RE: Air layering

Wed, 5 Oct 1994 0:38:16 -0500 (CDT)

Well, I have never air layered a _Nepenthes_ before, but I have done air
layering before. Part c, the toothpick thing, is used for monocots.
This is because they have xylem and phloem bundles scattered thoughout
the stem, while dicots have xylem all along the inside of the stem and
phloem surround the stem, just below the bark. So in a cross-section,
you get rings. Xylem moves water and a few micronutrients up the stem,
while phloem sugars and a few hormones produced in the leaves mainly
down the stem. Auxin is one of those hormones and, among other things,
it is responsible for adventitious root formation, which is what you
want. So in a dicot, you sever the phloem tubes and leave the xylem
tubes in tact so the plant continues to get water. This is why copper
wire works.

What I have found the best way to do this is:

1) Take a razor blade and cut a shallow cut around the place where you
want the cutting to be at (let it keep 3 or four leaves).

2) You make another shallow cut about half an inch to an inch below
that first cut, again girdling the stem.

3) You then make a third shallow cut, vertically this time and connect
the two circular cuts you made earlier. This will allow you to pull
off the phloem and bark all in one rectangular section.

4) Next, get a handful of thoroughly wet, unshredded sphagnum moss and
wrap it around the wound. You will hold this there with some plastic
wrap and then cover the plastic wrap with aluminum foil, shiny side
out. The plastic wrap will hold in the moisture and the foil will
redirect unwanted heat and sunlight from newly forming roots.

This process usually takes about 4 weeks or more. I air layered a
parsimmon (or however you spell it) tree at my girlfriend's house last
March and the clones were not ready until a couple of weeks ago, so it
can also take some time. I do not expect it to take but 4 to 6 weeks.
Just make sure the roots are fairly strong and baby it for a little
while (as if we don't baby the whole lot of them already!). I don't
know how many of these you can make on a vine plant per terminal stem,
but you can keep doing this every few months until you get it whittled
down to the size you want. Also, I wanted to mention that air layering
is done, for outdoor plants, in the spring when the bark is loose and
slipping. For a greenhouse or indoor plant, I don't think that this is
terribly important as the bark will always be slipping, but someone else
can chime in if I am not quite right on this point. Good luck.

Matthew Thompson
Texas A&M University