"Derek" wrote in message
...


I cut them back now to about 4 foot to reduce any windrock in the
winter, but prune hard back in March.


That's how I have pruned for the last twenty years.
--


Thanks everyone for your advice. I think I'll do the above. I have 3 and
they are all huge. After being pruned every year, they almost grow as I
watch them ;-)
Got some Painted Lady butterflies on them this year (boast)

Tina