South Kentucky salad plant to shoot up (9)
I believe the answer is:
skyrocket
'shoot up' is the definition.
(thesaurus)
'south kentucky salad plant' is the wordplay.
'south' becomes 's' (abbreviation).
'kentucky' becomes 'ky' (abbreviation).
'salad plant' becomes 'rocket' (I've seen this before).
's'+'ky'+'rocket'='SKYROCKET'
'to' is the link.
(Other definitions for skyrocket that I've seen before include "seen to shoot up" , "Shoot up high" , "Rapidly appreciate" , "Increase very rapidly" , "Shoot up abruptly" .)