Is it Buddleia globosa? It probably needs more water. We have had no rain here for about 8 weeks so things are looking dry. I cut my buddleias back to a couple of feet high at the end of last year and they bounce back with strong new growth. Maybe a good prune will do the trick.

Hi, welcome to GoY, I agree with Thorneyside, it is B globosa, but while most species of Buddleja are pruning group 6, 'globosa' is pruning group 2, and needs minimal pruning, however on mature plants, you can cut back about one fifth, to one quarter of the oldest growth to the base, to encourage repacement growth lower down, do it annually after flowering, in the meantime give it a feed of some general purpose fertilizer, such as growmore, and keep it well watered.
The ultimate height and spread of this is about 15ft, Derek.

That looks normal for a mature Buddleja globosa.

We had a mild winter and many of the old leaves weren't lost so they are shedding them now. There is plenty of new growth with the flowers and, once they have finished, there will be more new growth.

Derekm is right - pruning after flowering (up to mid-July) and it will regrow enough to flower again next May/June.

My page about B. globosa:
http://www.buddlejagarden.co.uk/globosa.html

Hi, thanks for all your replies. I hate to lose plants when I've watched them grow over the years. I put into action all your advice. Jan

You could leave the new shoots coming from the base
They will grow up to replace the old wood that you take out.