Repotting big maple

pbrown00

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I feel slightly bolder about summer repotting now. Do you think I can safely do it with a potbound trident maple? what kind of aftercare is needed?
 

0soyoung

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I feel slightly bolder about summer repotting now. Do you think I can safely do it with a potbound trident maple? what kind of aftercare is needed?
Leaves transpire because the rH of the air is less than 100%. The lower the rH the faster water is lost from the tree. Roots supply the water that leaves loose via transpiration. Root capacity to adsorb water is reduced/impaired. So logically, shaded during afternoon heat (when rH is lowest), dappled shade all day long, full shade, and if turgidity cannot be maintained into a humidity tent.

Regarding your trident, I think you might wait until a time when it is not extending new shoots (takes a lot of water to enlarge those cells). My acer palmatums just resumed pushing new growth so a week or two ago would have been prime. I don't have any tridents to guage the state of yours. If it is 'just sitting there' now would be good. If new leaves are popping, you might want to wait.
 
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Walter Pall

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I feel slightly bolder about summer repotting now. Do you think I can safely do it with a potbound trident maple? what kind of aftercare is needed?

With a trident maple it is a good idea in Seattle. Do not cut off too much roots, do not cut off foliage. After care it needs much less than in spring. This is one of the best things about it. The days get shorter, temperatures get down slowly, it rains more, humidity in the air is higher, much more due overnight. Water thoroughly after repotting - everything, also the foliage must be dripping wet. Then water once every day thoroughly, start feeding immediately, tree should not be in full sun all day, rather half shade, sun in the morning and shade in the afternoon is best. You must use modern substrate - absolutely no soil. You must leave the foliage on. Do not cut anything until October. Water every day all over the tree. Only on very hot days water twice. If you don't have much to do you can mist the tree several times a day.

Why does this work so well and better than in spring? Because the tree has perfect conditions now to grow roots until the end of October. This is why now! Earlier is better than later to have more time for root growth. This is eight weeks and sufficient.

Roots only grow now if there is plenty of foliage that creates energy for that. If you have not cut any branches the terminal buds will send signals to the roots with hormones called auxin that signal to grow. If that signal is not there the roots will hesitate.

The tree must get frost free over-wintering. In next spring it will start as if nothing happened.

If you repot in spring there is no foliage yet to help the roots to grow, the tree must do this out of stored energy. The energy was stored for foliage growth and not for root growth and the tree will be weakened. The foliage in spring will grow into an environment which gets worse every day, days longer, temperatures higher, humidity lower every day. The foliage will find it hard to grow well. It will quickly be too much to be supported by the existing roots - especially if you have cut off many. You have to cut short very soon after the shoots have stretched in order to avoid too much foliage mass which cannot be supported by the roots. The tree is weakened all the time by these measurement. It has a tough first summer after repotting. After two years the same again and people wonder why their trees are not doing well,m why thy do not get anywhere and stagnate.

I
 

ralf

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In the pot there should be minimum "pasive wood" and as much as possible "active" root hairs = storage of energy is limited there anyway. Trees in pots stores much more energy in the sections above pots. So there is enough energy for the growth after repot in the Spring, don't worry.
The intake of water by leaves is much lower in deciduous than in conifers. Deciduous tree without fiber/hair roots is just a piece of wood for fireplace. The level of root pruning in summer is affected by that much more than in the Spring.
One of the main factor affecting the growth of the roots is temperature of the soil/substrate. For most of the plants in our zone is the optimum temp 25-30°C. With temps close to 10 and below ie second half of Sept and in October the growth of the roots is slowing significantly.
The period from late August till end of Sept/mid October is the time of massive energy storage in vacuoles - secondary thickening. Redirecting the use of the energy from storage to growth of the roots will slowdown the development of a tree.
 

clem

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In the pot there should be minimum "pasive wood" and as much as possible "active" root hairs = storage of energy is limited there anyway. Trees in pots stores much more energy in the sections above pots. So there is enough energy for the growth after repot in the Spring, don't worry.
The intake of water by leaves is much lower in deciduous than in conifers. Deciduous tree without fiber/hair roots is just a piece of wood for fireplace. The level of root pruning in summer is affected by that much more than in the Spring.
One of the main factor affecting the growth of the roots is temperature of the soil/substrate. For most of the plants in our zone is the optimum temp 25-30°C. With temps close to 10 and below ie second half of Sept and in October the growth of the roots is slowing significantly.
The period from late August till end of Sept/mid October is the time of massive energy storage in vacuoles - secondary thickening. Redirecting the use of the energy from storage to growth of the roots will slowdown the development of a tree.
hello, what is the best period to repot palmatum tree for you ?
I recently learnt that some Japanese Master (at least one) repot in Autumn, after the autumn color leaves, to avoid the spring "sap hemorragy" from the cut on branches
 

clem

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Why does this work so well and better than in spring? Because the tree has perfect conditions now to grow roots until the end of October. This is why now! Earlier is better than later to have more time for root growth. This is eight weeks and sufficient.
Do you always let a "rootball" while repotting this palm tree ?
 

clem

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Sure, avoid cutting off too much.
ok !
do you sometimes remove all the soil (with bamboo stick or water) ?
How often do you repott this old tree ? how often do you repott some palmatum trees in "construction" ?
 

peterbone

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Thanks for the explanation Walter. I think most people would have liked the explanation up front though. It's almost like you wanted to create some controversy before you gave the explanation. I think most people are confused because this new advice from you seems to conflict with advice you've given previously on your site. For example, these posts where you repotted the same tree in March and recommend April or May to be the best time for deciduous trees not in a greenhouse.

http://walter-pall-bonsai.blogspot.com/2007/03/reoptting-of-teh-big-maple-part-1.html
http://walter-pall-bonsai.blogspot.com/2009/03/repoting-of-huge-maple.html

Of course, peoples' knowledge changes in bonsai all the time, but you act as if we can read your mind.

I'm interested to know if you think that the same can be applied to collecting trees from the wild this time of year? I've had success collecting several species in August/September with foliage and submerging them in water for a week or two.
 

Walter Pall

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Thanks for the explanation Walter. I think most people would have liked the explanation up front though. It's almost like you wanted to create some controversy before you gave the explanation. I think most people are confused because this new advice from you seems to conflict with advice you've given previously on your site. For example, these posts where you repotted the same tree in March and recommend April or May to be the best time for deciduous trees not in a greenhouse.

http://walter-pall-bonsai.blogspot.com/2007/03/reoptting-of-teh-big-maple-part-1.html
http://walter-pall-bonsai.blogspot.com/2009/03/repoting-of-huge-maple.html

Of course, peoples' knowledge changes in bonsai all the time, but you act as if we can read your mind.

I'm interested to know if you think that the same can be applied to collecting trees from the wild this time of year? I've had success collecting several species in August/September with foliage and submerging them in water for a week or two.

You are not reading everything. I clearly said that this tree needs frost free over wintering. This can only be in a cold greenhouse. So if a broadleaved tree is not in a green house this should not be done now but in spring as late as possible. There is absolutely no conflict here, you only have to read carefully.
Repotting time is exactly the same as collecting time. If you collect a broadleaved tree now you try keep as many roots as you can and do NOT cut off a lot on the top. Then yo plant it into a container. Then it must have winter protection. If it does not have proper protection it will have severe problems. So in this case the trees should be collected in late spring.

I go to this forum to show how things are done professionally in my garden. That's it. I am not interested in discussions and small talk. If you want more book a seminar with me.All the information I give I have given before on the net and on my numerous talks around the world. It is not my problem if someone has not found it yet.

If someone shows techniques and creations which are totally contradictory to conventional wisdom he is causing a lot of turmoil. I have been through this in the past forty years. I have had it. I will not discuss endlessly on the internet. And then my own knowledge and style still changes. It is not helpful if you quote me what I wrote in 2007. I would have never done late summer repotting with precious maples then.
 

Jester217300

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It like an early autumn repotting.. so i'm not sure it is a revolution ;) His tree has time to make new roots. Pines can be collected in this period because the temperatures start to go down

Early autumn is a month away.
 

clem

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Early autumn is a month away.
late summer if you prefer.. The T° are decreasing in my country and the duration of day decreases seriously too.. i have a liquidambar in my garden (in the ground) that stats to have his autumn colors (beautifull red)
 
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