How to Plant and Grow Dianthus

Dianthus is the quintessential cottage garden flower. Also called "pinks," these plants are treasured for their grasslike, blue-green foliage and abundant starry flowers that are often spicily fragrant. Dianthus varieties range from tiny creeping groundcovers to 30-inch tall cut flowers, which are a favorite among florists. Some have large blotches of deep red, while others feature rings of color on the edges of their petals. Many flaunt double blossoms, and some have flowers clustered at the stalk's tip, giving them the look of a mini bouquet.

The meaning of the “pink” moniker is two-fold: The flowers are often pink (though they come in other colors, too), and the edges of the petals have a fringed look, as if someone trimmed them with pinking shears. The blossoms of some varieties, like Dianthus superbus, feature a very long, exaggerated fringe, like streamers flying off each petal.

Before you start planting, be aware that some varieties of dianthus aren't safe for pets. Dianthus caryophyllus, better known as carnations, are toxic to dogs, cats, and horses. Dianthus deltoides, or maiden pinks, are also toxic to these animals. The leaves are also mildly toxic to humans if eaten and can cause contact dermatitis if touched.

Where to Plant Dianthus

When planting dianthus, look for a location with full sun—ideally, one that enjoys at least six hours of sunlight per day. If that's not an option, partial shade is suitable, too. Note that in overly shady spots, mat-forming types may begin to rot, and taller varieties, like carnations, need lots of light to stay standing upright. (Some towering types may still need additional support.)

Dianthus needs very well-drained soil. Mat-forming varieties are very susceptible to rot in wet/humid climates, so planting them on a 2- to 3-inch mound can help keep water off the crown. Depending on which type you choose, dianthus works well as a border plant, in containers or rock gardens, or en masse in garden beds.

How and When to Plant Dianthus

The cooler months of spring and fall are the ideal time for planting. Space dianthus about 6 to 18 inches apart, depending on the type; dig a hole roughly twice the size of the root ball. If you spread mulch, opt for a thin layer, since air circulation is essential to the health of the stem.

Dianthus Care Tips

Dianthus requires minimal to moderate care. Although it's prone to fungal root rot, you can avoid this issue with well-drained soil and appropriate watering.

Light

Full sun—at least six hours per day—is ideal for dianthus, but it will also tolerate partial shade. Although the type commonly known as carnations dislikes heat, the flowers still need ample sunlight to help them stand tall. This can make them a poor candidate for southern gardens.

Soil and Water

Well-drained soil is the key to avoiding the root rot that can plague these plants. In fact, dianthus won't tolerate overly wet soil—occasionally dry is better than too moist. Neutral to slightly alkaline soil is best, but a little acidity is also acceptable. Dianthus can handle clay, silt, or sandy soil.

Don't water your dianthus if the soil is still moist. Wait until it's dry, since overwatering can cause the leaves to turn yellow. Too much moisture also increases the odds of root rot.

Temperature and Humidity

These cool-season plants, ideally planted in spring and fall, can withstand a light frost. However, dianthus may begin to exhibit signs of stress below about 40°F. Most varieties won't thrive in hot, humid conditions and stop blooming once the temperature rises in summer.

Fertilizer

To encourage dianthus to keep blooming, feed it a balanced fertilizer every six to eight weeks during the growing season. Fertilizer isn't essential for keeping dianthus alive, especially if you add a little compost around the plants from time to time.

Pruning

Dianthus plants come in all shapes and sizes, so pruning needs will vary. Miniature varieties form a tight little lump of foliage and blooms, while giant species have almost no basal foliage. Mat-forming perennial varieties feature very tight-knit spreads of foliage, and as they grow, you may notice dead spots in the center of the foliage. When this occurs, divide the plant and re-plant it to encourage new growth. Remove any old, dead foliage throughout the season.

Removing old blossoms on all types of dianthus encourages another round of blooming. Make sure you know whether the plant is a true perennial or a biennial before you start deadheading. For biennial varieties, blooming is a sign they've reached their final year. But if you leave some of the spent flowers on the plant, they will seed your garden to produce plants next year.

At the end of the season, you can leave the foliage of your dianthus behind for winter interest. Alternatively, trim the plants back, leaving 1 to 2 inches above the soil line.

Pests and Problems

Pests attracted to dianthus include aphids, grasshoppers, slugs, snails, and sow bugs.

Overwatering and inadequate air circulation can lead to root rot and other fungal diseases in dianthus. One such disease is rust, which causes orange, gold, or brown-red spots on leaves; fortunately, this is mostly a cosmetic concern that can be resolved by establishing healthy growing conditions.

How to Propagate Dianthus

Many dianthus species are short-lived, lasting just a few years. However, you can keep your garden populated through propagation. Plant seeds outdoors in early spring when there's still a chance of frost. Cover with a thin layer of soil, so light can still reach the seeds. This is the easiest way to propagate dianthus, but keep in mind that the new plants will not be exactly the same as the original.

In order to reproduce the exact plants in your garden, use stem cuttings. Harvest them after your dianthus has flowered, from late June to early July. If the plant looks dry, give it a thorough drink the day before you take the cuttings. Look for a node on the stem, then cut about ¼ inch below it at a 45-degree angle. Make sure the cutting includes four or five sets of leaves; remove the pair closest to the node.

Dip the stem into water, then into rooting hormone, and insert it into a container of moist potting soil, using a pencil to pre-poke a hole for the cutting. Place it in a well-lit spot without direct sunlight. Make sure the medium remains moist. The cutting should take root within about 3 to 4 weeks. When new growth appears, you can transplant the cutting to your desired location.

Types of Dianthus

Fruit Punch 'Apple Slice' Dianthus

This perennial cultivar features double red blossoms with light pink accents, poking up from a mound of blue-green foliage. It reaches 10 inches tall and 12 inches wide.

'Arctic Fire' Maiden Pinks

Dianthus deltoides 'Arctic Fire' is a mat-forming plant that's great as a groundcover. Dark green foliage contrasts with white flowers featuring a pink eye ringed in red. The flowers close partway in the evening.

China Pink

Dianthus chinensis is most often grown as a cool-season annual flower. However, it can also be a short-lived perennial in Zones 5 and warmer. The dramatically fringed flowers come in a variety of colors for a pretty pop along borders or in containers.

'Firewitch' Cheddar Pinks

Dianthus gratianopolitanus 'Firewitch' entices with its fringed, clove-scented magenta blossoms. The biggest bloom occurs in mid-spring to early summer, but blooming may happen sporadically in late summer and fall. This cultivar is hardy in Zones 3–8 and grows just 6 inches tall.

'Grans' Favorite' Border Pinks

'Grans' Favorite' is an old-fashioned scented variety with miniature pink blossoms edged in raspberry red. The double flowers resemble carnations.

Hardy Carnation

Dianthus caryophyllus, or carnations, have been used as cut flowers for 2,000 years and are still favored by florists. Hardy in Zones 8–10, these plants produce sprays of spicily scented blooms, which aren't as potent as they once were, since the scent has been bred away. With stems 18 to 30 inches long, carnations may need staking in the garden.

'Ideal Violet' Hybrid Dianthus

'Ideal Violet' is bred for cold-weather resistance and heat tolerance in the summer. This hybrid makes an excellent cool-season annual or short-lived perennial, flaunting fragrant red-violet blossoms on 10- to 12-inch tall plants.

'La Bourboule Pink' Cheddar Pinks

Dianthus gratianopolitanus 'La Bourboule Pink' forms a compact mound of blue-green foliage no more than an inch or two tall. Magenta pink flowers rise several inches above the greenery in mid to late spring.

'Red Maiden' Maiden Pinks

Dianthus deltoides 'Red Maiden' catches the eye with hot pink blossoms that appear in late spring. The 12-inch-tall flowers sit atop a mat of deep green foliage. This cultivar is hardy in Zones 3–8.

'Rose de Mai' Border Pinks

Dianthus plumarius 'Rose de Mai,' also sometimes called gillyflower, is an old-fashioned variety with pale pink blossoms. The highly fragrant flowers appear in mid-spring to early summer. This plant is hardy in Zones 4–10.

'Sooty' Sweet William

Dianthus barbatus nigrescens 'Sooty' brings visual variety with its unique maroon-tinged foliage and dark red flowers. The fragrant cultivar makes a great addition to a cutting garden.

'Spotty' Cheddar Pinks

Dianthus gratianopolitanus 'Spotty' is named for its charming dark pink flowers, spotted with light pink. The sweetly fragrant blossoms attract butterflies.

Sweet William

Dianthus barbatus is a biennial or short-lived perennial. This beauty makes a great addition to cottage gardens with its 2-foot-tall clusters of fragrant red, pink, white, or bicolor blossoms. The flowers often feature eye-catching patterns or circles of many colors. Allow your Sweet William to self-seed in the garden to ensure its return the following year.

Dianthus Companion Plants

Geranium

One of the longest bloomers in the garden, the hardy geranium bears little flowers for months at a time. The jewel-tone, saucer-shape blossoms sit above mounds of handsome lobed foliage. Tough and reliable, geraniums need full sun and can thrive in a wide range of soils. Many of the best varieties are hybrids.

Coralbells

Exciting new varieties with incredible foliage patterns have put coralbells (Heuchera) on the map. Though they used to be sought out only for their spires of dainty reddish flowers, coralbells are now also beloved for the unusual mottling and veining of their leaves. The low clumps of long-stemmed evergreen or semi-evergreen lobed foliage make coralbells excellent groundcover plants. They enjoy humus-rich, moisture-retaining soil.

Iris

Irises, named for the Greek goddess of the rainbow, come in multiple colors and many heights. Whatever hue or size, all irises feature intricate flowers consisting of three upright "standard" petals and three drooping "fall" petals, often in different colors. Some cultivars show off with a second bloom in late summer.

Garden Plans for Dianthus

Small-Space Spring Garden

With this garden plan, you don't need much space to create a fabulous springtime display. Irises anchor the colorful design, while seven Sweet William dianthus contribute dainty detail.

Easy Slope Garden Plan

This mix of easy annuals and tough perennials will beautify any slope. Six 'Bath's Pink' dianthus contribute to the cottage garden vibes of this design.

Lush Garden Plan to Soften a Fence

The vibrant plants in this design provide long-lasting color, fragrance, and texture to hide an unsightly fence. A trio of pretty 'Bath's Pink' dianthus flank one side of the garden.