Fruit is planted in wet weather (6)
I believe the answer is:
raisin
'fruit' is the definition.
(raisin is a kind of fruit)
'is planted in wet weather' is the wordplay.
'planted in' is an insertion indicator.
'wet weather' becomes 'rain' (rain is wet weather).
'is' placed into 'rain' is 'RAISIN'.
(Other definitions for raisin that I've seen before include "Partially dried grape" , "Large dried grape" , "Dried grape used in cakes" , "Fruit for the Christmas cake" , "Dried red grape" .)