Grew fashionable fruit (7)
I believe the answer is:
rosehip
'fruit' is the definition.
(fruit of a rose plant)
'grew fashionable' is the wordplay.
'grew' becomes 'rose' (rise can mean to grow or increase).
'fashionable' becomes 'hip' (I've seen this in another clue).
'rose'+'hip'='ROSEHIP'
(Other definitions for rosehip that I've seen before include "Wayside fruit" , "Fruit of flower used for syrup" , "Fruit of the brier" , "Hedgerow or garden fruit" , "Wild fruit for syrup" .)