This is an elm branch that I tried to airlayer last spring, spring 2017. Not actually sure which species. Maybe I scraped too much of the xylem off, but while I was removing the bark I noticed some rot on one side of it. Basically the air layer was on for only a month and a half when a windstorm broke the branch off of the tree completely! I was not super psyched about this obviously. When I opened up the plastic and sorted through the moss I found NO ROOTS had formed whatsoever. All I could find were two minuscule nubs that were the start of roots, each of these was about the size of of the head of a pin. The logical thing to do was to toss the branch on the compost pile.
But I had a hunch, I decided to take the branch home, saw off the bulk of it (to make the chop for the appropriate size) stick it in a nursery pot with %100 perlite and then put the tree and pot into a black garbage bag and tie the garbage bag shut. I then put the tree-in-garbage-bag into full sun. This was around the first week of June.
This is a technique i’ve used with collected hawthorns to force dormant buds to pop and to get explosive root growth. Horticulturalist call it “sweating”. Tony Tickle uses this for collecting hawthorn. The idea behind sealing a tree inside a black bag and putting into full sun is that the intense heat and %100 humidity forces the tree into root and shoot overdive. You will often find that roots start growing out of the trunk way above the soil line.
I basically turned this failed airlayer into a giant cutting, it’s about 3 inches across at the base. Unfortunately I didn’t take any pics before I potted it up.
View attachment 208339
“Aerial” roots forming above the soil...
View attachment 208340
View attachment 208341
And here comes the foliage...
View attachment 208342
View attachment 208343
From this happy accident and incidental experiment, I am convinced it is possible to take very large elm cuttings, something like 6 inches across or maybe more, if it is done at the right time of year and the black bag sweating technique is applied. I will be performing some more experiments to see how far I can push this next spring. I will try to find a large elm branch, saw it off, and apply this same technique to see how it reacts
.
View attachment 208339View attachment 208340View attachment 208341View attachment 208342View attachment 208343