Planet you start to find vulgar (6)
I believe the answer is:
earthy
'vulgar' is the definition.
(I know that vulgar can be written as earthy)
'planet you start to' is the wordplay.
'planet' becomes 'earth' (Earth is an example).
'start to' suggests taking the first letters.
The initial letter of 'you' is 'y'.
'earth'+'y'='EARTHY'
'find' acts as a link.
(Other definitions for earthy that I've seen before include "Head covering" , "Coarse, vulgar" , "Consisting of soil" , "Coarse; unsophisticated" , "Gross, unrefined" .)