Last 3 :
11A : Blue soil at rear of rockery (6) : O???H? (the 'O' is from SUPPORT for 1 Down : Taking food in hospital to suppress temperature is wise)
2D : Island's an alternative to a big house (5) : M?N?? - is it MANSE? In which case 11A becomes O?E?H?
10a : Plan a large collection at end of round : D?A?T : DRAFT?
Thanks in anticipation