Plants used around the start of the play (5)
I believe the answer is:
cacti
'plants' is the definition.
(cactus is a kind of plant)
'used around the start of the play' is the wordplay.
'used' becomes 'dedicated' (dedicating is a kind of using).
'around' means to look at the middle letters.
'the start of the play' becomes 'acti' (I can't justify this - if you can you should give a lot more credence to this answer).
The middle letter of 'dedicated' is 'c'.
'c'+'acti'='CACTI'
Can you help me to learn more?
(Other definitions for cacti that I've seen before include "Plants of dry regions" , "They're decidedly prickly" , "Prickly types" , "Tough plants" , "growing group" .)