Clue: Shrubby plant on river spotted rising after time, a real winner (12, 3 words, apostrophe) (12)
Answer: THE BEE’S KNEES
Explanation: Definition: a real winner
**HEBE** ("shrubby plant") *on* (River) **ESK** + **<=SEEN** ("spotted", *rising*) *after* **T** (time)