Framework for growth regularly gets less healthy-looking, I admitted (8)
I believe the answer is:
espalier
'framework for growth' is the definition.
(framework for growing plants)
'regularly gets less healthy-looking i admitted' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'less healthy looking' becomes 'paler' (an unwell person may look pale).
'admitted' is an insertion indicator.
The alternate letters of 'gets' are 'es'.
'paler' enclosing 'i' is 'palier'.
'es'+'palier'='ESPALIER'
(Other definitions for espalier that I've seen before include "fruit tree forced flat" , "train a plant" , "Climbing trellis" , "Lattice for growing plants" , "Wood used for lattice work" .)