when to cut back a hebe planted in ground
By Smurf52
United Kingdom 
it as just finished flowering but has new growth
6 Aug, 2009
Answers
The RHS advice is to cut them back to new growth in June. I think you'd be OK doing it now, though. Certainly no later, as Steve says!
6 Aug, 2009
Previous question
i would be tempted to cut it back a bit now, if you leave it till later on and the new growth is too long, you will forgo the flowers for next year.
6 Aug, 2009