Horticulturalist (8)
I believe the answer is:
gardener
'horticulturalist' is the definition.
(horticulture is gardening)
This is the entire clue.
(Other definitions for gardener that I've seen before include "he wants to cultivate?" , "one working on plot?" , "He tends cultivated land around house" , "Nursery employee" , "Eg, Capability Brown" .)