During my first year in Bonsai I bought a dwarf variety Japanese maple for several hundred dollars from a local landscape nursery. After reading a couple Bonsai Today articles on Air Layering I thought to myself, "well... how difficult could this really be?" When I brought the tree home, I cut all the branches back really hard and used my knife to ring bark a couple inches in width right above the graft. I used rooting hormone on the top section of ring barked area and a plastic bag to hold the mix of Turface, bark and crushed granite in place. Over the next several months the trees health slowly declined until it eventually died. Of course this was very upsetting to me at the time, but it also helped engrain some very valuable lessons into my brain so I could learn from my mistakes. Currently I still believe that successful air layer is a very valuable skill for Bonsai enthusiasts to become proficient in. When done successfully it gives us the best chance for creating beautiful future nebari.
Pictured below are the results from two air layers that I removed last week. I have a long way to go in order to consider myself as confident as I’d like when Air Layering. For now I plan to practice a lot and experiment with different methods. Here are a couple different things I tried last year.
This was done by girdling completely around the branch and applying rooting hormone to the area just above where the bark, cambium, and phloem was removed in winter 2013. I cut up long fiber New Zealand sphagnum moss and pre-moistened it before applying around the layer. By pre-moistening the moss, the rooting hormone is not washed away during the first watering and allowed to remain in contact with the branch for longer.
I left the layer on for one year and removed it last week. I allowed the moss to dry between waterings, but never to the point of being bone dry. One of the advantages to using a clear plastic bag is that it becomes easy to tell when the layer has produced a sufficient amount of roots.
Here are the results after combing out the roots and untangling them from the moss. This is as far as I took things for the initial potting. I left some moss still embedded in the roots so I did not tear away too many roots when combing them out.
This is my double trunk flowering plum all potted up for now. I plan to grow this tree out for several years and trunk chop in the future to produce more taper and movement.
Above is the result from using a colander filled with akadama, pumice and lava on my Lemon tree. While the leaves and fruit are likely too big for Bonsai, I'm considering growing out the trunk and then grafting a dwarf citrus to create the branching many years from now. I applied this air layer by using a standard ring bark, rooting hormone and pre moistened soil in Feb 2013.
Using the colander required slightly more frequent watering’s but produced good results. Using this container, the roots were naturally air pruned which likely produced more roots and roots that were less tangled from circling around the inside of a container.
These roots were easier than the plumb to comb out because the roots of lemon trees are thicker, stronger and they were not as tangled.
I used my root cutter to remove the bottom section of the branch right up to where the first roots came out from the trunk.
I washed the remaining soil out with a hose and removed roots growing above where the first section of the roots protrudes from the trunk. I potted the tree up and will continue to work on the roots during each future repotting.