Tiny tip one’s left in main plant (5,3)
I believe the answer is:
sweet pea
'plant' is the definition.
(sweet pea is a kind of plant)
'tiny tip one's left in main' is the wordplay.
'tiny' becomes 'wee' (I've seen this before).
'tip one's left' becomes 'tp' (I am not sure about this - if you are sure you should believe this answer much more).
'in' indicates putting letters inside.
'main' becomes 'sea' ('sea' can be a synonym of 'main').
'wee'+'tp'='weetp'
'weetp' put within 'sea' is 'SWEET PEA'.
Can you help me to learn more?
(Other definitions for sweet pea that I've seen before include "Climbing garden plant - saw tepee (anag)" , "Climbing pant" , "Fragrant flower" , "Eat, weeps and gets climbing flowers" , "Climbing plant with pastel-coloured flowers" .)