In article ,
Jenny M Benson wrote:

Please can someone yay or nay to cutting all the existing "lengths of
wood" back to the lowest buds.

Assuming it is one of the common buddleias, I agree with the other
people - BUT .... Many plants (and I think buddleias are among them)
do not sprout well from very old wood. So I recommend cutting back
to just above the lowest buds on most plants. You don't want to cut
back RIGHT to ground level, either, as they shoot from stems and not
roots - but you can be pretty ruthless.

That's being cautious. Other people may have cut buddleias down right
to ground level and had them shoot - I don't know if that works, and
whether it works on some ages of plant and not others. E.g. you can
kill a seedling or old oak or ash by doing that, but ones older than
a year or two and not yet old will sprout from the stump (coppicing).

That differs from things like bay, which DOES shoot from the roots.
Renovating an old one is done by removing the stem entirely, and it
can be almost impossible to remove :-)


Regards,
Nick Maclaren.