Shrubs faring badly in ashy garden (10)

I believe the answer is:

hydrangeas

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

'shrubs' is the definition.
(hydrangea is a kind of shrub)

'faring badly in ashy garden' is the wordplay.
'ashy garden' can be anagrammed to 'HYDRANGEAS'.
However, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for hydrangeas that I've seen before include "Garden shrubs" , "Flowering plants; ashy garden (anag.)" .)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app