Low-growing woody plants (6)
I believe the answer is:
shrubs
'low-growing woody plants' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for shrubs that I've seen before include "'Woody plants, bushes (6)'" , "Low woody perennials" , "Small woody plants and bushes" , "low-growing bushes" , "Low, woody, perennial plants" .)