Tahi wrote:
I have a very old berberis darwinii. I spent yesterday reducing its height
again and thinning out the rest so that it is only about nine feet in any
dimension now. That's a wild guess as it is on a slope. Him indoors would
have liked it cut back much further but I dont want to lose it and the
trunks are already bare for the first few feet. How much butchery might it
take?

ISTR that the question was asked on GQT, and the concensus of opinion
was that they're pretty-well impossible to kill.

I cut one right down to the ground - about seven feet high and nine feet
across in all directions (except up, obviously, and I can't comment on
down...)

It kept coming back, even after I'd built a bonfire over it.

I think they should be cut in summer, 'after flowering' but it flowers
fairly continuously from April onwards and still has a few blooms now.

I also have a lavender bush getting taller each year. I believe you can't
cut them hard back without killing them. If, instead of trimming just the
flower stalks away, I carefully cut each stem back to about four leaves or
so, would that help it stay lower? I don't know the variety, but it is
nothing unusual.

I'd take and root cuttings from it before any butchery is undertaken -
lavender is a fickle shrub at the best of times.

--
Rusty