Answers are blooms/growths of what looks like a flower or plant but are wild weeds that grow where not wanted
No. 2. Nor is this one a squealer (9)
No. 4. Top prize for a field goat (9).
No. 7. Corner the market although unwanted. (7)
No. 8. Stylish bird smokes a joint (9)
No. 17. Unwanted one will attach and smother the blooms (8)