Debts regularly seen to support scheme with regard to energy growth (5,4)
I believe the answer is:
plane tree
'growth' is the definition.
(I've seen this before)
'debts regularly seen to support scheme with regard to energy' is the wordplay.
'regularly seen' indicates alternate letters.
'to support' means one lot of letters go next to another.
'scheme' becomes 'plan' (I've seen this before).
'with regard' becomes 're'.
'to energy' becomes 'e' (physics symbol as in E=mc2).
The alternating letters of 'debts' are 'et'.
'et' after 'plan' is 'planet'.
'planet'+'re'+'e'='PLANE-TREE'
(Other definitions for plane tree that I've seen before include "It sheds its bark" , "Common city plant" , "growth" , "maple" .)