Work in the garden every other weekend (4)
I believe the answer is:
weed
'work in the garden' is the definition.
'every other weekend' is the wordplay.
'every other' indicates alternate letters.
The alternate letters of 'weekend' are 'WEED'.
(Other definitions for weed that I've seen before include "Wild unwanted plant - tobacco?" , "Went" , "Intrusive plant; weak person" , "Made water" , "Cannabis; feeble person" .)