Can I grow an A. palmatum (Japanese Maple) in my area ?

[Gustavo Martins]

Still, as M. Frary said, it is never a true substitute for the outdoors. The moral of the story here: grow only what does naturally well in your growing zone. Trees age and develop much better as a result and it will be much easier on you!

I agree. I should have done my homework before...But as a newbie, I bought this plant from an impulse. As mentioned above, a few people have managed to grow these locally in their yards. So I am going to try growing outside for the time being. If that fails (the tree shows signs of poor health, lack of vigour) I will then try the fridge or just forget about this species. There's lots of local endemics to play with, although none, to the best of my knowledge, is deciduous (which I tend to prefer).

 

[MACH5]

Ok good luck Gustavo and let us know. I do love deciduous as well so I understand.

BTW welcome to the wonderful, if not crazy world of bonsai!

 

[miker]

The problem with refrigerator wintering is that is so dry.
It isn't like keeping them outside in the cold where there is some moisture in the air. Tough need to be able to bring the humidity up inside of a refrigerator or the tree dries out and dies.
There is no substitute for outdoors.

I measured the humidity several times in a couple different refrigerators that were used, and it averaged 38-40%. As long as the roots stay moist and are not frozen solid, a dormant deciduous tree should have no problem with moderately low humidity.

I have never had the problem of desiccated twigs/branches while keeping trees with moist soil in the fridge personally.

Until I moved here to SE PA, I used this technique for a number of years and it worked quite well. This approximate simulation of typical winter conditions seems to work as well as, for example, tropical plants in a properly maintained greenhouse during winter. My plants tended to look much better in outdoor conditions in the summer than in my greenhouse during the winter, but the greenhouse was enough to keep plants alive and fairly healthy in almost all cases. Artificial setups are certainly not as effective as the similar conditions outside they are intended to simulate, but they can still be quite effective.

Keep the soil moist!

 

[Gustavo Martins]

Just to say that I went for a visit to that garden I mentioned earlier this weekend and they had about 20 or so Acer trees growing there. Most were A. palmatum, and also found one that looked trident to me (this one did not have a plate on it). The A. palmatum were all still in leaf showing spectacular red/orange coloring. They were all reasonably sized trees (3-4 m height) and were surrounded by much larger tress. So essentially they are mostly in the shade. Minimal leaf scorching found.

I have hopes now for my little tree

 

[AlainK]

In the meantime, I read that A. campestre in native to Europe (including some hot countries such as Italy, Greece and Turkey). Maybe this species is more likely to adapt to my conditions over here. Does anyone has any feedback on these?

Olà Gustavo,

To me, putting Acer palmatum in a fridge, or even Ficus in an aquarium with artificial light is a lot of hassle and that usually ends up in poorly trees.

Like many here (and elsewhere) I think that one should try species adapted to their climate.

A. campestre should do well where you are, although you live on an island that is said to be very windy, but salted winds are not a problem with specimens we got here on the atlantic coast of France.

Maybe other species are more suited. I'm thinking of:

- Acer monspessulanum, very close to A. campestre, but prefers mediterranean climates
- Acer sempervirens (Cretan maple) : I don't have this species, the climate in Crete must be much warmer and less windy than in the Azores, so...

But if it's not too expensive, you can try more species: I suppose that what you can find in local nurseries must be adaptable to some extent, with care and protection.

 

[Gustavo Martins]

Olà Gustavo,

To me, putting Acer palmatum in a fridge, or even Ficus in an aquarium with artificial light is a lot of hassle and that usually ends up in poorly trees.

Like many here (and elsewhere) I think that one should try species adapted to their climate.

A. campestre should do well where you are, although you live on an island that is said to be very windy, but salted winds are not a problem with specimens we got here on the atlantic coast of France.

Maybe other species are more suited. I'm thinking of:

- Acer monspessulanum, very close to A. campestre, but prefers mediterranean climates
- Acer sempervirens (Cretan maple) : I don't have this species, the climate in Crete must be much warmer and less windy than in the Azores, so...

But if it's not too expensive, you can try more species: I suppose that what you can find in local nurseries must be adaptable to some extent, with care and protection.

Thanks for you input and tree suggestions Alan. Going to do some search on the internet for the species suggested.

It is very humid but not that windy here. The Canary Islands are very windy because they are in the trade wind belt. Here is normal, I suppose. Especially in the leeward side of the island.

 

[AlainK]

also found one that looked trident to me (this one did not have a plate on it)

Hi again,

It would be interesting to ask the gardeners there what species it is for leaf shape is far from enough to determine a species. For instance, I have two seedlings of Acer discolor (a rather rare species here in Europe but I can send you a link to the nursery where I got them if you're interested). The leaves are very similar to A. buergerianum, but they're not quite as hardy:

The leaves are slightly bigger than A. buergerianum, but since they're still growing freely, it might be a good species if they can adapt to your environment.

And perhaps you can beat me and make a bonsai from this one in fewer years

Alain

 

[rockm]

I see that the fridge technique does not gather consensus within the bonsai community.

@sorce - I don't know about your region, but over here I do not often see wine coolers on the street

Anyways, I can try to squeeze the plant inside a fridge at the Uni (my working place). My only problem is that the plant is still in a relatively large nursery pot, so it may be difficult to fit it within the fridge. I was planning to repot it next spring...

hmmm... no simple solution for my little tree

It is NOT gaining consensus in the "bonsai community." It is a half-assed solution at best. Sorry, but the claim refrigerators are really good for this are simply misleading and raises expectations. Your results may vary, perhaps tremendously. Proceed at your tree's risk.

The thing that most warm weather growers don't get about dormancy is that IT IS NOT TEMPERATURE INDUCED. Simply plunking a fully leafed maple in a fridge (which isn't cold enough to sustain dormancy or satisfy most temperate trees' dormancy requirements) does not make the tree "dormant." It temperature and light shocks it into losing its leaves yeah, but it doesn't make it go dormant naturally.

Dormancy is induced in trees BY SHORTENING DAYLENGTHS not temperature. This difference in daylight hours is more pronounced the further north, or south you go. You may able to keep the tree for a few years with such a technique, but longer term, don't expect much. These trees usually have survived because they're simply tough and adaptable species.

As for the trees that have been kept in this fashion, pictures please.

 

[AlainK]

It is very humid but not that windy here. The Canary Islands are very windy because they are in the trade wind belt. Here is normal, I suppose. Especially in the leeward side of the island.

Oops.

You're right, I was thinking of the Canaries

Had a look at the maps: Azores is roughly at the same latitude as the south of Portugal, not at the south of Morocco.

Will you post pictures of the maples that grow there? I would be very interested.

 

[AlainK]

It is NOT gaining consensus in the "bonsai community."

It is not, is it?....

It's called a dissensus (https://www.collinsdictionary.com/dictionary/english/dissensus)

On the other hand, what's the "bonsai community"?

A sum of opinions, or the right advice?...

 

[Starfox]

Out of interest how is your Maple doing now @Gustavo Martins?
Does it still have leaves or have they dropped or look like they are going to drop?
Mine appears to have gone into dormancy so if you get leaf drop it could be a good sign.

 

[rockm]

Out of interest how is your Maple doing now @Gustavo Martins?
Does it still have leaves or have they dropped or look like they are going to drop?
Mine appears to have gone into dormancy so if you get leaf drop it could be a good sign.

Leaves drop from stress. Plunking a non-dormant tree in a refrigerator and immediately exposing it to temperatures possibly 30 degrees below what it's used to and shutting off its light source is a stressful situation that will force a tree to drop its leaves. Doesn't mean the plant has gone dormant...

 

[0soyoung]

Leaves drop from stress.

The good news would be that they drop; not dropping almost certainly = dead. Abscission requires life.

 

[Gustavo Martins]

Oops.

You're right, I was thinking of the Canaries

Had a look at the maps: Azores is roughly at the same latitude as the south of Portugal, not at the south of Morocco.

Will you post pictures of the maples that grow there? I would be very interested.

Nearly the same lat as Lisbon (or San Francisco for our American readers). The light was already fading when I got to the maple area of the garden. I think I still got a good shot but I will have to do it tomorrow. I am currently away from my personal computer where the photos were downloaded.

 

[Gustavo Martins]

It is NOT gaining consensus in the "bonsai community." It is a half-assed solution at best. Sorry, but the claim refrigerators are really good for this are simply misleading and raises expectations. Your results may vary, perhaps tremendously. Proceed at your tree's risk.

The thing that most warm weather growers don't get about dormancy is that IT IS NOT TEMPERATURE INDUCED. Simply plunking a fully leafed maple in a fridge (which isn't cold enough to sustain dormancy or satisfy most temperate trees' dormancy requirements) does not make the tree "dormant." It temperature and light shocks it into losing its leaves yeah, but it doesn't make it go dormant naturally.

Dormancy is induced in trees BY SHORTENING DAYLENGTHS not temperature. This difference in daylight hours is more pronounced the further north, or south you go. You may able to keep the tree for a few years with such a technique, but longer term, don't expect much. These trees usually have survived because they're simply tough and adaptable species.

As for the trees that have been kept in this fashion, pictures please.

Hi,

worry not. I wont put my tree in the fridge. It will stay outside. If you read some of my older posts, I managed to find a local garden where they grow several A. palmatum. So I now know that they can be gronw here.

I don't know if it's temperature, day length, or any other environmental variable. My experience (as a marine ecologist) is that it seldom is only one variable that drives seasonal changes in phenology. Often it is a combination of variables. It could as well be bacteria. The effects of bacteria on many ecological patterns are only now starting to become unveiled. But I could be wrong in this case - still just learning about trees.

 

[Gustavo Martins]

Out of interest how is your Maple doing now @Gustavo Martins?
Does it still have leaves or have they dropped or look like they are going to drop?
Mine appears to have gone into dormancy so if you get leaf drop it could be a good sign.

I counted 11 leafs left on the tree They have been slowly dropping for the past month. First the scorched ones, then the healthy ones. Much faster during the last week and last weekend's bad weather had lots of them drop.

 

[miker]

It is NOT gaining consensus in the "bonsai community." It is a half-assed solution at best. Sorry, but the claim refrigerators are really good for this are simply misleading and raises expectations. Your results may vary, perhaps tremendously. Proceed at your tree's risk.

The thing that most warm weather growers don't get about dormancy is that IT IS NOT TEMPERATURE INDUCED. Simply plunking a fully leafed maple in a fridge (which isn't cold enough to sustain dormancy or satisfy most temperate trees' dormancy requirements) does not make the tree "dormant." It temperature and light shocks it into losing its leaves yeah, but it doesn't make it go dormant naturally.

Dormancy is induced in trees BY SHORTENING DAYLENGTHS not temperature. This difference in daylight hours is more pronounced the further north, or south you go. You may able to keep the tree for a few years with such a technique, but longer term, don't expect much. These trees usually have survived because they're simply tough and adaptable species.

As for the trees that have been kept in this fashion, pictures please.

I successfully kept temperate deciduous species in a refrigerator for more than 10 years when I lived in Florida. It may not be the most natural cultivation practice, but it works if done correctly (and doing so correctly is NOT at all difficult). So, if you live in Miami and must have that Japanese or trident maple, why not?

 

[rockm]

Hi,

worry not. I wont put my tree in the fridge. It will stay outside. If you read some of my older posts, I managed to find a local garden where they grow several A. palmatum. So I now know that they can be gronw here.

I don't know if it's temperature, day length, or any other environmental variable. My experience (as a marine ecologist) is that it seldom is only one variable that drives seasonal changes in phenology. Often it is a combination of variables. It could as well be bacteria. The effects of bacteria on many ecological patterns are only now starting to become unveiled. But I could be wrong in this case - still just learning about trees.

Seriously? No, bacteria has nothing to do with it. Dormancy in trees is certainly a combination of things, including the primary cause of shortening daylength.

The basics:
https://www.evergreengardenworks.com/overwint.htm
https://www.evergreengardenworks.com/dormancy.htm
https://www.evergreengardenworks.com/frzekill.htm

 

[Starfox]

Leaves drop from stress.

Agreed, even if the nursery is right next door to you often the stock has spent it's whole life under shade cloth and they still have to be nursed into their new environment. Still as Oso says, if it was still pushing new growth and or hasn't dropped you would worry.

I also agree with you that light is generally what causes change in trees, I have brought stuff in in the peak of summer before to induce flowering for example. It worked a treat but admittedly don't know if that would work on a maple.

 

[miker]

Leaves drop from stress. Plunking a non-dormant tree in a refrigerator and immediately exposing it to temperatures possibly 30 degrees below what it's used to and shutting off its light source is a stressful situation that will force a tree to drop its leaves. Doesn't mean the plant has gone dormant...

In my experience, once a temperate deciduous tree has undergone a growing season of an appropriate length, subsequent removal of the leaves and storage in the refrigerator does not cause problems for the trees I have worked with. Alternately, one can simply set the ready-to-be-dormant tree in the fridge with its leaves and they will fall off in 2-4 weeks as the tree goes dormant.

Now I really wish I would have applied the scientific method and documented a longitudinal study so I would better be able to demonstrate the efficacy of this technique.

Now living in Wyomissing, PA, I have no need to apply this technique as we have plenty of chill hours and then some for virtually any very cold hardy tree to survive here.

In the coming years, I may still conduct a long-term experiment and let all of the resulting data speak for itself. Perhaps a Japanese maple, wintered in the refrigerator for 10 seasons and documentation of tree growth and health during this period would help. From the same genetic stock, same size, etc., I could keep a "control" indoors at 58-75F each winter and another outside and protected/stored in the traditional way relative to my climate.

I really would like to do this and may get three rooted JM cuttings from the same mother plant(of the species, not a cultivar) and start the experiment this coming spring, after which each tree will be kept in identical (as close as possible) parameters and the only significant variable will be chill hours/winter storage temperatures.

My prediction: the JM wintered inside at room temperature will last two growing seasons, then go dormant when its reserves are depleted and die, the tree wintered in sheltered conditions outside will do very well and progress as expected over the 10 year duration of the experiment. Finally, the tree vernalized in the refrigerator will perform 80-90% as well as the tree kept outside during the 10 years and there is an outside chance it could perform slightly better, if harsh environmental factors (severe cold, pests, vermin, etc.) adversely affect the outdoor grown tree.

I will obviously start a thread on this subject when and if I decide to do the experiment.