It looks like the pot is too small...nows the time to repot it Dave...use a mix of multi compost and ericaceous compost. Acers don't really need prunning,just a tidy up would be sufficient...I find here the dark leaved Acers are happy in sunlight.They need this to develop the dark leaves...dappled shade is perfect.

I agree it needs a bigger pot.

Thanks guys for the advice meadowland what do you mean by a tidy up?

Just a clip here and there to balance it up ...just minimally.

Thanks again meadowland the Acer looks better already now Do you know anything about hydrangea I've asked a question and posted a pic the thing is it nearly but never blooms? It looks healthy enough?

Dave,I'm sorry my Hydrangea knowledge isn't very good...it's only this summer I bought my first!I'm sure other members will know so much more to help you.

The best time to prune acers is in the winter when they are dormant. Large cuts tend to bleed sap and may kill the tree