Mine is that height but still a baby young plant I bought last year Angie.

I am not going to prune mine as Want it a lot taller for privacy where its planted.

Its been a great sunny day Angie.

I cut mine back mercilessly regardless of whether it has leaves or not and it carries on regardless.

Scotkat you might want to reconsider and prune otherwise there will only be leaves and flowers up towards the top of the stems and the lower half will be bare stems. A buddleja can easily grow two to three metres in a year. If you need a shrub which taller than this look to something different.

It was new last yr MG and has not grown too much .

I dont want anything different.

Its a varigated Buddleja

Buddleja davidii cultivation notes: This Buddleia will flourish in most well drained soils, especially chalk. Plant in full sun for the best show of flowers. Keeping pruning to a minimum and plant at back of border to allow space to grow.

I copied and pasted this info for you MG.

So in this note I did plant at back of garden and I have not pruned as it had not bloomed last year.

Prune as normal in late March for July-August flowering regardless of how the winter foliage has developed. With variegated cultivars always prune with a little more caution as excessive cutting back can encourage reversion to plain green.
I would also say there isn't a B. davidii 'Blue Emperor', it is probably 'Empire Blue' as it looks tall and upright; 'Purple Emperor' is a dwarf with narrow leaves. Shameless plug: plenty more info on my website.

Thanks all - Buddleja Garden, just got my names mixed up - I've far to many 'emperors' in this garden. You are right it is Empire Blue, doh! :)

I have read these answers with much interest as I have a Buddleja Black Knight .The label advised pruning in March but did not say how hard.There seems to be conflicting ideas.I have mine in a large pot &it grew well last year,which was its first.March is nearly here & its started to come into leaf.WHAT SHALL I DO?

Hanchy - I was a bit early in pruning last year, mainly because I had to move it from a spot it wasn't happy in and it was easier to prune to move it.
I will be leaving it until late March as seems to be the general consensus of opinion above.
They get very large if left without pruning, it's all a matter of taste and what space you have.

Hanchy as your buddleja is in a container you will need to prune some time next month or it will become top heavy.