Repotting/Root Pruning English Oak

[CaptainKazz]

Hello everyone

I've been trying to find some information on repotting and root pruning my English Oak bonsai. I keep finding conflicting articles and no one can really give me the information I'm looking for, so I thought I'd ask for some help here

At the moment it's living in a rather large pot, the pot it came in as a starter as a matter of fact, and I'd really like to move it to a much shallower (but still rather large) bonsai pot I have left over from repotting my maple last year. I'm not really sure how much is safe to take off the root ball though, as I've heard many people say that they're quite sensitive to root pruning.. The new pot is about half the size of the old one (but I'm not sure if the root ball actually fills the entire pot it's in now)

The main impression I'm get is that repotting/root pruning for the English Oak should be done before the buds go into leaf, but some people have said otherwise so I'm a bit confused here too...

So does anyone have any advice for me? I love this tree and I want to give it the absolute best chance of survival

[Bougy Fan]

You probably should be doing it soon if not already. I have already potted most of my deciduous trees here in Brissy. Once the buds just start to open is the ideal time - just treat it like all other deciduous trees. Being that they are usually a cold climate tree I would downsize pots gradually instead of drastically reducing the depth in one go

[CaptainKazz]

I'm going out this afternoon to get some soil for my other trees, so I may look for a transition pot of some sort. I'm getting ready to do it soon, as it's starting to warm up pretty quickly...

[Bougy Fan]

Just make sure it's a free draining mix. I have my maples and horbeams in either straight diatomite/zeolite or mixed with some potting mix. I have lost a few liquid ambars due to a gluggy organic mix that didn't drain well.

[CaptainKazz]

Will do, I prefer to make a mix rather than just go with a basic retail bag
and I think I still have some zeolite hanging around...

[Bougy Fan]

I think diatomite is more important than zeolite - I have only just started using zeolite since I found a reliable source up here. Zeolite will retain some nutrients - but I think diatomite is more important to hold some moisture but more importantly open up and aerate the mix

[kcpoole]

You can add zeolite to a commercial mix to open it up, but not more than about 10 - 20%

I would also ad some crushed granite or Pumice or Scoria if you want to make a blend. Many options depending on what you have available

Ken