Care about shrub (4)
I believe the answer is:
acer
'shrub' is the definition.
(I've seen this before)
'care about' is the wordplay.
'about' is an anagram indicator.
'care' is an anagram of 'ACER'.
(Other definitions for acer that I've seen before include "Tree with winged fruit" , "Care about the maple?" , "ornamental tree" , "Tree of maple family" , "Care about this tree" .)