What is the best way to deadhead perennials?

A Question of the Week
Deadheading iris

Deadheading is a task that most gardeners are aware of, and some, like myself, greatly enjoy. While not absolutely necessary, deadheading does have benefits to both plants and the garden. From an aesthetic perspective, deadheading perennials gives the garden a cleaner, more polished look. In terms of plant health, removing seeds before they develop encourages plants to direct more energy towards root and shoot development. In some special cases, deadheading can even encourage a second bloom later in the season. How to do it properly is determined by a plant’s growth habit and your own preferences.

Deadheading perennials isn’t difficult, only time consuming. Although deadheading is specific to each type of plant, all you really need to learn is to cut spent flowers back to a lateral bud or leaf. Only some plants will re-bloom after deadheading, but most will be better for it regardless.

Daylilies

Deadheading daylillies
Deadheading daylillies

Deadheading daylilies isn’t absolutely necessary, but it does greatly improve the look of the plants. Spent daylily flowers are rather unappealing. After they fade, they quickly turn to mush, occasionally drying onto undeveloped buds, preventing them from fully opening. Flowers that are successfully pollinated eventually form seed pods. When plants are in full bloom, all you need to do is snap off the spent flower heads and seed pods with your fingers. Once there are no longer any blooms, flower stalks can be cut to the base with hand pruners.

Iris

When Iris are done blooming, they usually form a seed pod or two at the apex of their flowering stalks. Unless removed, the seeds will continue to develop until the pods eventually split open. Rather than remove just the seed pods, cut the entire flowering stalk as low as possible until it is hidden by the foliage. Removing a leaf or two that is attached to the flowering stalk will not do any harm to the plant and will make it look a little tidier.

Peonies

Peony flowers quickly fall apart once they’ve finished blooming. Either let the petals fall to the ground or deadhead before they “shatter.” Clip the flower stem back to a strong leaf where the cut will be hidden by foliage. Deadheading won’t stimulate new growth, but it will strengthen plants and improve bloom the following season.

Shasta daisies

Shasta daisies are a perennial that will react to deadheading by producing more flowers. The second bloom is usually less substantial than the first but is still worth striving for. When Shasta daisy blooms are spent, cut them back to a lateral flower bud. When there are no longer any flower buds or the foliage starts to look messy, cut the flowering stalk at the base. Campanula and garden phlox, among others, can be treated in the same way.

Dianthus

Dianthus usually puts on an impressive show all at once in early summer. Most of the flowers open around the same time and senesce in coordination. Though it is possible to clip each individual flowering stem, a more efficient method is to shear all of the stems down to the basal foliage. Regular hand pruners will work, or if you have a lot of plants, hedge shears will make quick work of the job. Dianthus responds very well to deadheading and will often send up a flush of new flowers within a few weeks.

Naturally, there are many more perennials that require deadheading than the ones listed in this article, but the same general principles apply. As long as you remember to cut spent flowers back to a bud or strong leaf, your perennials will do just fine.


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