On 7/10/2014 1:12 AM, Sam Wilburton wrote:
is it better to trim them when flowering?
or in the winter?
or summer?

It depends upon the shrub and your local climate. But the general rule
of thumb for flowering shrubs is: spring flowering shrubs should be
pruned right after they're done blooming, summer flowering shrubs get
pruned in late winter/early spring.