I’m new here. Looks like not a lot of people are getting answers to air layering questions in the last year or two.
I’ve only done one, on a Japanese maple, but it was really successful. I’ll try to explain the details.
In fall of 2021, I got two palmatums on clearance for like $20 each at the depot or a similar store. Score! But they had long, branchless trunks, and then lots of branches higher up. Not ideal. So I did an experiment. I trunk chopped one, the one with the better nebari, in the winter to like 5” tall and I figured it would sprout like crazy in the spring. Nope. It’s still green and chilling there as of AUGUST but no leafing out. It’s probably gonna die but I'll leave it to next spring, who knows.
The other one, I trimmed back pretty hard but then let it bud out in the spring, and there was tons of new growth - just none down on the trunk. Around mid June or something there was a new sprout like 2/3 up the trunk - not low enough for me to trunk chop and be happy with, but now if I air layered above that new growth, I could disattach the top of the tree and probably the bottom would live with that set of growth.
I did the knife-cutting and root-hormone (I used a gel one from Amazon), wrapped in wet sphagnum moss and Saran Wrap. I used some copper wire to hold it in place, and made a kind of funnel in the Saran so if I was watering from above, or if it rained, it would soak the sphagnum moss too.
It was only like 4-5 weeks before I checked it and there were tons of roots. So I chopped, potted the rooted cutting in diatomaceous earth (6622), with the sphagnum moss and everything, and wired it down so it didn’t move too much. It’s been a month or two now and it’s doing well! Doesn’t look show worthy or anything but I’ve got a pretty thick trunk and the base has budded back lower too!
I’ll try to track down some photos and update later.
BTW I’m in Pennsylvania, 6a/7b
