Wicker sources (6)
I believe the answer is:
osiers
'wicker sources' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for osiers that I've seen before include "Flexible twigs used in basketwork" , "Roses I find with flexible willow twigs" , "Willow twigs used in basket-work" , "Kind of willows for weaving - Rosie's?" , "Willow twigs used in basket-making" .)