It looks as though it is starved and needs a really good feed,Redmaple..and they soon get very dry,especially in a pot..A tree this size would be much better off in the ground..If you dug out a lot of the soil,and replaced with Ericaceous compost..I'm sure it would be ok..I don't have the correct soil either..but mine does really well..they need lots of water in the summer,to form buds for this time of year..and if you have a north facing position,it would be ideal..I would be very disappointed if I had paid so much for one....although to be honest,I wouldn't ...

I agree, a good ericaceous feed 3-4 times a year, keep it moist and it will look much greener. I would be tempted to move it to semi-shade as it will dry out too quickly in full sun.

The pot's too small - needs a much bigger container is my guess, with fresh ericaceous compost, although I can't see how deep the current pot is from the picture. I'd buy a much larger pot and the compost, then turn out the plant when those three flowers are done, repot and prune it back by a third. Keep well watered, ensure good drainage in the pot, keep the pot off the ground by using something like pot feet to have a small gap between the pot and the surface beneath.

Thanks to one and all. I know the pot looks small in the pic. but i assure you it's not. Anyway, today i bought some ericasous food for it and put the pot on stands. So will see how it goes!

Once again - thanks

For a shrub with that sort of height and thickness of stem, I'd expect the container to be a minimum of 2, but preferably 3 feet deep or more, and 2 feet wide.