How do you deadhead annuals?

Answer 1

When someone says to deadhead your flowers they mean that you need to take the dead/dying flowers off your plants. Most of the answers above explain how to do this.
Not all plants need this. Those that do will go to seed/stop flowering if you don't. When plants are allowed to go to seed they will die after producing seeds where there was once flowers. You will learn with experience which ones will need deadheading. You can also learn more by going to some of the plant web-sites you see on some of the plant answers on this site.
When you think about the real reason we have flowering plants, it makes sense - it is because all plants need to produce seeds to propagate/continue to reproduce themselves.
When we want to continue enjoying some flowering plants we have to fool them into continuing to make flowers. We do this by deadheading/picking off the dead flowers. Since we take the dead/dying flowers off, this fools the plant into producing more flowers.
I don't recommend letting the flowers get too far into the dying stage before you deadhead. If you let the flowers go too long your plant may begin the dying process and this sometimes makes saving them difficult. I usually pinch mine off as soon as I see them start wilting.
I hope this has been helpful.
Good Luck - enjoy your gardening - it can be very rewarding!!

Answer 2

Yeah, just pop off the heads. If you have a flower with a long stem, the naked stem w/0 a flower might look funny so trim that back to the foliage level. 90% of the time just pop the flower as it fades and before it starts to set seeds.

Answer 3

you just pop the flowerhead off right under the petiole or just where the flower stem ends and the flower begins.

Answer 4

When the flowers wilt and turn brown its time to dead head.