In the past I've successfully transplanted these from October through to January. They don't even seem to mind being transplanted in quite hot weather. Daytime max temps have been in the mid-high 30sC this week. Attempts to transplant banksias in autumn and winter have been unsuccessful.
A couple of years ago I trialed a number of different timings - dig and cut in one operation; cut a few weeks before then dig when new shoots start growing; dig without pruning. All of these gave similar survival and growth rates.
At 2 m tall these were a little too big to dig without pruning so, as you can see, I cut them back a few weeks ago in preparation for transplant.
It took a bit of work with shovel and crowbar to get this one out on the ground but fortunately banksia roots are relatively brittle so I don't need to dig right under the trunk, just dig down the sides and wobble it until remaining vertical roots snap. I don't try to keep the soil intact when I transplant trees. When I dig I generally shake and poke the rootball to dislodge as much garden soil as will fall away easily.
Next comes root pruning. I know a few of you will be horrified at how much I've reduced these roots. This is, in fact, the hardest I've ever reduced banksia roots when transplanting. The trunk is not particularly attractive so I decided to use this one as a test subject. After initial root pruning the root ball was just a little larger than a 30 cm orchid pot so I either needed to find a larger pot or reduce the roots just a bit more..... Apologies for the orientation. Ausbonsai upload appears to rotate pics back to the original orientation.
If you can tear your eyes away from the butchered roots you can see the new shoots resulting from the hard prune a few weeks ago. Banksias respond really well to hard pruning and produce lots of new buds, even on older, bare wood so don't be frightened to cut banksias. Note those shoots are all clustered near the ends of remaining trunk and branches. Probably would have been better to cut this trunk a little lower. There's not a lot of room but I did get some mix around those remaining roots. Because it is still pretty tall I had to tie it into the pot so it won't fall over.
Watered in well then into the recovery spot - under a bench this year. Still plenty of light but out of direct sun for most of the day. They'll get watered with the rest of the trees twice each day -early morning and evening.
That's the 3rd transplant so far and there's still a couple to go.
and see how they go.
