Hi, Bev!
Leave it to someone from northern Illinois to try and answer a South Carolina gardening question!
Here goes...
In the frozen north, buddleias are deciduous (loose their leaves in the fall) and are cut back almost to the ground. (Don't run screaming in shock yet!) If your Butterfly bush (buddleia) loses its leaves for winter, you'll have a much nicer, well behaved, fuller bush if you do just such a drastic pruning since the
plant only blooms on the current year's growth. This type of pruning means cutting back the entire bush way down to the permanent framework (removing 90% of the
plant). It's just like cutting back a Caryopteris or Russian Sage.
A MAJOR NOTE: Buddleias fall into 2-3 different pruning categories so if you know the name of the cultivar you have, e-mail me and I'll get you the exact info regarding pruning. The most popular cultivars around here are Buddleia davidii: Black Knight; Empire Blue; Nanho Blue, Purple and White; and the new Honycomb (if you can find it).
Look forward to hearing from you and hope this wasn't too confusing!
Barb
zone 5