I have 3 Acers, 2 Emperors and 2 Bloodgoods. 2 are in pots. ALL of them do VERY well using moisture control potting soil and garden soil by Miracle Grow, in blue bags. I add to the soil at the beginning of Summer and again in February. They are still beautiful and full. I just transferred an Emperor to the front of the house using this soil and am getting large healthy red leaves

At this time of the year in the UK no feed should be given to any tree, shrub or perennial. Wait until spring and then use an ericaceous feed if you really feel the need. Better to remove the first few inches of soil and replace with new compost.

as MG say's lean towards acid soil, neutral is ok also. Blood/fish/bone is excellent to top-dress your plants when you refresh the compost next Spring.
A general liquid feed in the Summer will also keep them ticking along nicely till dormancy.

Good old leaf mould, it's the best. Gentle on the hands, the plants, and the ground. W

I agree Worthy

Manythanks all who answered.
Frost now the concern. If they get through that (and what else is to come) all should be well.
Wishing all members a happy festive season, useful gifts and a well-deserved break before a productive spring.
Take care all and thanks again for being an invaluable resource.
Kind regards,
Barry Walsh