Risk of garden growing wild (6)
I believe the answer is:
danger
'risk' is the definition.
(I know that risk can be written as danger)
'garden growing wild' is the wordplay.
'growing wild' is an anagram indicator.
'garden' is an anagram of 'DANGER'.
'of' acts as a link.
(Other definitions for danger that I've seen before include "Ranged about in some peril" , "Garden (anag) - peril" , "'Peril, risk (6)'" , "Peril in garde" , "Insecurity" .)