Mid winter bonsai work on natives

[MattM]

Hello all,
Just curious what if any work are you doing on your Australian natives at this time of the year?
I get a bit confused as to what I should be doing mid winter. I mainly have banksias, with a few tea trees and kunzea.
I am in Western Sydney.
Thanks,
Matt

[GavinG]

In frosty Canberra, it's an established principle that you leave your natives with a good head of hair over winter - I killed one Lepto by pruning too hard too late. What's too late? I trimmed a Kunzea back quite tightly for the NBPCA Bonsai Reshaped shohin display in April, and lost the end of a branch when the frosts hit. If you are in the Hawkesbury, you won't be immune to frosts.

So. Don't hack hard. But you can wire, devise and plot. Certainly no repots at this time (in Canberra) but it's a good time to line pots up and ponder. Repotting season is often so busy that decisions can sometimes be too hasty - grab what's nearest that "will do". Plotting also gives you time to go pot-plundering, mail-ordering and the like.

So it's think time. Coffee, tea, red wine have all been recommended.

Gavin

[Rory]

Thats a very interesting question and can be different depending on location, and species, just as Gavin has said.

Banksia: Depends on the Banksia
Leptospermum: Depends on the Letpo
Kunzea: Not a huge amount of experience with these, as I only have worked a lot with 2

BANKSIA:
Most of them are highly vulnerable to root rot. Whenever you do rootwork on a tree in a pot, it sets back the roots, and thus heavily slows down the uptake of water. This is the absolute worst thing to have happen over winter with Banksia. The only reason you would do this now is if there is a serious problem with the roots and you need to remove already visible rootrot or some other reason.
You want to wait until Banksia are really pushing out growth fast before you do anything. Styling and shaping is fine now, but I wouldn't be cutting anything back at the moment. Too many times I've cut off a branch in winter with banksia, and had them dieback a lot, (its not a given, but not worth risking)

Leptospermum: Some species of Lepto actually are fine with repotting now as they are strongly pushing out growth in mid winter. I would have no issues repotting a brachyandrum or a madidum now for example. Many of my torulosa casuarina are just pouring out new growth and I wouldn't flinch at working the roots, as they would have no problem with it now.

Essentially the best overall advice is to work the tree only if its growing strongly. I have many natives that are absolutely powering on at the moment in the dead of winter, and I would have no issues repotting them and cutting back roots right now. But if you do, don't have it in a slow draining mix and don't have the roots over-potted afterwards (i.e. the roots sitting in a large mix that they wont be pulling the water up quickly enough to maintain good health).