The Perennial Dianthus Flower

Dianthus Flowers
Photo: Mint Images/Getty Images

It’s easy to get confused when shopping for dianthus plants for the garden, as the genus encompasses plants that behave as annuals, perennials, and biennials. While each of these has their place in the flower garden, if you’re looking for the heirloom pinks your grandmother grew, you should make room in your landscape for the perennial dianthus flower.

Get to Know Dianthus

The genus Dianthus belongs to the carnation familyCaryophyllaceae.

Dianthus barbatus is a biennial type of dianthus, while D. plumarius, D. superbus, and D. deltoides are perennials in the garden.

If you’re puzzled by the common name “pinks” when you look at the variety of dianthus colors on the market, examine the fringed edges of the petals closely. A pair of pinking shears would give you a similarly ragged edge on a piece of cloth, hence the nickname. The name “cheddar” refers to the Cheddar Gorge in England where pinks have naturalized. In addition to Cheddar pinks, dianthus also goes by the common names of clove pinks, gillyflower, and sweet William (which most often refers to the biennial dianthus). 

Kate Middleton did not corner the market on choosing clever flowers for her bridal bouquet when she added the blooms of Sweet William to her arrangement. The name doesn’t derive from the prince, or any other man named William; rather, it is a derivative of the French word that means “little eye.”

Dianthus Attributes

Many Dianthus plants feature handsome bluish-grey foliage that is showy in its own right when the plants are not in bloom. The foliage is narrow, even grass-like. Plants may exhibit a mounded shape, an erect habit, or a trailing habit. Blooms are heaviest in the spring, with some rebloom into fall possible.

Dianthus blooms may be single or double (think little carnations), but all have the same jagged-edged petals. Flower colors include white, lilac, red (but never a hint of orange), and all shades of pink. Plant heights vary from five inches to three feet tall.

Dianthus Planting Tips

Dianthus flowers may be perennials in zones 3-9, although hardiness varies between varieties. Full sun is important for thriving plants, so choose a location that gets at least six hours each day.

Stem rot can be a problem in dianthus plants if the soil doesn’t drain well. If your soil is heavy clay, consider containers or raised beds for your plants. Dianthus plants like neutral to slightly alkaline soil pH. If your soil pH is below 7.0, correct the acidity with an application of dolomitic limestone. Fireplace ashes can also increase the soil alkalinity. Mulch is fine to keep weeds under control, but to avoid rot don’t let the mulch crowd around the crowns of dianthus.

Dianthus Care

Deadhead dianthus after flowering to promote rebloom.

 Dianthus plants are light feeders, and a shovelful of compost worked into the soil once a year is enough to nourish the plants. Even the perennial dianthus varieties are short-lived in the garden. Save seeds from your favorites to plant the following season where old plants fail to come up.

Garden Design With Dianthus

The mounding shape of dianthus plants and long blooming time makes them welcome additions to the container garden. Place dianthus plants at the front of your garden beds and borders where you can appreciate the pleasant clove fragrance. Add some dianthus plants to your butterfly and hummingbird gardens, as the flowers attract both with their nectar.

Include dianthus plants in your alpine or rock garden. The plants thrive in the quickly draining soil of these landscapes. Choose heirloom varieties of dianthus for your cottage garden. Try the ‘Pheasant’s Eye,’ variety from the 17th century. Dianthus is a safe bet for gardens bothered by deer, as it is a deer-resistant plant. Unfortunately, the same doesn’t hold true for rabbits. Plant some dianthus in your cutting garden. They add fragrance to petite arrangements like nosegays and tussy-mussies.

Recommended Dianthus Varieties

  • Arctic Fire: Features the contrasting eye common in the biennial varieties, but this one is hardy to zone 3.
  • Firewitch: Although this hot pink variety has been in cultivation since 1957, its popularity exploded when it was named the 2006 Perennial Plant of the Year.
  • First Love: Repeat blooms are common on this plant, which may have white and pink blossoms at the same time.
  • Rose De Mai: Very fragrant heirloom with lilac flowers