Airlayering Lilac

I have an old, old lilac bush in my landscape that I would like to bonsai. It has a 3 inch trunk with very flaky, aged bark. The problem is that there is reverse taper from the ground up to about 6 inches high. After that, it begins to taper back the correct way. I'm wondering if it is possible to airlayer this at the point where it begins to taper back down. I've looked up airlayer lilacs a little bit online, but the only references I've found where done on younger wood/smaller branches. Also these cuttings were not for bonsai of course. Could this work on such old wood for my purposes?

The ability to make adventitious roots generally declines with the plant's age. It also declines with ontological age which means that it is harder for an air-layer succeed the farther it is away from the ground level.

In summary, if it can be done (which it likely can), you've got the best situation: on the trunk near the ground. Bear in mind that sugars and auxins from the leaves above the girdle are what drive the formation of adventitious roots in an air-layer. Nothing will happen during the winter.

If you are using a soil like turface, you can simply make a wire stricture just below where you want the new base of the tree to be and just raise the soil level to cover it. You will likely get additional basal flare and, within a year or two, a new set of roots emerging from just above the stricture (see bonsai4me).

Doing the conventional girdling of the tree will likely get you new roots by the end of next season.

And finally, as far as air-layering is concerned, lilac is just another tree - there's nothing special about it.

You might also want to take a look at Walter Pall's lilacs. There six at this site http://walter-pall.de/b02gallery_non_conifers.jpg.dir/index.html Good luck.

Thank you for your comments. Yes, I have seen walter's pictyres pictures. They re amazing! i visit his blog as often as I can. That is what inspired me to try with this tree. That, and the irresistible urge to find the bonsai in every tree, shrub, bush, sapling and seedling in sight...