Plant once more on television (5)
I believe the answer is:
reset
'plant once more' is the definition.
('set' can be a synonym for 'plant' so perhaps 'reset' is OK for 'plant once more')
'on television' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'television' becomes 'set' (I've seen this in other clues).
're'+'set'='RESET'
(Other definitions for reset that I've seen before include "Trees (anag)" , "button on electronic device?" , "Replanted" , "Replace, resettle or put back again" , "Restore to the initial readings" .)