"John H Wood" wrote in message
...
Can anyone explain why ring barking a tree will usually eventually
kill it, but cutting the stem either at head height as in pollarding
or at ground level as in coppicing will merely produce shoots from
where the cut was made.

East Devon
England

Some plants can re-shoot from dormant buds, others can not, and some can to
start with, then lose the ability as the plant ages and dormant buds die
off.
Ring barking will therefore not always prove fatal, although it will nearly
always do for the section above the ring barking!

--
Charlie, gardening in Cornwall.
http://www.roselandhouse.co.uk
Holders of National Plant Collection of Clematis viticella (cvs)