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 its place in the flower garden, if you're looking for the heirloom pinks that grew in grandma's garden, make room in your landscaping for the perennial dianthus flower.
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 possible rebloom into fall. Dianthus blooms may be single or double (think little carnations), but all have the same jagged-edged petals.
|Botanical Name||D. plumarius, D. superbus, D. deltoides|
|Common Name||Dianthus flowers, pinks, garden pinks, cheddar pinks, sweet William, clove pinks, gillyflower|
|Plant Type||Perennial flower|
|Mature Size||5 inches to 3 feet tall, depending on variety|
|Sun Exposure||Full sun|
|Soil Type||Rich, well-draining soil|
|Soil pH||Neutral to slightly alkaline|
|Bloom Time||Spring, late summer to fall|
|Flower Color||White, lilac, red, pink|
|Native Areas||Europe, Asia, Africa|
How to Grow Perennial Dianthus Flowers
Most dianthus flowers are easy to grow and can thrive in a range of conditions. They bloom best when given plenty of sun, but they don't like the high heat of mid-summer. Deadheading and some cutting back after the first bloom help to ensure a second bloom later in summer or early in the fall.
Full sun is important for thriving plants, so choose a location that gets at least six hours of light each day. It's best to plan them early in the spring season. They will then be established before the hot summer weather.
Stem rot can be a problem in dianthus plants if the soil doesn’t drain well. If the soil is heavy clay, consider containers or raised beds for 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 flowers need weekly watering. Try one inch of water once a week. Avoid water-logging the soil.
Temperature and Humidity
These plants can tolerate a light frost but don't like a deep freeze. It is possible for some hardier plants to survive outdoors in the winter. Try a frost blanket if temperatures remain below 40 degrees Fahrenheit. The flowers can also go dormant in consistently hot summer temperatures, above 85 degrees F
Dianthus plants are light feeders. A shovelful of compost worked into the soil once a year is enough to nourish the plants. Deadhead dianthus after flowering to promote rebloom.
Propagating Dianthus Flowers
Even the perennial dianthus varieties are short-lived in the garden. Save seeds from favorites to plant the following season where old plants fail to come up.
Varieties of Perennial Dianthus
- Arctic Fire: This dianthus features the contrasting eye common in the biennial varieties, but it 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: This is a very fragrant heirloom with lilac flowers.
Landscape Uses for Perennial Dianthus
The mounding shape and long blooming time of dianthus plants make them welcome additions to the container garden. In garden beds, place dianthus at the front and along borders so you can appreciate their pleasant clove fragrance. Or, add some dianthus plants to a butterfly and hummingbird garden, as the flowers attract both with their nectar.
Another option is to include dianthus in an alpine or rock garden, where they thrive in the fast-draining soil. For a cottage garden, choose heirloom varieties of dianthus, such as the Pheasant’s Eye variety from the 17th century. Dianthus also are ideal for a cutting garden. They add fragrance to petite arrangements like nosegays and tussy mussies.
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.
When choosing varieties of dianthus for your landscape, don't be confused by the name “pinks.” While many varieties do have pink flowers, this nickname comes from the fringed edges of the flower petals. A pair of pinking shears would give a similarly ragged edge as on a piece of cloth.
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.”