Deadheading flowers: What, when and why we do this?

Deadheading spent blooms keeps flowers producing all summer long while helping gardens stay colorful, tidy and healthy.

Plants produce flowers for a reason — to reproduce. Once flowers are pollinated, plants shift their energy into nurturing developing seeds rather than producing new blooms. We can trick plants into developing more flowers by removing spent blooms, a pruning technique called deadheading. Deadheading also keeps plants looking their best by cleaning up faded flowers. Most annual plants and many perennials benefit from deadheading to promote new growth and continuous flowering.

How deadheading works

When we deadhead fading flowers, we prevent pollinated blooms from developing seeds. This prompts plants to try again with another flush of flowers. By repeatedly deadheading spent blooms throughout summer, you keep plants in the flowering stage, providing long-lasting color.

Deadheading is easy to do; simply pinch or cut flower stems back as blooms begin to fade. Although many plants drop spent flowers on their own, the ovary (and developing seed) doesn’t fall off. This is why we cut or pinch flower stems back and don’t simply pull off the petals. Pinch flower stems between your thumb nail and forefinger or use sharp pruners or flower snips for tougher stems. Cut just above the next set of leaves or a side branch. For roses, cut canes back to the first set of leaves with five leaflets.

Some gardeners like to cut stems back by one-third to one-half when deadheading to manage plant size, remove leggy growth or deadhead flower clusters that cover shoot tips. This type of pruning encourages branching and new growth. To maintain blooms while reducing plant size, cut back a few stems at a time over a few weeks. Plants may take a week to two to put on new blooms, depending on the species and how much material you trimmed.

When to deadhead plants

Deadheading is timed according to a plant’s bloom cycle and varies by species. Begin deadheading when flower colors visibly dull and fade or when you see petals begin to shrivel and turn brown. If you notice seed pods developing where flowers naturally fell away, go ahead and cut these off. Walk the garden regularly once flowers begin to fade to remove spent blooms. Deadheading tends to come in waves. After the initial flush of flowers, you may experience a lull until the next wave matures.

For many plants, it is beneficial to reduce or stop deadheading toward the end of the season. This allows plants like zinnias, hollyhock and cleome to produce a crop of seed for next year’s plants. Many perennials, like echinacea, rudbeckia and liatris, produce lovely seed heads that not only look good in winter but also feed the birds. Leave these and other natives standing in fall to feed our feathered friends.