Harvest the Flowers When your sunflowers start to droop on their stems, use a sharp knife to cut the sunflower heads from the plant. Leave about 6 to 12 inches of stem attached to each bloom.

Experts have shared their top tip on how to keep these cheerful flowers fresh for longer after they've been cut or purchased ...

If your sunflower heads have already started to droop, don’t worry. David says you can revive them by re-cutting the stems and placing them in fresh water to give them a boost.