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 that grew in grandma's garden, make room in 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 rebloom into fall possible. Dianthus blooms may be single or double (think little carnations), but all have the same jagged-edged petals.
- Botanical Name: The genus Dianthus belongs to the carnation family, Caryophyllaceae. Dianthus barbatus is a biennial type of dianthus, while D. plumarius, D. superbus, and D. deltoides are perennials in the garden.
- Common Name: Pinks, Dianthus flowers, Cheddar Pink, Sweet William, Clove Pinks, Gillyflower
- Plant Type: Perennial flower
- Mature Size: Plant heights vary from 5 inches to 3 feet tall.
- Sun Exposure: Full Sun
- Soil Type: Rich, well-draining soil
- Soil pH: 6 to 7.5
- Bloom Time: Spring and Late Summer to Fall
- Flower Color: White, lilac, red (but never a hint of orange), and all shades of pink
- Hardiness Zones: 3 through 9
- Native Areas: Europe and Asia, with one species native to North Africa
How to Grow Perennial Dianthus Flower
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 garden beds and borders, where others can appreciate the pleasant clove fragrance. Add some dianthus plants to butterfly and hummingbird gardens, as the flowers attract both with their nectar.
Another option is to include dianthus plants in an 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.
For those puzzled by the common name “pinks,” look at the variety of dianthus colors on the market, and examine the fringed edges of the petals closely. A pair of pinking shears would give a similarly ragged edge as 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.”
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 Fahrenheit.
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.
Try these favorite kinds of dianthus:
- 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: This is a very fragrant heirloom with lilac flowers.