Feat cutting 101 plants (5)
I believe the answer is:
cacti
'plants' is the definition.
(cactus is a kind of plant)
'feat cutting 101' is the wordplay.
'feat' becomes 'act' (I've seen this in another clue).
'cutting' is an insertion indicator (some letters cut their way into a word).
'101' becomes 'CI' (roman numerals).
'act' placed inside 'ci' is 'CACTI'.
(Other definitions for cacti that I've seen before include "flowers" , "Spiny succulents" , "Spiky plants found in deserts" , "They store water" , "growing group" .)