On Tue, 7 Jun 2011 14:11:44 -0700 (PDT), Dave Hill
wrote:

On Jun 7, 9:39*pm, Charlotte Grant wrote:
I have a buddleja davidii that I want to keep to 4ft height, 3ft spread.
What pruning regime should I follow please?

but Davidii will get a lot biger, I've had flowering spikes over 6ft
long on a mature bush

Cut back very hard in the Autumn, and then again in spring, (first is
to stop the trunk splitting due to carrying too much weight and wind
rock.)
The second prune encourages new growth.

Mine is over thirty years old, (might be over 40 ) base is a
magnificent gnarled work of art, but I now I cut everything back to
where it begins to sprout, about a couple of feet up the trunk. It
will easily make 10ft high, side branches are cut back if they get in
the way during the summer.,

Then next spring its brought back to about 2ft high.

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