Plant found in March maybe, hidden in grass (8)
I believe the answer is:
marjoram
'plant' is the definition.
'march maybe hidden in grass' is the wordplay.
'march maybe' becomes 'Jo' (Jo March is a character in Little Women).
'hidden in' is an insertion indicator.
'grass' becomes 'marram' (marram is a type of grass).
'jo' put inside 'marram' is 'MARJORAM'.
'found in' acts as a link.
(Other definitions for marjoram that I've seen before include "Herb used in cooking - a Mr Major (anag)" , "Herb, maybe oregano" , "found with Rosemary in the kitchen?" , "Food seasoning also called oregano" , "Aromatic mint relative" .)