Avon,
United Kingdom 
A couple of years ago I bought 2 Buddlias (Sorry, I know that isn't how you spell it!), but these were called something like Buzzlias as they were smaller, designed to live in pots. They have bloomed each year but now the flowers are coming at the top of woody type stems. Should I cut them back at the end of the summer? Thanks.
26 Jul, 2012
Answers
Only trim them in autumn, mostly to deadhead. In the spring, late March to early April, cut them back to about a foot. If they are staying in pots don't forget to renew some of the compost in spring and keep the pots sheltered over the winter.
They sound like Thompson and Morgan's Buzz Buddlejas.
26 Jul, 2012
when the cooler weather decides to show up for autumn prune them back, but not too much, i have the same as you and thats what i do each year and they are fine.
26 Jul, 2012