much of it to the direct sun of late spring so In a way I'd rather they just sit tight and hang back on any vigorous growth until conditions are more suitable.

Yet the tropicals give me some green to enjoy and my conditions are decent indoors but still my Acacia forrest looks like its stuck in perpetual fall and my large Bougey is half defoliated... par for the course..Yet I am careful, as you know, to try to pick species I know will work with my indoor conditions (hard water and cold) and I avoid those who would just suffer with what I can offer indoors throughout the winter.

If my Maples held on to (even some) of their leaves all winter yet didn't grow, I would still enjoy them as I do my Raintree and I would wait patiently for spring so I can get back to "work" on them as it were.

-Jay

Hey Chris,

I think I may have an answer for you. I have 3 raintrees, 1 medium size, a small shohin and a seedling that just sprouted this year. They all go outside as soon as possible and come inside as late as possible in the year. As soon as they come inside, the shohin and the medium size slow down and drop a ton of leaves despite the fact that I have a 9 foot south facing window with no blinds or curtains. The seedling however, which for some odd reason had a rough time after sprouting so I kept it semi-shaded, has been growing like a weed since I brought it in. What I think happened is that the seedling never got used to the sun's strength, so the light my window provides appears to be enough for it to grow well. Another little curveball is that, my medium raintree is VERY strong and has tons of buds throughout but has only extended 1 of them with new growth. This new growth now has 7 sets of leaves and extending, so while the old leaves that were used to exterior light are now dropping off, these leaves are not.

Ryan mentioned that his trees receive only artificial light. That may be the difference and therefore the issue we're experiencing. We're bringing our plants out and then bringing them inside for the winter. No matter what light we use while indoors (which I use no supplemental light) they'll still experience a change in light intensity at a minimum among many other factors. What do you think? Does this make sense?

Have a great weekend!!!!
Sam

Chris,
My approach to your growing situation would be to keep the plant area much warmer. I would try to hold your night temperatures above 65-68F.
I would also make sure that the metal halide light is not getting your plants too hot. Leave a thermometer at the top of the foliage height. Keep temperatures below 95F or the plants may suffer.
Humidity is definitely helpful and making some sort of enclosure will help keep humidity levels higher and your plants will be healthier.
However of all the factors that you could modify this one is to my mind the least critical. If you have good light and the proper temperatures I think you will be pleasantly surprised.
Let us know how it goes.
Jerry

West Indies? Don't you live in the tropics?

Jkd2572,

the West Indies is the proper name for the area sometimes loosely called, the caribbean. The postal address should read something like this,

Harold Highbottom
21 z St.Mary's road,
San Peterson.
St. Lucia,
W.I.

yes, I believe I am in a Tropical zone, no chance of frost.
Later.
Khaimraj

Chris,

for the two years, I lived in Philadelphia, I grew an indoor oak [ was Niicodemia d. ] and a Malpighia punicifolia, with nothing more than a south window and in a room heated by a water steam radiator to just about 75 deg.F. Had no problems, no leaf drop or other.
Both plants [ given away ] are the mother of all the shrubs I have of that type.

In Florence, Italy, I did the same with Fukien teas, Chinese elms, pomegranates, and the zelkova slept outside on the window sill. Again had no problems and Florence is dull from December to April or so.
South and East light, room again around 75 deg.F.

I try to make sure I know where something comes from so I don't harm by expecting growth when there shouldn't be any.
Bougainvilleas are sub-tropical, the neighbour's shrubs are not actively growing, nor are their Murraya p. fences.
Same goes for crepe myrtles, however the tamarinds are still active.
The high yesterday according to my min-max thermometer was 84 deg.F and today's low is 68 deg.F with a drizzle or two last night, time 5.55 a.m and the humidity is 79%.
The soil temperature maybe be lower by 5 to 10 deg, and if close to 55 deg.F, growth will slow or stop for Tropicals.[ Note there is a difference Sub-Tropical and Tropical.]
Later.
Khaimraj

* I live on a hill, facing North East, in a wind channel, and the house blocks the direct sunlight until around February 26th, additionally, the winds come from over large areas of green.
Folk in the plains stay hotter and I seldom go North for the winter months - chuckle.
Seen the misty images I left in The Lounge?

By the way Trinidad is a cloudy island, all year round and no way as popular for Tourists as the lower and flatter Barbados.

Very interesting discussion, indeed

coh wrote:

Khaimraj Seepersad wrote: ... ...You might be breaking the normal evolved cycle... ...

Good points, and I have been considering this as well... ...

Khaimraj Seepersad wrote:... ...I try to make sure I know where something comes from so I don't harm by expecting growth when there shouldn't be any... ...

I am also seriously considering the above queries...
I grow indoors water jasmine 1,5-year seedlings (wrightia religiosa) and willow leaf ficus (ficus salicifolia).
I use 2 T5 18W fluorescent lamps of 55 cm each. My husband has settled a wooden two-shelf structure which is enclosed by clear thick plastic sheet, no top covering. I also use plates containing some water which slowly evaporates.
I try to have the lights on for about 18 hrs/day but often the lights are on all day long. The plants grow quite well and I'm happy with their rate. But is this non-stop growth natural, I wonder...
My only problem is that ficus drops its new leaves. Yesterday I used a fungicide on the substrate because it has formed enough spots of white mold. Wrightia shows nothing of this sort. And I suspect that these new leaves are kind of weaker than normal.

Alexandra,

you have two choices -

[1] Write to our members in Malaysia - Budi and ask just where the Wrightia comes from, plains, mountains, or other and about the periods of growth.

[2] Ask where the Ficus came from and how cold tolerant it might be.

Best to you for the New Year!
Later.
Khaimraj