Yes he'd a scattering of grass fragments (7)
I believe the answer is:
hayseed
'yes he'd a scattering of grass fragments' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'yes he'd a scattering' is the wordplay.
'scattering' is an anagram indicator.
'yes'+'hed'+'a'='yesheda'
'yesheda' with letters rearranged gives 'HAYSEED'.
Can you help me to learn more?
(Other definitions for hayseed that I've seen before include "Had eyes (anag.)" , "Yokel" , "Countryman" , "Simple country person" , "Rustic" .)