AusBonsai

Hey All,

Planning to repot my oak and maples this weekend, though they've already broken out in to leaf ... is it too late to repot?

- Daniel

root pruning could be dodgey--

Let the growth harden now, IMO. Now is not the time. Late Spring will be fine.

It depends how brave you are feeling Daniel.
Conventional wisdom is that root pruning when leaves are growing is certain death but if you ask the question the people who offer that wisdom have never done it. They heard it from someone.
Here's a thread I started some time ago when I suspected we could root prune far more broadly than the currently accepted narrow windows. You can see that some very experienced growers came out of the woodwork to admit they had successfully repotted trees well outside the normal window. viewtopic.php?f=12&t=18983&hilit=late

I'm still not going to take responsibility for your trees but I have even further explored out of season repotting here and have had very few losses. Just keep a record of what, when and how and results to add to our growing store of knowledge.

A couple of years ago I received 40 bonsai that were all in horrible mix and in desperate need of repotting, I repotted all of them on the 15th of November and had zero losses, kept them in the shade for a week and monitored their watering closely and they all powered on.

Keep it to a gentle root prune and with good after care.

Thanks for all the replies and link! I was feeling brave, less so now, haha.

My maples are from air layers last year. Might start with those, in the arvo, with very light root pruning.

The oak I'm more precious about, so will do that tomorrow arvo, when it's cooler, might be more of a slip pot than traditional repot. It's only 4 years old so don't imagine it'll be too root bound.

Will update with pics with before and after and to track progress later.

Thanks again!

Change of plan, short on time, I started with my Oak, which was quite root bound - shows what I know, haha. Photo sequence below:








(these roots broke off with my raking, thought I was being super careful)




(had I re-potted prior to leaves coming out, I would have root pruned much harder ... being nervous left a fair bit on ... good decision?)


(think next year will go into a bigger pot either way)

I don't think you have anything to worry about. I would have trimmed a bit more even with the leaves on.
Don't panic even if the existing leaves dry up. Trees are amazingly resilient and have ways of surviving so they can drop leaves in tough times and grow another lot after the stress is over. Just don't let it get dry for a few weeks at least.
good luck

Thanks Shibui, few weeks, can do. Thinking I'll leave it in the shade for a week or two, then move it out to its normal sunny spot.

When would be a good time to feed it?

- Daniel

I use osmocote in the mix so mine all get fed immediately after repotting no matter how many roots have been removed which makes me wonder about the rule not to feed plants after transplant.
In any case, with minimal root reduction like you have done here I think you should be able to feed immediately.

Feeling a bit to brave, I've re-potted my air layered maples ... was amazed that the larger of the two had a root about 1.5 meters long!!!













Might have trimmed too much back ...



Thought I'd scatch the trunk to encourage(?) some more roots



Final line up of all three bonsai repotted, with a little succulant to keep them company!

Looks like the repotting wasn't too stressful as the oak and larger maple have new leaves shooting out, along with maintaining all the previous leaves!

Maybe I could have been more brave with the trimming. Next year will cut back harder!

Thanks again for the encouragement!

- Daniel

Update: Two weeks on ... all bonsai doing great!!!



Should I trim back some branches, or focus on growth and style next year?

- Daniel