One's usually needled when neighbours go bare (7)
I believe the answer is:
conifer
'one's usually needled' is the definition.
(conifers typically have needles)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for conifer that I've seen before include "The tree keeps its leaves" , "Evergreen (generally)" , "In force (anag.)" , "Tree such as pine, yew etc" , "E.g. yew, pine or fir" .)