Crossword Genius

Fair about father, concerning energy growth (5,4)

Ross

I believe the answer is:

judas tree

I'm a little stuck... Click here to teach me more about this clue!

'growth' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'fair about father concerning energy' is the wordplay.
I cannot quite understand how this works, but
'about' could be 're' ('re' means regarding or about) and 're' is located in the answer.
'father' could be 'da' (I've seen this in other clues) and 'da' is located in the answer.
'fair' could be 'just' (associated in meaning) and 'just' is found in the leftover letters.
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

(Other definitions for judas tree that I've seen before include "girl!" , "woody plant" .)

I've seen this clue in the Sydney Morning Herald.
Want a hint initially instead of a full solution? Install my app