1: He adopts park tree (5)
4: Perhaps men sit and eat in a cafe (9)
6: Its a firm, small lettuce (3)
7: Taxi omitted going around gnome (5)
9: Sound of river crossing (3)
11: Pious woman in underground hideaway (3)
12: Rebs to can fresh edible crustacean from southern states (5,4)
13: Cleaning aid possessed by Fragonard (3)
15: Child is to depart, finally (3)
17: Uncovered selection is of considerable size (5)
18: Copy of top ten missing (3)
20: Take a turn or a thousand dollars (3)
22: See, you are a cad. (3)
24: Proficient in arithmetic, starting with short division (5)
27: Sister gets nothing, we hear (3)
28: Former name for joint audition (3)