Cat takes to a new plant (6)
I believe the answer is:
tomato
'plant' is the definition.
(I know that tomato is a food crop)
'cat takes to a new' is the wordplay.
'cat' becomes 'tom' (a tom is a male cat).
'takes' is an insertion indicator (take can mean to capture or invade).
'new' indicates anagramming the letters.
'to'+'a'='toa'
'toa' is an anagram of 'ato'.
'tom' put inside 'ato' is 'TOMATO'.
(Other definitions for tomato that I've seen before include "Fruit, often used as vegetable" , "A motto, strangely, for this fruit" , "Love apple (archaic)" , "Part of a BLT sandwich" , "A glossy red fruit eaten as a vegetable" .)