What farmer sows bears wonder plant (7)
I believe the answer is:
seaweed
'what farmer sows' is the definition.
I can't tell whether this defines the answer.
'wonder plant' is the wordplay.
I cannot really see how this works, but
'wonder' could be 'awe' (awe is a kind of wonder) and 'awe' is present in the answer.
'plant' could be 'seed' (seed plant is a kind of plant) and 'seed' is found in the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'bears' is the link.
Can you help me to learn more?
(Other definitions for seaweed that I've seen before include "Marine growth" , "Laver perhaps" , "What may be cast up on shore" , "water plant" , "what's been washed up" .)