Writing section about border plants (9)
I believe the answer is:
primroses
'plants' is the definition.
(primrose is a kind of plant)
'writing section about border' is the wordplay.
'writing section' becomes 'proses' (I can't justify this - if you can you should give a lot more credence to this answer).
'about' is an insertion indicator.
'border' becomes 'rim' (I've seen this before).
'proses' going around 'rim' is 'PRIMROSES'.
Can you help me to learn more?
(Other definitions for primroses that I've seen before include "plants" , "Promisers or pretty yellow flowers" .)