Lawn in front covered in a lot of fertiliser (5)
I believe the answer is:
mulch
'lawn in front' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
'covered in a lot of fertiliser' is the wordplay.
'covered in' indicates putting letters inside.
'a lot of' becomes 'much' (much can mean a lot of something).
'fertiliser' becomes 'l' (I can't justify this - if you can you should believe this answer much more).
'much' enclosing 'l' is 'MULCH'.
Can you help me to learn more?
(Other definitions for mulch that I've seen before include "Vegetable matter spread to protect roots, etc" , "Mixture of straw, leaves etc spread on ground to protect plants" , "Loose material spread by gardener to protect roots" , "It's laid around plants to retain moisture and keep down weeds" , "Decaying leaves, bark or compost spread around a plant" .)