Plant in garden I pulled up (5)
I believe the answer is:
lupin
'plant' is the definition.
(lupin is a kind of plant)
'in garden i pulled up' is the wordplay.
'in' says the answer is hidden in the clue.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'nipul' is hidden in the letters of 'garden i pulled'.
'nipul' back-to-front is 'LUPIN'.
(Other definitions for lupin that I've seen before include "Spiky flower" , "Tall-spiked plant" , "It has tall flower spike" , "Garden plant of the pea family" , "Tall-spiked flower" .)