Air-layer deformity

[emk]

This was my big year to try out air layering for the first time on an assortment of trees that I was planning to trunk-chop or just use for ornamental trees/shrubs around the yard. I got the layers started in May and used the "1-inch ring-bark (without bridge), apply rooting hormone powder, wrap with ball of wet sphagnum, cover with plastic, and wrap in black plastic" method.

I was excited to see that my Dawn Redwood was the first to show signs of rooting out. In a misguided fit of impatience I detached this layer from the host tree in late August (thankfully I had another layer going further down the trunk) to find that, in fact, I did not have any roots...just some odd swollen lumps. I tried to pot it up anyways, but it didn't make it (that whole not-having-roots thing).

Well, now it's getting to be the chilly side of November and I decided to take a close look at what was going on with my other layers. The other layer on the Dawn Redwood is going great - real roots this time. The Crab Apple is also doing well. The white pine was just refusing to respond at all - the moss just fell right off the trunk since there were no roots holding it in place.

But the oddest thing was my Linden tree - it seems to have reacted the same way as my first Dawn Redwood layer...but only on one side, and on the linden this swelling was huge.

So...what's thing kind of growth called? What causes this? What am I doing wrong? How can I avoid this in the future?

I was under the impression that air-layering was the sure-fired way to get a perfectly radial root flare...this certainly wasn't what I was expecting.

 

[bonhe]

Hi Emk, it shows a callous. It happens a lot with Ume when we try to make a cutting. My teacher told me that one should remove a callous, then reput it into the soil. Last year, I airlayed the quince, after 6 weeks, I found a callous same as yours, without a root at all. I didn't remove a callous, and just seperated it from its mom, and put it into the good drainage soil. Up to this time, it 's still alive. Bonhe

 

[Tachigi]

EMK,
First of don't put off by this, its part of the learning curve. As Bohne said its a callous. The probable reason that it formed is that when you banded the tree for layer you didn't go deep enough leaving cambium on the trunk. As trees do, it tried to heal itself and was able to because of the cambium bridge between the lower and upper section.

So in this case, you'll have to wait till next spring to give it a go again. Next time around after making your band try these additional steps to help yourself with a successful air-layer. Drag the edge of your knife lightly,but firmly, over the banded area. This will scrape the surface removing any remaining cambium that still maybe present. Also don't rush to wrap the layer into rooting medium a little air dry time will help kill any cambium that you missed. Finally I have found alcohol applied with a Q-Tip over the layer band cinches the deal by killing off the cambium it touches and also sterilizes the wound.

Congrats on making your first attempt at layering and the success you had on some.

 

[emk]

Thanks much guys. Yeah, I might have been too "gentle" when removing the bark. I thought I'd taken all the green cambium material off, but some of the methods you recommend might help make sure next time.

 

[M.B.]

Hey EMK, I also tried some air layers this summer and had trouble with a couple. One was a Seiju elm that also calloused instead of growing roots. I took a bit of wood from the middle of the cut so it shouldn't have grown back, but it did. One of the older members in the local bonsai club said I probably did two things wrong. The first thing is I kept the airlayer too wet. It was unintended but because of where the layer was, it got water going into the plastic wrapping from overhead watering. The second thing he said I probably packed the sphagnum moss way too tight and coupled with the water dripping into the plastic almost every day, it might have rotted any roots that tried to grow. He said he didn't have good luck with layers that stayed too wet. He actually puts the damp moss around the trunk and once secured, doesn't usually water again until he's ready to separate the layer.
I'll try again next year but will try the pot with soil method since I need better drainage in that spot.
Mary B.

 

[milehigh_7]

EMK,
First of don't put off by this, its part of the learning curve. As Bohne said its a callous. The probable reason that it formed is that when you banded the tree for layer you didn't go deep enough leaving cambium on the trunk. As trees do, it tried to heal itself and was able to because of the cambium bridge between the lower and upper section.

So in this case, you'll have to wait till next spring to give it a go again. Next time around after making your band try these additional steps to help yourself with a successful air-layer. Drag the edge of your knife lightly,but firmly, over the banded area. This will scrape the surface removing any remaining cambium that still maybe present. Also don't rush to wrap the layer into rooting medium a little air dry time will help kill any cambium that you missed. Finally I have found alcohol applied with a Q-Tip over the layer band cinches the deal by killing off the cambium it touches and also sterilizes the wound.

Congrats on making your first attempt at layering and the success you had on some.

Tom thanks for this valuable bit of info!

 

[Smoke]

Anyone wish to venture a guess why it did not make roots? I mean we know why by looking at it but I'm talking the science......

 

[bougie nights]

EMK-
I did the same thing last year with a hackberry and it healed itself with callous tissue. I was too gentle as well.
But looking at your tree, it looks like the callous bulge creates a nice flare at the top of it. That could be an excellent base for the tree if you try again.

 

[emk]

EMK-
I did the same thing last year with a hackberry and it healed itself with callous tissue. I was too gentle as well.
But looking at your tree, it looks like the callous bulge creates a nice flare at the top of it. That could be an excellent base for the tree if you try again.

I got impatient and trunk-chopped this tree a few weeks back. I figure I can always air-layer a sacrifice branch or somesuch in the future.