Side wheels — not hard to make a bloomer (9)
I believe the answer is:
edelweiss
'a bloomer' is the definition.
(edelweiss is a kind of flowering plant)
'side wheels not hard to make' is the wordplay.
'not' is a deletion indicator.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to make' indicates anagramming the letters.
'side'+'wheels'='sidewheels'
'sidewheels' with 'h' taken out is 'sideweels'.
'sideweels' with letters rearranged gives 'EDELWEISS'.
(Other definitions for edelweiss that I've seen before include "White-flowered alpine plant" , "Sound of Music plant" , "Ewe slides on the alpine plant" , "high growth" , "flower as national symbol" .)