When TFN Editor Bob Cannon came to our Bal Harbour grove last year to put on a few airlayers, there was nothing unusual afoot: at first. When he commenced stuffing clear plastic bags with sphagnum moss I wondered, 'What is going on?' I assumed he lacked the usual finger dexterity to be able to hold dampened moss around the girdled limb without dropping most of it on the ground. I was only mildly interested, feeling Bob was using the moss-filled plastic bags as a ploy until he mastered the more normal methods of producing airlayers.
After some of his marcots were completed I had a chance to inspect the results. I found each presented a symmetrical round ball without any of the sphagnum protruding from underneath the layer, as it frequently does, forming a wick and drying out the rootball. Curious, I decided to experiment with this unique approach myself. I put six marcots on our 'Emperor' lychee (Litchi chinensis).
It was amazing how quickly and effortlessly these were attached to the girdled branches. With all the moss located inside the plastic bag, there was nothing to fall out. To enable the future emerging roots to enter the bag and penetrate the enclosed moss, a centered crosscut was made halfway through the bag. This was now wrapped around the girdled part of the branch and tied (I tied 8"-long grafting strips).
Bob uses several refinements. He pre-wets his moss in a water solution containing soluble fertilizer and a rooting hormone. Our RFCI Editor first got the idea of stuffing bags with sphagnum from the late Morris Arkin of carambola (Averrhoa carambola) fame. By varying the dimensions of the plastic bags, marcots from the size of a golf ball to a pumpkin can easily be made. Heavy aluminium foil is usually put around the completed airlayer to exclude the light and offer extra protection.
Most marcots require up to three months to fully root out. If this system was such a winner for me I'm sure it will do the same for you. Why not give it a try?
DATE: November 1997
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