ABCarve
Masterpiece
Since defoliation can do wonders for ramification, how do you know which species can have that do to them? Is there a list? What is the criteria for a species as a candidate?
Defoliation...which species??
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jk_lewis
Masterpiece
A slight correction: There's no real point to defoliation before the tree is 90% styled because its real benefit is reduced leaf size. Ramification is created by well-planned pruning.
You can defoliate most any broad-leafed tree or shrub. The effectiveness of defoliation varies. The ones whose leaves have easily seen petioles (stems) -- like maples -- defoliate the most safely. You leave a part of the petiole attached to the tree, so no damage is done to the buds you want to pop.
Those with tiny or "no" petioles are more difficult because of the danger of damage to the vestigial buds on the branch or stem when you pull or cut the leaf. Those are the buds that will create the new leaves you want. On these you may want to consider cutting the leaf itself, leaving a tiny fragment.
Needled evergreens are NOT defoliated.
Some/most?? broad leafed evergreens can be defoliated, but I'm not familiar enough with many tropical species (other than willow leaf figs) to recommend it be done routinely.
You can defoliate most any broad-leafed tree or shrub. The effectiveness of defoliation varies. The ones whose leaves have easily seen petioles (stems) -- like maples -- defoliate the most safely. You leave a part of the petiole attached to the tree, so no damage is done to the buds you want to pop.
Those with tiny or "no" petioles are more difficult because of the danger of damage to the vestigial buds on the branch or stem when you pull or cut the leaf. Those are the buds that will create the new leaves you want. On these you may want to consider cutting the leaf itself, leaving a tiny fragment.
Needled evergreens are NOT defoliated.
Some/most?? broad leafed evergreens can be defoliated, but I'm not familiar enough with many tropical species (other than willow leaf figs) to recommend it be done routinely.
ABCarve
Masterpiece
I guess that's what I meant in that the smaller leaves allow for more of them without shading.
The "most/some" and not "all" part of your statement is my problem. I guess you just have to try it on an experiment tree to find out the "if and when" part. It is a Bay tree which does not lose its leaves and has a very short petiole, that I'm pondering.
Cadillactaste
Neagari Gal
I was researching this not long ago...to do this slows the progress of growth in a tree, thus the reason ones are not to do this on a tree that isn't close to becoming a finished bonsai. Leaf reduction is considered a last step in bonsai from what I read.
Stan Kengai
Omono
The only trees besides maples that I know can be defoliated are willows, hornbeams and crabapples. Defoliation can stimulate back-budding in plants that are reluctant to do so, and thus can be used in the development phase to increase ramification. Crabapple is an example of this.
I suspect that all naturally vigorous deciduous plants can be defoliated, if only occasionally. If there is a plant that you a familiar with and you want to experiment on it, I would recommend trying a partial defoliation (either removing all leaves on a portion of the plant, or a portion of the leaves on all the plant) first to see how it reacts. If it doesn't stall, then you can consider full defoliation.
I suspect that all naturally vigorous deciduous plants can be defoliated, if only occasionally. If there is a plant that you a familiar with and you want to experiment on it, I would recommend trying a partial defoliation (either removing all leaves on a portion of the plant, or a portion of the leaves on all the plant) first to see how it reacts. If it doesn't stall, then you can consider full defoliation.
Good question!
Unfortunately, there are no easy answers.
Take Japanese Maple, for instance. Some you can, some you can't. No, I don't have a list.
I asked Boon. He said, "The fancy varieties usually don't bud back, so don't defoliate. You can cut back, but don't defoliate". The "ordinary" varieties, you can defoliate. How do you know which are which? I haven't a clue. I have a "Seigen". He said not to defoliate. I'm thinking if it is a named cultivar, don't risk it. Unless you are informed otherwise by an experienced practitioner.
I have seen videos of partial defoliation. Japanese maple, for example. Cut back to two leaves on a stem. Either cut one leaf off leaving the other, or cut each leaf in half. That way you reduce the leaf surface but keep the sap line active. Either way increases the light into the interior of the tree.
Trident maple: defoliate all you want. I've defoliated twice so far this year. Will probably do another.
Zelkova also defoliate well. I've done it twice this year, too. Very tedious to do them, very short stem. Don't pull them off, you'll destroy the buds.
Unfortunately, there are no easy answers.
Take Japanese Maple, for instance. Some you can, some you can't. No, I don't have a list.
I asked Boon. He said, "The fancy varieties usually don't bud back, so don't defoliate. You can cut back, but don't defoliate". The "ordinary" varieties, you can defoliate. How do you know which are which? I haven't a clue. I have a "Seigen". He said not to defoliate. I'm thinking if it is a named cultivar, don't risk it. Unless you are informed otherwise by an experienced practitioner.
I have seen videos of partial defoliation. Japanese maple, for example. Cut back to two leaves on a stem. Either cut one leaf off leaving the other, or cut each leaf in half. That way you reduce the leaf surface but keep the sap line active. Either way increases the light into the interior of the tree.
Trident maple: defoliate all you want. I've defoliated twice so far this year. Will probably do another.
Zelkova also defoliate well. I've done it twice this year, too. Very tedious to do them, very short stem. Don't pull them off, you'll destroy the buds.
MrFancyPlants
Masterpiece
I was just hacking back my bay this morning. Good luck achieving any sort of natural ramification, the growth habit is just too coarse. If it didn't help out with the pasta sauce, I would have given up on it long ago. You would need a huge tree to make an acceptable bonsai out of a bay. In fact I believe I have just talked myself into converting mine into a house plant.
They do backbud, but I wouldn't remove all of the leaves and I would only remove most of them every once in a while. They can hang on to their leaves for 3 or 4 year, so even a partial defoliation would set them back a ways.
Post a picture and maybe Jim will elaborate on a careful pruning plan.
They do backbud, but I wouldn't remove all of the leaves and I would only remove most of them every once in a while. They can hang on to their leaves for 3 or 4 year, so even a partial defoliation would set them back a ways.
Post a picture and maybe Jim will elaborate on a careful pruning plan.
Paradox
Marine Bonsologist
I believe chinese elms can be defoliated?
I learned last night that some ficus can also be defoliated at the right time in the right climate.
I learned last night that some ficus can also be defoliated at the right time in the right climate.
There was a good article by Bjorn about defoliating maples. Even if your tree is not fully styled, partial defoliation may be helpful to ensure that light and air reach the inner growth to keep it strong. For example, with standard japanese maples, I believe he said to cut off one of the leaves of each branch end pair at the petiole, and if necessary, cut the second leaf of the pair but cutting part of the leaf itself off.
Brian Van Fleet
Pretty Fly for a Bonsai Guy
Sure, but why would you?
Vance Wood
Lord Mugo
The real bottom line is if you can't find it in a book/publcation then ask first. Someone here probably knows. Make sure you are not listening to someone with no tree to back up the advise.
There are trees that cannot or should not be defoliated. Trees with compound leaves cannot be defoliated. Japanese Beech cannot be defoliated. Small Leaf Linden cannot be defoliated. Don't even think in terms of the connifers they are a totally different ball game. I know there are many more but I have provided only a few. Hopefull you will get the idea that defoliation is an exception other than a rule and that there are more trees that cannot be defoliated than can be. Mostly I have seen defoliation practiced only on the Japanese Maples (except the Lace Leaf varieties which--- you guessed it; cannot be defoliated). This practice is really only for more advanced trees in development.
thumblessprimate1
Masterpiece
I've defoliated a dissected leaf Japanese maple in the summer, Inabe shidare. Sorry, no pic to back it up. It had lots of sun scorch.
it seems you are asking specifically about Bay and I have zero experience. There is at least one conifer...although a deciduous one, Bald Cypress, that can be defoliated and it works well if one would like to wire train in the summer.
I have found partial defoliation to work better on J. Maples.
I have never been totally satisfied with the results of defoliating tridents...although it is certainly a common practice...I suspect my trees are just not ramified enough to enjoy the benefits.
I have found partial defoliation to work better on J. Maples.
I have never been totally satisfied with the results of defoliating tridents...although it is certainly a common practice...I suspect my trees are just not ramified enough to enjoy the benefits.
Paradox
Marine Bonsologist
Ive noticed mine has leaves that are a bit larger this year so thought it might be done to reduce them.
I know trimming them regularly seems to do alot for ramification so perhaps that is a better way to approach it?
Vance Wood
Lord Mugo
Interesting, here is an exmple of quoting something I had heard.
GrimLore
Bonsai Nut alumnus... we miss you
If you are talking about a Laurel they can take a hell of a good cutback in Spring and come back full force in 2 - 3 weeks. There is a guy local that makes topiary out if them... If that's what it is, treat it like a shrub. I would not do a complete defoliation except for heavy Spring work.
Grimmy
Grimmy
FrankP999
Shohin
What about Japanese birch? Can they be defoliated?
Thanks
Frank
Thanks
Frank
thumblessprimate1
Masterpiece
I found pictures at ibonsai of a lace leaf maple that had problems resulting in leaf drop. Leaves grew back. Click on link.
I'll try to defoliate mine and document the result this week if it doesn't rain.
0soyoung
Imperial Masterpiece
There is a bud, an axillary bud, at the base of a broadleaf leaf 
confused. The branch/tree can be defoliated as long as the leaf can be removed without damaging the axillary bud - the branch/tree will leaf out again. The axillary bud, once released, will produce a new shoot.
It is irrelevant whether the broadleaf plant is deciduous or evergreen as to whether it can be defoliated or not. Azaleas, both deciduous and evergreen can be defoliated. Oaks, both deciduous and evergreen can be defoliated. Etc.
Leaf size reduction is not inherent with defoliation - it occurs only with certain species. Often it is just and illusion because leafs enlarge slowly after emergence (this is the case with zelkovas, for example).
Any deciduous specie, even a conifer, can be defoliated - bald cypress (taxodium distichum) for example.
There are even some evergreen conifers that also can be defoliated - crypotomeria, for example.
"... but why would you?"
-- Brian VF
confused. The branch/tree can be defoliated as long as the leaf can be removed without damaging the axillary bud - the branch/tree will leaf out again. The axillary bud, once released, will produce a new shoot. It is irrelevant whether the broadleaf plant is deciduous or evergreen as to whether it can be defoliated or not. Azaleas, both deciduous and evergreen can be defoliated. Oaks, both deciduous and evergreen can be defoliated. Etc.
Leaf size reduction is not inherent with defoliation - it occurs only with certain species. Often it is just and illusion because leafs enlarge slowly after emergence (this is the case with zelkovas, for example).
Any deciduous specie, even a conifer, can be defoliated - bald cypress (taxodium distichum) for example.
There are even some evergreen conifers that also can be defoliated - crypotomeria, for example.
"... but why would you?"
-- Brian VF
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jk_lewis
Masterpiece
I've never owned or defoliated a Zelkova, so I can't say, but I have defoliated a large number of other tree species -- sometimes as often as two or three times a summer in N. Florida. I have to say that in every case, except when done in late spring or too early in the summer, when leaves can come back even larger than before defoliation, the leaves reduced significantly.
