Risks of Repotting

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#2
Death.

Examples of repotting outside the winter dormancy period abound, but most (the successful ones that I've seen) are done by folks that have been handling bonsai for a long time, or are working under the direct tutelage of someone with that level of experience. For me, it's not worth the risk unless the tree is in a root-compromised state, meaning the risk of death due to root work at that time of year is less than not doing the root work then.
 
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Alameda, CA
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#4
Yes, the risk will vary by species. I would repot out of season only if the risk of not repotting is high. Usually you can make some holes in the rootball to increase drainage if necessary and limp along until spring. Most trees can be slip potted off season - moved to a bigger pot with better soil and little to no root disturbance. If you do that you need to pay attention to the differing watering needs of the old soil vs the new soil. Some trees don't seem to mind as long as you don't get crazy with root work (elms, olives), but even these can suffer if you're not careful.
 

Adair M

Imperial Masterpiece
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#5
Yes, the risk will vary by species. I would repot out of season only if the risk of not repotting is high. Usually you can make some holes in the rootball to increase drainage if necessary and limp along until spring. Most trees can be slip potted off season - moved to a bigger pot with better soil and little to no root disturbance. If you do that you need to pay attention to the differing watering needs of the old soil vs the new soil. Some trees don't seem to mind as long as you don't get crazy with root work (elms, olives), but even these can suffer if you're not careful.
If you MUST slip pot out of season (or up pot out of season) use the same kind of soil the tree is already in. That way, there is no major difference between the new and old soil. The tree won’t even notice.

It’s when trees get “slipped” into fast draining bonsai soil, but the old rootball is very dense and/or staying too wet or dry. The new bonsai soil will drain faster than the old soil, and the water applied to the old rootball will run off before it gets absorbed. Roots won’t grow into the new soil because it’s so different.

Wait until it’s a true repotting time to change soil.

Olives, by the way, like to be repotted when they are actively growing.
 

sorce

Nonsense Rascal
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#8
I think I'll repot my Time-capsules Elm next week For S&G. And so it looks a little better!

Fittin to repot my Sorcihara Maple too.
Some BS.

Probly do my Smoke tree.

Probly do my Ribes.

Diggin a mulberry straight from the ground.
Removing a ground layered Mulberry.

Removing a ground layered elm.

Next week M-F is prime for this Moon.

Waiting till next for a few more.....
Boxwood, Mugo, Juniper, Spruce...

Perfect timing around the moon has been my intense study this year.
Noting very specific periods of top growth during the waxing moon.

So in searching for that perfect time to actually do the work...3 days before the full moon? 2 after? Right on?

It seems everything has a bit of an overlap period. Some trees more than others.....

Mugo didn't show (out the basket) roots till about 3 days into the waxing moon.
Sorcihara Maple already showing roots again after showing strong during last months rain and wane. And the top Only grows during the waxing moon.

So for deciduous....in that we MUST remove some foliage to prevent over transpiration....

We either must correctly time the pruning so the root Growing signals are already on their way down.

Or defoliate and LEAVE the terminal tips thru the waning moon to continue to grow roots...
Then chop them back at the new moon.
Or according to the trees particular overlap schedule, its health, etc.

I cut back the ground layered Mulberry at the last new moon...
I don't want to cut much off it...upon removal.

I have considered digging up some of the old roots and keeping the ground layer attached still to further grow roots. ....

But it's surrounded by weeds in a ditch!

Sorce
 

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