Their clocks show when it's time to spread their seeds (10)

'seeds' is the definition.
The answer and definition can be both plants as well as being plural nouns.
Perhaps you can see a link between them that I don't see?

'their clocks show when it's time to spread their' is the wordplay.
I cannot really see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is found within the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?