The message
from (Nick Maclaren) contains these words:
In article ,
Jaques d'Alltrades writes:
| The message
| from "Arthur" contains these words:
|
| But the roots will keep growing ...
|
| No they won't, not if you keep the tree trimmed. They have no
need to.
|
| Not so. Even trees that have been regularly pollarded will grow
massive
| root structures over the years. The trunk increases in girth
every year,
| and so do the roots supporting it.
|
| We were talking of coppicing not polling. Root growth expands to match
| needs above ground.

It's not quite that simple. The roots of coppiced plants do keep
growing, though not usually as fast, because the plant has to put
more energy into regrowing the shoots. You can see that on old
ones, including Cornus (which is often grown that way).

True, up to a point - it depends how you coppice. If you rotate a third
a year the roots should stabilise very quickly.

If you coppice once every three/etc years, the roots will still
stabilise somewhere, though maybe at a greater bulk.

Actually, if a pollard tree is trimmed regularly, the roots on that will
stabilise. The thickness of the trunk is almost immaterial, as the
living tissue on that is more-or less restricted to the bast and the
cambium. It's the new growth from the polled part which requires fed.
Restrict it and you restrict the need for outward root growth.

--
Rusty Hinge http://www.users.zetnet.co.uk/hi-fi/tqt.htm

Dark thoughts about the Wumpus concerto played with piano,
iron bar and two sledge hammers. (Wumpus, 15/11/03)