[Bec1]

I got some dead flowers on my petunia, do u cut them off and will they regrow back

[mumofstig]

Early in the flowering season, removing dead flowers makes the plant grow more buds.
It stops working towards the end of the usual flowering season as the plant readies for bad weather, or begins to die back if it's an annual.

[Goosegirl]

When their flowers have gone over I nip off the stem just below the flower with my finger nails. Be careful not to nip off a new flower as they can look the same but they have a much firmer feel to their petals.