I started an airlayer on 2 trident maples earlier this year. When I went to separate them 2 weekends ago I found that one had calloused over. I'll try to find the before pictures, but here it is after I cleaned it up and started the layer again.
(This tree will be pampered in a greenhouse after it loses its leaves to keep whatever gets growing before fall from dying.)
Was the other one a similar size, and did it have any old scars in the layer area..... any pics before you seperated the other one.
I've not done air-layering before, but have done my first on a Japanese Maple about a month ago. Hoping for a good result.
My guess , this one possibly dried out..... spaghnum moss wasn't kept moist enough.
How long before you unwrapped it?