On Sun, 08 Jul 2007 23:27:21 +0100, Frank Booth Snr
wrote:

Well leave it for now until March unless you want to lose most of the
flowering to come later. When you prune you are aiming for an inverted
cone shape with sufficient light and air able to reach the centre of the
shrub. Therefore I'd remove at least a 1/3 to 1/2 of the current old
stems at equal distances around the outside of the shrub. I'd remove
most (not all) of any stems old and new that arise from the central
crown of the plant. Of the old stems that remain I'd hard prune down to
2-3 buds from their base. The newer taller outer stems say (2 yr growth
or less), I'd prune by half their length to the nearest bud. You should
then have a basic symmetrical shape, and will only need to do very light
pruning in the following years, removing ingrowing side branches and
continuing to remove more old stems until they are completely replaced
by the newer ones.

Excellent - thanks for the detail, much obliged.