BiG Orange wrote:

Second is improper pruning
If you prune back too late, you will be removing next season's flowers.
Also,

Pam, when do you prune and how much?

Prune right after blooming, usually no later than June (at least in my area).
Cut out dead wood and remove spent flower heads (not necessary for next
year's flowering but it tidies things up nicely). You can reduce growth by no
more than a fourth to a third at this time, although I prefer to do major
renovational pruning in winter when the shrubs are dormant. You'll lose some
flowering, obviously, but it is far easier on the shrub to do hard pruning
when they are dormant.

pam - gardengal