Plant seeds while missing hard ground (9)
I believe the answer is:
edelweiss
'plant' is the definition.
(edelweiss is a kind of plant)
'seeds while missing hard ground' is the wordplay.
'missing' indicates named letters should be taken away.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'ground' indicates an anagram ('grind' the letters into a new form).
'seeds'+'while'='seedswhile'
'seedswhile' with 'h' taken out is 'seedswile'.
'seedswile' anagrammed gives 'EDELWEISS'.
(Other definitions for edelweiss that I've seen before include "Ewe slides on the alpine plant" , "Alpine plant, celebrated in song" , "Swedes lie about small white flower in Switzerland" , "Alpine flower - "The Sound of Music" song" , "I weed less when this flower is around" .)