Crossword Genius

Regularly we climb tree (3)

Ross

I believe the answer is:

elm

Here is my best explanation:

'tree' is the definition.
(elm tree is a kind of tree)

'regularly we climb' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'we'+'climb'='weclimb'
The alternate letters of 'weclimb' are 'ELM'.

This clue was last seen in The Times