Let’s face it: Even the name of this task sounds scary. But deadheading flowers isn’t as morbid as it sounds; it just means trimming off spent blooms from your plants. This helps keep your garden looking tidy and encourages your plants to continue making new flowers instead of spending energy producing seeds.
Some gardeners get a little nervous about snipping parts off their plants, but unless you start whacking away, it’s tough to damage or kill a plant just by clipping spent flowers. So when your plants have fading blooms or look unattractive, you can pull out your garden shears and start deadheading flowers.
You can often get a clue about which plants to deadhead and which to leave alone just by watching them. If the flowers stay on the plant and become brown and unattractive, feel free to start trimming spent flowers to clean up the mess.
These include Coreopsis, feverfew, golden marguerites, Lobelia, sweet alyssum, smaller mums, Potentilla, flax, Aster, Gaillardia, and Ageratum. Trimming one flower at a time would be too time-consuming, so instead, use grass shears ($28, The Home Depot) to tackle the task in sections. When deadheading flowers on these plants, get as much of the flower stalk as possible. Avoid buds, but don’t worry about taking a little foliage off with the spent flowers; it’ll grow back.
These include large marigolds, summer phlox, Astilbe, peonies, purple coneflowers, black-eyed Susans, daisies, annual and perennial Salvia, petunias, and zinnias. With pruning shears ($38, The Home Depot), also known as secateurs or pruning snips, the key to deadheading flowers is to cut off each spent bloom individually, getting enough of the stalk, so it doesn’t stick out awkwardly. It’s OK (and in the case of leggy plants, such as petunias, desirable) to take off a bit of the foliage, too.
Not to be confused with pruning, deadheading roses means taking out only the minimum amount of stem to remove the spent flower. Cut at a 45-degree angle sloping down toward the center of the rosebush. You should cut on a spot after the first pair of leaves and directly above an outward-facing stem (a stem that points away from the plant’s center).
These include daylilies, larkspur, foxgloves, hostas, tulips, daffodils, Oriental poppies, peonies, and irises. Cut back each spent flower with hand pruning shears as close as possible to where the stalk meets the leaves.
Though many plants will benefit from deadheading, not all need it to bloom. You can also find self-cleaning varieties of some plants that traditionally need deadheading; the spent flowers will naturally fall off, and the plant will produce more flowers without any trimming from you.
Deadheading is just one way to stretch the bloom season; there are other tricks you can use to make the color last.