Where to find tender borders of rosemary (7)
I believe the answer is:
nursery
'where to' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'tender borders of rosemary' is the wordplay.
'tender' becomes 'nurse' (someone who tends to patients).
'borders of' means to remove the middle letters.
'rosemary' with its middle taken out is 'ry'.
'nurse'+'ry'='NURSERY'
'find' acts as a link.
(Other definitions for nursery that I've seen before include "Place where young plants are grown" , "where bloomers may be the order of the day?" , "sort of rhyme" , "Where kids learn" , "place for promising growth?" .)