Gardening suit? (6)
I believe the answer is:
spades
'suit?' is the definition.
(playing card suit)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for spades that I've seen before include "Digging implements" , "Suit in pack of cards" , "Does some groundwork" , "Passed around with diggers" , "dark suit" .)