Tree, even hedges run through border (9)
I believe the answer is:
evergreen
'tree' is the definition.
(I've seen this before)
'even hedges run through border' is the wordplay.
'even' becomes 'e'en' (old-fashioned contraction).
'hedges' means one lot of letters goes inside another (surrounds like a hedge).
'run' becomes 'r' (cricket abbreviation).
'through' indicates putting letters inside (inserted letters go through the word).
'border' becomes 'verge' (verge is a kind of border).
'r' inserted into 'verge' is 'vergre'.
'een' placed around 'vergre' is 'EVERGREEN'.
(Other definitions for evergreen that I've seen before include "Bearing leaves throughout the year" , "Having enduring popularity" , "Ageless" , "The foliage of the trees remains throughout the year" , "Not all shrubs are" .)