How to Deadhead Flowers for More Blooms All Season

Why Deadheading Brings More Flowers

To deadhead, remove each faded flower together with its stalk, cutting or pinching back to just above the next bud or leaf on the stem. Do it as soon as the flower looks scruffy. The Royal Horticultural Society suggests daily for summer bedding plants and once a week or every other week for border perennials. Removing the old flower stops the plant from forming seed, and many annuals, perennials and repeat-flowering roses answer with new buds.

The Royal Horticultural Society gives the reason plainly: deadheading directs energy into stronger growth and more flowers instead of seed pods. It also keeps heavy-petaled flowers such as peonies from scattering old petals, and it prevents self-seeding in plants that spread readily that way.

How much it helps depends on the plant. University of Illinois Extension describes deadheading as a way to encourage a longer bloom time in certain species, and the plant lists further down show which ones.

Where to Make the Cut

The position of the cut depends on what is below the flower. A Penn State Extension Master Gardener brochure gives three cases. If new flower buds are present, cut to the topmost one. If the flower is on a leafy stem, cut to a leaf. If it stands on a bare stalk, cut to the basal rosette, the cluster of leaves at the base of the plant.

University of New Hampshire Extension reduces this to one habit for perennials: cut spent flowers back to a lateral bud or leaf. On peonies and irises it adds that a cut placed low enough is hidden by the foliage.

Spikes and heads carrying many flowers need two passes. For delphiniums and lupins, the Royal Horticultural Society advises pinching or trimming off single flowers where practical, then pruning the entire head to just above a lower bud, leaf or side shoot once all the flowers have finished.

Tools follow the stem. Soft growth can be pinched or snapped off between finger and thumb. For thick, tough or stringy stems the Royal Horticultural Society recommends secateurs, scissors or a knife. Our guide to choosing pruning shears covers which type suits which stem.

Annuals and Bedding Plants

Annuals complete their life in one season, so they are the group that needs the most frequent attention, daily at the height of summer by the Royal Horticultural Society’s guide. The Penn State brochure lists annuals worth deadheading, among them cosmos, geranium, marigold, nasturtium, pansy, petunia, snapdragon, verbena and zinnia.

Most of these can be done by hand. Petunias, pansies and heliotrope are pinched off with the flower stalk. Pelargoniums, the bedding plants usually sold as geraniums, take two steps: pinch off individual flowers, then cut the whole cluster and its long stalk down to just above where it joins the main stem.

Three common annuals need no deadheading at all. Fibrous begonia, impatiens and moss rose drop their own spent flowers, according to the Penn State brochure. The Royal Horticultural Society adds fuchsias, bedding lobelias and salvias, which either set little seed or shed their flowers neatly. The two sources part ways here, since the Penn State brochure keeps lobelia and salvia on its list of annuals to deadhead and suggests pruning back lobelia’s long stems in midsummer.

Perennials, Plant by Plant

Perennials vary more than annuals, so it pays to know each one.

Plant	What to do	Source
Shasta daisy	Cut back to a lateral flower bud; it produces more flowers	New Hampshire
Dianthus	Shear all stems down to the basal foliage; new flowers often follow within a few weeks	New Hampshire
Campanula, garden phlox	Deadhead to a lateral bud or leaf	New Hampshire
Coreopsis	Shear the mass of spent flowers	Penn State
Delphinium, lupin	Prune the whole head to a lower bud, leaf or side shoot	Royal Horticultural Society
Hardy geranium, catmint, lady’s mantle	Cut back close to ground level after flowering for a second flush	Royal Horticultural Society
Peony	Clip the stem back to a strong leaf	New Hampshire
Iris	Cut the whole flowering stalk as low as possible	New Hampshire
Daffodils and other large bulbs	Remove the flower behind the seed capsule and leave the green stalk	Royal Horticultural Society

University of Illinois Extension lists butterfly weed, coreopsis, scarlet bee balm, garden phlox and Culver’s root among perennials that bloom longer when deadheaded. Daylilies are deadheaded for looks: the Penn State brochure lists them “for appearance”, and New Hampshire says that while the plants are in full bloom all you need to do is snap off the spent flower heads.

Go carefully with shears. Illinois cautions that cutting back more than half of the foliage can put a plant under stress. For planting ideas that need little of this work, see the list of low-maintenance perennials, and tired clumps that flower poorly may need dividing more than deadheading.

Roses

Roses have their own rule, based on the leaves. Iowa State University Extension advises that on an established rose the stem may be cut back to a 5-leaflet leaf, keeping at least two 5-leaflet leaves on each shoot. Make the cut about 1/4 inch above the leaf, parallel to the angle of the leaf.

First-year roses get a lighter touch. Once all the flowers in a cluster have died, remove them above the uppermost 3-leaflet leaf.

The Royal Horticultural Society describes a quicker method for hybrid teas: snap the faded flower off, breaking the stalk just below the head. For other roses it advises snipping individual flowers or clusters down to just above the next leaf.

Plants to Leave Alone

Some flowers are worth more as seed heads. The Royal Horticultural Society advises against deadheading rudbeckias, cornflowers and sunflowers, whose seed feeds birds, and species and rambler roses, which carry decorative hips. Love-in-a-mist and honesty are grown partly for their ornamental seed heads.

The Penn State brochure names perennials to leave standing through winter: aster, astilbe, common yarrow, coneflower, liatris, oriental poppy, rudbeckia and sedum. Sources differ on purple coneflower. Illinois lists it among plants that flower longer with deadheading, so a workable middle path is to deadhead early flushes and leave the last one.

When to Stop for the Season

For most flowers, deadheading runs from early spring until a killing frost, as the Penn State brochure puts it. Roses are the exception.

Iowa State University Extension advises gardeners in Iowa to stop deadheading hybrid tea, grandiflora and floribunda roses in late summer, in late August or September. The spent flowers then develop into hips. Hip development slows the plant’s growth and helps prepare it for winter.