Tries to change, keeping lines as framework for growth (7)
I believe the answer is:
trellis
'framework for growth' is the definition.
'tries to change keeping lines' is the wordplay.
'to change' indicates an anagram.
'keeping' means one lot of letters goes inside another.
'lines' becomes 'll' (I've seen this in other clues**).
'tries' with letters rearranged gives 'treis'.
'treis' going around 'll' is 'TRELLIS'.
'as' acts as a link.
(Other definitions for trellis that I've seen before include "Framework for creepers" , "Support for climbing plants" , "trainer" , "Frame for creepers" , "Garden lattice" .)