Plant almost mature by Resurrection time (8)
I believe the answer is:
oleaster
'plant almost mature by resurrection time' is the definition.
'oleaster' can be an answer for 'plant' (I've seen this before). I am unsure of the 'almost mature by resurrection time' bit.
'plant almost mature by' is the wordplay.
'plant' becomes 'aster'.
'almost mature' becomes 'ole' (I am not sure about this - if you are sure you should believe this answer much more).
'by' is a charade indicator (letters next to each other).
'aster' put after 'ole' is 'OLEASTER'.
Can you help me to learn more?
(Other definitions for oleaster that I've seen before include "Tree" , "Shrub; steel oar (anag.)" , "One produces fruit" , "Shrub like an olive" , "Plant" .)