Air Layering and Trunk Chopping in Zone 7b

What time of year can air layering and trunk chopping be done on a Japanese Maple in zone 7b? I have read a lot of information on these techniques, but the writers are not in my zone. Thanks for your help. h

I have always done chops in early spring. I have not air layered anything yet.

Spring is always the best time, if only because it gives you time to get a decent crop of roots before you separate the layer in the fall. In 7b (about where I am) your layer won't be ready in the fall and you'll need to give it a LOT of protection over winter.

I've seen a few air layer pictures here and elsewhere that -- to my mind -- don't have anywhere near enough roots to support the separated layer. The plastic or pot should be jam-filled with roots before separation.

Thanks to you both. I have another question about winter protection. At what temperature do they need protection? Most of mine are very young and are in 14 inch square grow boxes. I have seen pictures of bonsai just covered in snow with no protection at all. Yet, I read about putting them in a greenhouse or garage for the winter. I am just confused.

I agree with Jim...Spring wlll be a better time to air layer Japanese Maples, which can be done quite easily. I have several Japanese Maples here in SC (7b-8 ) and I usually leave them out all Winter, on the ground with a bit of mulch on the pots. If it does drop into the teens F, I may bring them into the unheated garage for a night or two.

Thanks, Jim. That tells me what I need to know.