Multiple questions - hard pruning and trunk chopping

[Oliver Syd]

Hi All,

I have two main questions for multiple trees!
A few months back I bought some pre bonsai and wondering when I should commence hard pruning and chopping.
They are all rather straight, and I imagine they are originally air layers from big trees, so will need some serious work done to them.
There may be an answer to suit all, Im just finding lots of conflicting information, hence the reach out for help.

Chinese elm
Currently has air layer which has profusely rooted! Good time to chop now, pot and heavy prune?
I have seen multiple thoughts on when to hard prune.... bonsai empire suggest late autumn, my bonsai bible from peter chan says mid summer, and I've read on forums people suggesting spring! Thats one season short of anytime!

Trident maple
Only seeing one visible root on the air layer. Should I wait for autumn or spring to chop and work?

English Oak
Air layer not showing any roots yet, had a little peek and a lot of bulbous looking white calous like stuff going on. Was only a sliver of a peek, so not sure what else is happening around the entire circumference, hopefully its a success. Worth waiting until spring to chop and pot? Assume I have to wait to see plenty of root growth.

Corky bark elm
Shes quite straight and slender but I actually really liked the shape and didnt air layer. I think I may chop her down a bit though and train a new leader to the one I previously chose. Hard pruning timing a mystery to me on this one as with the chinese elm.

Liquid Amber
Also very straight but very thick. Im not entirely sure when this one was potted/possibly air layered. She had quite some movement in the soil so I have assumed she was only recently chopped and potted. because of this I have left her alone and let her grow out to spread that root system. I plan on air layering her for sure, autumn best time to do so with a spring chop?

Lilly Pilly
Air layered a garden tree, seeing some shoots now for a week or two. Wait until autumn to chop and pot?

Lots of questions here, so massive appreciation to anyone giving their thoughts.
Thanks
Oliver

[shibui]

I'll add winter for pruning Chinese elm to round out the year.
You will find that many different growers have their own preferences for working with trees. Rather than suggesting it is a preference they tend to put it as a mandate which can really make it hard for those starting out. You also need to make some allowances for their location and climate. Much of the northern hemisphere is far colder than here so they often have different timings to reflect how the trees respond in cold areas.
Here in Aus I prune most species whenever I have the time and the need and don't believe I have had adverse responses from anything other than maples pruned close to bud burst.
Now is fine to do pruning on Chinese elm, including Corky bark Chinese elm, and you should get quite rapid response.

Trident maple: I have had layers survive with very few roots but it would be far better to wait until it sprouts some more before taking the layer off. I prefer to do heavy pruning on tridents at the beginning of winter but they can still be pruned hard in late spring and summer. New shoots can sometimes be delayed until the following spring if you prune late in autumn. Does not usually kill the tree but can cause some anxiety when no new shoots appear for months.

Some liquidamber can be slow to recover from root pruning. Leave any tree that is showing signs of any weakness alone until it recovers and is healthy.

Lilly Pilly: Remove layers when there is enough roots. Most natives don't grow much in colder weather so we tend to do root pruning and trimming later in spring or summer. if you have enough roots early in autumn it should be OK to cut it off and pot up.

Oak: Not an expert but from the few I do have they seem to only grow in spring. Definitely wait for plenty of roots before taking the layer off.

[Oliver Syd]

Hi Shibui,

Exactly what I was after, thank you very much for the effort! You covered everything!

Really appreciate the time.
Thanks
Oliver