I’m new to air layering, and have a question about using polyethylene film to wrap around sphagnum moss and create a seal that, in theory, will leave the air layer easier to maintain, without the need for water monitoring.
First thing: I’ve looked everywhere I can think of to try and get guidance on the film itself. Is there a certain thickness/brand/form of PE file that seems to work correctly? Even watching videos, it seems like everyone’s film is more or less flimsy/thick/“clingy”/etc. than the one before it. Is it a bag? Is it a roll of film? Is it the thicker sheets that are used on greenhouses? Does it matter as long as it’s sealed correctly? It seems that plastic sheets are measured by thickness in “mil”s. I believe that a mil is a thousandth of an inch.
Lastly: What are the benefits, if any, of not completely sealing the damp moss and letting rain get in, while poking holes for it to drain. For a beginner’s first batch of attempts, would it be easier or more reliable to seal it tight and hope that the moss’s moisture stays in while not drowning the plant, or drying out the moss?
Thanks for any help! I really appreciate your time.
I generally use a ziplock style bag for food storage - readily available from the kitchen and a reasonable thickness with which to work. I have covered some of them with aluminum foil to so they are darker inside.
I also like to leave it open at the top and poke a couple of low holes. I water the airlayer when I water the tree.
Have you watched the stream by David Cutchins? He does air layers at a commercial nursery and uses techniques that work and make money!
I cannot paste the link but if you look up propagation on Air Layer Primer it will take you to the stream. Not sure why his links are not able to be forwarded. 0_0
As far as the film used…many videos I have seen, Ryan included, I believe reuse akadama bags, or other landscape supply bags (pumice,lava,sand,bark,etc.). They are typically thick and the recycle aspect is nice, plus you are likely to have them on hand… I have used and had success with foil, ziplock, and black trash bags as well, but find I prefer the clear just because I can see roots and dampness, foil however is super simple.
A word of caution to a beginner, and I am no pro, far far from it…sphagnum stays wet and holds water well especially if you seal both ends off pretty tightly or use foil. Foil is the preferred method of David Cutchin from the above video.
Thanks for the help! In my case, the first few I plan on trying are on huge trees. So I haven’t ever watered them…but I could always check on the moss when I’m watering my other plants.
Thanks for the heads up moon! I’ve always read that the moss should be “damp, but not wet”…so I’m thinking I squeeze out enough water that it doesn’t drip anymore, but is still holding a decent amount of moisture. Is that even close to what damp is when dealing with sealed-off sphagnum?
You’ve been getting some good pointers. Let me just chime in with 3 points:
You don’t want to seal the plastic completely (this bears repeating) or you’ll obstruct the entrance of oxygen-bearing air.
Polyethylene plastic sheeting sold for house painter’s drop cloths works fine and is inexpensive. I always by the thinnest I can find.
A veterinary syringe, available in most farm stores, works great for re-hydrating the sphag when it starts to dry out. Just be sure to cap the needle afterward.