treebeard55

You'll notice in the 2nd picture that the girdling cut is made at a slant. That's to enable me to flip the tree back to the left, and plant it as a semi-cascade again, once the upper part has been separated. Here's a quick-and-dirty virt of the idea.

By the way, Phil or Jim, should these updates be in their own thread, rather than attached to the "sticky poll?"

Attached Images

B092 2011-4-14, virt 1.jpg (85.3 KB, 7 views)

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Treebeard 55
Steve Moore
http://hoosierbonsai.blogspot.com

The most important bonsai tool is your brain.

treebeard55

Learning from a loss.

As some of you may have noted, I performed the airlayer on this tree in mid-April, as the new foliage was just developing. I picked that time on the advice of some others who have more experience with yews.

The tree did fine until mid-summer, when the foliage began to wilt, a little at a time. I moved it into more shade, misted it frequently, treated it with fungicide, even replaced the sphagnum around the air-layer site. Nothing helped. Within six weeks the entire tree was dead. An autopsy showed that a little bit of callous had developed at the air-layer point, but not nearly enough to produce new roots.

I was at a loss to explain why the tree had died, until I had a chance to ask Ryan Neill about it at the Mid-America Show in August. What he told me cleared up the mystery.

First, he said, the timing couldn't have been much worse! When a tree breaks dormancy in the spring, it relies heavily on the food products that were stored in the roots the summer before, to fuel that hard spring push. (A deciduous tree relies entirely on those reserves, at first.) As those reserves are used up, the new foliage is developing; and by the time the previous year's stores are exhausted, the leaves/needles are ready to take over completely the job of supplying the entire tree with sugars and other photosynthates.

The plant then proceeds to replace the reserves with fresh stores for the next spring; and then it starts producing a surplus to support further summer growth.

The time to perform an air-layer on a temperate-zone tree, Ryan, explained, is after the tree has had a chance to replenish its reserves and start building a surplus. That way, the original roots have a food supply to keep them going while the air-layer's roots develop. Signs that the plant is ready, Ryan said, are that all the spring growth has matured, and now side/adventitious buds are beginning to swell for a second, lesser flush of growth.

By doing my air-layer when I did, I cut the tree's roots off from any resupply from the foliage. Once the previous year's reserves were used up, the roots began to starve, and they starved before new roots could develop at the air-layer point. With the roots dead, the rest of the tree died quickly as well.

There was a second mistake I made as well, Ryan Neill told me. An air-layer on a conifer should never be made below all the foliage. In such cases, in his observation and experience, the failure rate is 100%!

__________________
Treebeard 55
Steve Moore
http://hoosierbonsai.blogspot.com

The most important bonsai tool is your brain.