Maple Air-layer

Back in June, I decided that I would attempt my first air-layer. This technique is much like taking a cutting except the part being layered is left on the tree untill sufficient roots have formed. At this point the branch is then removed and potted up by itself. I had a largish japanese maple which I had been allowing to grow freely for a couple of years. I decided that I would like to shorten this tree before it began bonsai training, but rather than just cutting the top off, I would air-layer it and get two trees for the price of one.

The spot on the trunk was selected and a ring of bark was removed from around the trunk at this point.









I carefully removed all of the "pithy" wood from the area which is the cambium layer of the bark which transports food within the plant. If all of the cambium is not taken off then there is a chance the area could just heal back over and the layer would fail. I have seen people suggest that leaving a "bridge" of cambium across the area might help, but I think this would just increase the chance of it failing. I applied a small amount of rooting hormone to the top edge of the layer and then prepared the sphagnum moss which would be used to cover the air-layer and facilitate a healthy rooting environment. This was done by simply soaking it in a bucket of water for a short while.


Clumps of the sphagnum moss were then taken out of the water and rung out to remove excess water and leave them moist. These clumps were then arranged around the prepared area and held in place with plastic wrap.


A final layer of black plastic was used to cover the clear plastic wrap, this was to reduce the amount of light getting to the new roots and hopefully help them to grow. I would need to check on the layer frequently to ensure it did not dry out, I could provide it with moisture via a syringe and a small hole in the plastic covering.

The layer has now been on for 4 months and on inspection I am unsure whether there has been much root growth. Unwilling to disturb it I will provide it with some Winter protection in the form of some garden fleece, and leave it on over the Winter to inspect it again in the Spring.