look for threads on layering in bonsai groups. They have a lot of info about air layering & ground layer. I think it is worth joining so that you can see the pictures

Keith

Here is a link that might be useful: bonsai nut propagation forum

Our native Vine Maple roots when a limb or trunk is on the ground for some time. Propagation of palmatums is usually done by seeds or named varieties by grafting.
Mike

Air layering has been very successful for me with japanese maples, but I've only tried it with young trees that grew from seed. The only problem is that particularly heavily bred varieties can have weaker root systems than seedling stock. This, along with speed of propagation, is one of the reasons so many named varieties are grafted. I think it's definitely worth a shot, and I've often fantasized about sneaking into arboretums at night to air layer their maple collections.

Maples air layer easily. As a bonsai practitioner (and bonsai judge), I realize it's imperative that my trees exhibit a strong buttress, and that the roots radiate evenly and horizontally around the tree. When buying deciduous material, experienced bonsai artists look almost exclusively at the root structure (nebari) where the plant makes the transition from root to trunk when deciding if the plant they are considering is one they would like to own. Here is how I develop good roots by air layering.

This is a trident maple that has been air layered:
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This one was done using a wire to constrict the polar flow of photosynthate and auxin, so they collect in tissue above the constriction and create a bulge that adds to the root buttress:
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These pictures are actually the first repot after the air layer was completed, but the constriction wire is very visible.

These plants were layered using soil in a pot that was arranged around the constriction. The BEST way to ensure success is like this:

A) Choose the branch or stem to be layered and wrap 1 or 2 zip ties around the branch.
{{gwi:10877}}
This is a hornbeam - maples are even easier.

Wait for a considerable bulge to develop above the constriction (I didn't on this tree), then drill a few holes that are evenly spaced, just above the constriction. Fill the holes with rooting gel, let the gel dry,
{{gwi:10879}}

then, start your layer. Here is a zelcova in a container (on right) I'm layering the top off of in a pot:
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It's also very helpful if you precondition the area above the constriction by keeping light away from that area. That predisposes the plant to developing root initials in that area. I use electrical tape applied not too tightly and applied so the sticky part is facing out - away from the bark. Now is a good time to begin preparing for an air layer you intend to start next spring. You can also use the method by which you ring the bark and remove a ring equal to at least 1.5x the diameter of the trunk @ the point at which you ring it. Be sure you remove ALL of the cambium, right down to sapwood.

{{gwi:92885}}

Al

When you are explaining how to drill the holes etc. and then you say to start the layering, do you mean adding a pot with soil or peat and then wrapping it? I understand what you are saying to do up to that point.
Thanks,
Tam

Scroll up 2 pictures and note the hornbeam layer in progress. I split the plastic pot, then prepared a layer as shown a little upthread, using zip ties and 1/8 inch holes drilled down to the phloem and treated with rooting gel. The layer is 2/3 - 3/4 of the way down from the top of the plastic pot, so new roots can't dry out while they're forming.

You can also use sphagnum moss (not peat)
{{gwi:10366}}

wrapped around a branch layer, sealed with plastic, and covered with aluminum foil to prevent over-heating due to solar gain. Check the moss periodically & use a syringe & needle to inject water through the plastic if it's needed. This method requires that you ring the bark all the way down to the phloem tissue. The length of the bark removed should be 1-1/2 - 2X the thickness of the branch being layered.

Al

Thank you for the detailed information. I cut the bark and cambium layers off of a dwarf Japanese Maple, painted it with Clonex, put a pot on it and filled it with 1/2 soil and 1/2 with a type of water soil medium (similar to those added to soil to retain moisture) then wired the pot to a normal shape and added clear plastic wrap and aluminum foil. I did not drill holes or do any wiring to the branch. Do you think what I did will be sufficient or should I go back and drill the holes or do anything else? I tried air layering like this before without using a rooting hormone or pot but they failed, so I am concerned about these failing. The branch is about 3 1/2 to 4" around. I stripped everything for about 8" above the area that I cut and I pruned the top.
Thanks,
Tam

Ringing the tree (stripping the bark) does the same things that the tourniquet does - causes a cessation of the polar flow of auxin and causes auxin and carbohydrates to build up in the tissues immediately above the cut, both of which promote root formation, so you should be just fine.

Good luck!!

Al

Thank you so much. I have one more question. I tried the same technique on a dwarf Pocomoke Crape Myrtle but there was no end to the cambium layer, it was green all the way through I suspect so I stopped and just painted it with the Clonex and wrapped it with a soil and water pellet mix. Is it possible to air layer like this when you don't reach wood? I really want some cuttings off of this 16" tall and 44" wide bush and cuttings don't seem to work. Any input at all would be so appreciated!!!
Tam

Crepe myrtles come easily from root cuttings. Dig the cuttings in early spring and pot up or plant out in beds with loose soil.

If you want to do cuttings, hard or softwood cuttings taken in spring or summer (take them from right where they join the main branch, from the south side of the plant). Use 6-8 inch cuttings with about 3-4 nodes per cutting. Remove all the leaves except the last two or three & bury the cutting almost to the base of the lowest leaf.

You need a very well-aerated medium for cuttings. If you stick them in MG soil and the base of the cutting is below the level of saturated soil at the bottom of the container, expect failure due to a lack of O2 to the cutting.

Shallow pots are most difficult to grow in because a heavy soil might be 100% saturated in them, yet the maple above and this one
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do just fine in this soil
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which is what I start cuttings in, too.

Al

I have seen videos where, it looks like they used cat litter as a soil medium. I realize that if using cat liter, it should be of the plain generic type with the least amount of additives, but can the litter be used as maybe a 50% soil additive for cost savings

Cat litter used in container media should remain structurally stable after being frozen in water over-night, and should be free of perfumes, dyes, and clumping agents. It should also be screened for use in the gritty mix, and avoided or screened for use in bark-based media if it has a significant fraction of fines.

Al

I've also been told that Napa auto products has a spill clean up mixture that is good. do you know about this product?

NAPA's part #8822 is calcined (fired at high temps) diatomaceous earth, and is usually appropriate as a fraction of container media. Because of what it's used for, it's not particularly important if this product retains it's structural stability through freeze/thaw cycles. so it should be tested for stability by freezing some of the coarse particles in a plastic cup filled with enough water to cover the material. If it is still stable after it thaws, it's appropriate for use in container media.

Al

There is also OptiSorb from FastenAll. Same as 8822 I think the particle size is larger than that of the 8822 and Turface.