Hey Jonas. I have a question for you. I have a trident maple that I want to air layer. It is a straight (vertical) tree with a few branches that is about 7 foot tall with a 1-1/2” trunk at the base. How many air layers can I do at one time?
The safest approach is to do one at a time starting with the top, but it’s possible to do more than one if there are plenty of branches between layers. I’ve done this with cryptomeria but not trident maples so I don’t know if the species is better - or worse - suited to the multi-approach.
What I found when I did two at once was that the lack of branches between layers led to few roots on the lower layer. I’d only try this if there were lots of branches radiating all around the trunk between each layer and if I were OK taking a chance that it might not work.