What to Do With Dead Flowers?

by Jenny Harrington

Plants form seed pods after the flower dies.

All flowers eventually wilt, their flush of beauty only temporary.
Removing the old dead flowers properly can force a new flush of blossoms or encourage further healthy growth.
 Cutting off the dead blooms properly depends on the type of plant
and whether you want it to grow seeds.
Improper removal can slow flowering or affect the health of your flowering plants.

Basic Deadheading

Most annual and perennial flowers benefit from deadheading.
 Plant varieties that flower repeatedly throughout the season may produce more flowers
if you remove the old blossoms before seeds form,
and it also improves the appearance of the bed.
 Pinch off the old flowers above the topmost set of leaves on each stem.
If the plant grows multiple flowers on a long stem,
 cut back the entire stem after most of the flowers are done blooming. You can deadhead after each major flush of blooms begins to fade, or you can pinch off the old blooms once or twice weekly throughout the flowering period.

Woody Plant Deadheading

Flowering bushes and other woody plants, such as roses,
 require sharp bypass shears for healthy deadheading.
For most woody plants, cut the old flowers off within 1/4 inch of the closest leaf or bud
 to the old flower.
When deadheading roses, make the cut within 1/4 inch of an outward 
facing bud near a three- or five-leaf grouping. 

Deadheading woody plants is a form of pruning, so keep in mind the desired shape of the plant when removing flowers and stems.

Deadheading Once-Bloomers

Once-blooming flowers, such as daffodils, tulips and peonies,
 won't produce more flowers if you remove the dead flowers,
but they will look better and remain healthier.
Cut or pinch off the old flowers as soon as they wilt.
You can cut back the flower stems to the foliage to improve the appearance of the plant,
but don't remove the leaves until they die back naturally because
they provide greenery and collect nutrients for the plant.

Setting Seed

Some annuals and short-lived perennials, including cosmos, violas and petunias, readily reseed themselves, so you don't have to replant them each year.
Other varieties, such as echinacea, produce attractive seedheads
that also provide seed for birds in winter.
Leave the dead flowers on these plant varieties if you want them to seed themselves
or provide ornamental seed heads later in the year.

Cleanup

Dead flowers left in the garden can provide material for disease organisms to grow on, 

or they may allow pests to nest in the garden and later attack your plants. 

Dispose of removed flowers immediately. 

Adding the old blooms to a compost pile allows them to break down 

and later provide nutrients to the bed, or you can dispose of the flowers in the garbage. 

SOURCE: http://homeguides.sfgate.com/dead-flowers-61279.html