Moss rose leggy, appears exhausted
I have been growing moss rose for over 15 years now and they have always thrived here in Atlanta. Goodness knows we have the heat and the average level of humidity makes caring for these just about as easy as possible. This year I planted them as usual (I am a container gardener) and, as usual, they took off with huge gorgeous blooms in no time. Now that we are late in the summer, I am seeing something I have never seen before with these flowers: they are far too leggy and look rather ragged despite that they continue to bloom.
I know these normally do not require deadheading let alone pruning but they just look terribly tired. Any idea what would happen if I pruned them back? Will I just kill them if I do so?
Thanks for any and all advice!