Will he cure plane sickness? (4,6)

I believe the answer is:

tree doctor

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

'will he cure' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'plane sickness?' is the wordplay.
'plane' becomes 'tree' (plane tree is a type of tree).
'sickness?' becomes 'doctor' (I can't justify this - if you can you should give a lot more credence to this answer).
'tree'+'doctor'='TREE DOCTOR'

Can you help me to learn more?

I've seen this clue in The Globe and Mail and The Irish News.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.