What farmer sows bears wonder plant (7)
I believe the answer is:
seaweed
'what farmer sows' is the definition.
I can't judge whether this defines the answer.
'wonder plant' is the wordplay.
I cannot quite understand how this works, but
'wonder' could be 'awe' (awe is a kind of wonder) and 'awe' is found within the answer.
'plant' could be 'seed' (seed plant is a kind of plant) and 'seed' is located in the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
'bears' acts as a 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" .)