Plant a bit of privet in front of the church (5)
I believe the answer is:
vetch
'plant' is the definition.
(vetch is a kind of plant)
'a bit of privet in front of the church' is the wordplay.
'a bit of privet in front of' becomes 've' (I can't explain this - if you can you should give a lot more credence to this answer).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'church' becomes 'ch' (common abbreviation).
've'+'t'+'ch'='VETCH'
Can you help me to learn more?
(Other definitions for vetch that I've seen before include "Weed" , "Leguminous plant" , "Climber" , "Wild climbing plant" , "Climbing plant of the pea family, cultivated as fodder" .)