they don't like chalky, alkaline conditions - multi purpose will do, or John Innes No. 2, or you can use ericaceous compost, though ericaceous is not essential by any means.

it should be free-draining too, particularly if you're going to be growing in a pot of some kind.

You may well need to add grit,composted bark, perlite etc. to open up and improve the drainage of most commercially available composts.