Grow crop, last of rye bordering vital ground (9)
I believe the answer is:
cultivate
'grow' is the definition.
(thesaurus)
'crop last of rye bordering vital ground' is the wordplay.
'crop' becomes 'cut'.
'last of' suggests the final letters.
'bordering' means one lot of letters goes inside another.
'ground' indicates an anagram (grind the letters ).
The last letter of 'rye' is 'e'.
'cut'+'e'='cute'
'vital' anagrammed gives 'ltiva'.
'cute' enclosing 'ltiva' is 'CULTIVATE'.
(Other definitions for cultivate that I've seen before include "Foster" , "Promote" , "Try to get in with" , "Grow (crops)" .)