Loafer first to start work in garden (4)
I believe the answer is:
shoe
'loafer' is the definition.
(I've seen this in another clue)
'first to start work in garden' is the wordplay.
'first to' indicates taking the first letters.
'work in garden' becomes 'hoe' ().
The first letter of 'start' is 's'.
's'+'hoe'='SHOE'
(Other definitions for shoe that I've seen before include "Slingback, for example" , "Trainer maybe" , "What's worn" , "Covering for foot" , "Work as a farrier" .)