Tonight at the club night, one of our club members Tony Oswin did a demonstration on how to air layer a Trident maple and started by selecting the branches to be air layered. The raw material belongs to Andy and he had tried previously to set air layers but unsuccessfully.
Tony proceeded to use a sharp Stanley knife to cut through the bark and into the cambium layer and worked to scrape off all the cambium layer down to the heartwood in a concentric ring around the same diameter as the branch being air layered.
He then tied a clear plastic sheet around the branch bottom and secured it in place with a plastic zip tie his preference. He then packed the plastic with wet sphagnum moss and made the plastic sheet into a cup shape to hold the moss evenly around the cut section on the trunk making sure it was tightly packed to make contact with the exposed wood.
He then used a second cable tie to secure the top of the clear plastic sheet before applying a second plastic sheet but this time a black one. He secured the base of this one with a zip tie and the top with a small piece of wire so it would be easily undone to check on the progress of the root development in the sphagnum moss each time. He recommends checking the moss to ensure it remains moist and watering it as necessary. He suggests it can take up to 6 months on Maples and longer on some species like Blackthorn.
During the demonstration club members asked questions and had a general discussion about species and air layering successes.