Well placed facing one's plant (12)
I believe the answer is:
satisfactory
'well' is the definition.
(similar in meaning)
'placed facing one's plant' is the wordplay.
'placed facing one's' becomes 'satis' (I can't explain this - if you can you should give a lot more credence to this answer).
'plant' becomes 'factory'.
'satis'+'factory'='SATISFACTORY'
Can you help me to learn more?
(Other definitions for satisfactory that I've seen before include "Meeting expectations" , "Fully acceptable" , "fine" , "Acceptable - adequate" , "Fulfilling expectations" .)