Planting Acer Maple

Hi,

I have recently moved into a new build house and and in the process of sorting out our garden. I am a newbie to gardening but learning everyday

I have recently bought 2 x 6ft Acer Maple Tree's and have two sectiion in my garden where there was turf but had been cut out and is now soil. The soil is full of rubble and is not the best. I have read how the Acer's mostly require ericaceous compost, but am not sure how to plant:

Should I
a) Plant the acer in a larger pot full of fresh ericaceous compost, and then plant the pot in the garden soil. I prefer this option if it does not harm the acer as I wont need as much ericaceous compost.

b) Dig a large size hole in the garden and fill it with large amount of ericaceous compost and then plant the acer (just a little worried its close to the over soil which might harm the acer)

Any help is appreciated.