Doctor keeping Gloria under treatment, making a bloomer (8)
I believe the answer is:
marigold
'bloomer' is the definition.
(marigold is a kind of flowering plant)
'doctor keeping gloria under treatment making a' is the wordplay.
I cannot quite understand how this works, but
'doctor' could be 'rig' (I've seen this before) and 'rig' is found in the answer.
'a' is found in the answer.
The remaining letters 'mold' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for marigold that I've seen before include "Orange-flowered plant" , "Orange daisy" , "The flower has a gold rim, oddly" , "Composite plant" , "Bright orange-yellow garden flower" .)