Race to the trees (4)
I believe the answer is:
oaks
'trees' is the definition.
(oak is a kind of tree)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for oaks that I've seen before include "Acorn trees" , "Epsom Classic race" , "Soak up with trees" , "Horse race - trees" , "Acorn producers" .)