On Mon, 1 Jun 2009 20:01:54 +0100
"Nicholas" wrote:

This is the problem.
An ash tree growing tight alongside the buttress of an old building.
The trunk is about 10" dia.
We have cut the tree down, and limbs off, as far as possible in the hope
that it would gracefully die.
It still makes very robust shoots and this is the 6th season of our trying
to be rid of it.
The current plot is to drill holes in the trunk and insert poison of some
kind.
I am normally against anything of this kind but the tree has to go.
Any suggestions please on what poison might be effective?

The problem will be growth from dormant buds in the cambium layer,
between the bark and the heartwood. The heartwood is already
dead. Putting brushwood-killer into the deep holes round the edge
of the heartwood might work, but only as it leaches into the cambium
layer. You have a live tree with lots of roots and trunk - albeit not a
tall one.

I suggest that you debark as much of the remaining trunk as possible,
this removes the dormant bugs. It also gives the fungi lots of ways
in.

There is a story that says that copper nails will kill a tree, but I've
no idea how long, or how many, it takes.

I have an 2 foot ash stump on my boundary that was alive and spouting
when we moved here four years ago, I used the 'strip bark' method on
it's own and it is now dead. I believe it was felled about three years
before we arrived (the full live tree is still on Google Earth!). So
it's about the same age as yours.

R.