Ants got in the tub my 'blood red' was in with erecaceous soil so garden centre advised to put in the soil. I did this last Autumn. This year the leaves are not their usual brilliant red but a dull red and green on the underside. Is there anything I can do to restore it to it's former glory?
Try giving it a nitrogen-rich feed next spring.
Acers don't need ericaceous soil, and if your plant had been in the tub for a long time it may have been hungry. Very acid soil can also make leaves a more intense red, but it can mean that the plant is unhappy.
Also, many red acers get a bit greener as the year goes on, then develop the stunning red leaves of autumn as they get ready to fall later on. Mine certainly do not have ericaceous compost, though once in a rare while I do give them an iron feed. Have bought a new coral leafed one this year, still quite green but developing the coral colour as it grows up - very young yet.
Good advice from Alina W and Bookerto. I find red acers need almost full sun. They do not like full shade. I would give it more sun and as long as the soil is moist and out of wind (more important then sun) then it will be fine.
Thanks everyone, the blood red is in the full sun but can get a bit windy in my garden. I will give it a good feed in the spring and a mulch which hopefully will improve things, saying this it is a very healthy looking tree.