By Jeanie65
Surrey,
United Kingdom 
A budlea sort of tree that provides privacy needs a prune but don't know where to start-want to keep it but in a manageable way...thanks if you reply.
31 Aug, 2016
Previous question
It looks like a Buddleja davidii, the usual sort. It is all top growth; normally it would sprout from lower on the plant.
For now reduce the height to the height of the shed, but no further until next April; that will encourage dormant buds to emerge lower down.
In the spring, in April not March, cut it as far back as you wish and new growth should emerge from the dormant buds you have stmulated. You will have many more flowers and a more stable plant. Repeat the process every year, remembering to feed with a high-potash fertiliser occasionly.
31 Aug, 2016