Lawn starter (3)
I believe the answer is:
sod
'lawn starter' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sod that I've seen before include "'Sward, turf (3)'" , "Piece of grassy soil" , "Lump of turf or unpleasant person" , "A lulmp of turf" , "Piece of ground with a mat of grass" .)