Organic flower fertiliser (6)
I believe the answer is:
pollen
This might be a double definition.
'organic flower' is the first definition.
The definition and answer can be both plants as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'fertiliser' is the second definition.
(pollen fertilises plants)
Can you help me to learn more?
(Other definitions for pollen that I've seen before include "Airborne 10 across" , "What sticks to insects" , "Seed released by plant" , "Fine powder produced by the anthers of seed-bearing plants" , "Cause of hay fever" .)