2004 - The Year of Dianthus

Dianthus, also known as Sweet William, pinks, maiden pink, gillyflower and carnation, is from the Greek words for "flower of the gods" (meaning Zeus; Jove, or Jupiter, to the Romans). Dianthus is in the family Caryophyllaceae, a name derived from the Greek for clove tree, a reference to the often clove-scented blooms.

Dianthus barbatus (Dye-ANN-thus bar-BAY-tus) is the familiar Sweet William of countless old-fashioned cottage gardens, a short-lived perennial or biennial. Newer varieties are annual flowering. Sweet William does not refer to a person; "sweet" alludes to the plant's fragrance; William comes from the mispronounciation, centuries ago, of the French word for the flower: little eye, or oiellet. The blooms of the species and many hybrids have a central spot, or eye. Hardy to Zone 4 and grows from 5 inches to 2 feet tall. Its single, sometimes double, flowers appear in dense clusters from late spring through summer. Flowers may or may not be fragrant.

Dianthus chinensis (Chin-NEN-sis) a.k.a. China pinks, can be an annual or biennial, though all the best varieties or series on the market today will flower as an annual - first year from seed. Originally from China, plants tend to be dwarf, 6 to 10 inches tall, but may reach 18 inches. They produce single (occasionally double), small, scentless flowers intermittently all summer. These carefree plants need little maintenance; deadheading is not required for them to continue to bloom. The common name, pink, refers not to the color of the blooms but to their serrated edges; when sewing to "pink" meant to cut or notch in old-English--think of pinking shears. Some of the best among open-pollinated varieties are 'Persian Carpet,' 'Pastel Bedder' and 'China Doll'. Hybrids 'Snowfire', 'Magic Charms' and 'Corona Cherry Magic' offer F1 vigor and unusual colors. The blooms of the latter combine solid cherry, lavender with cherry center and tie-dyed lavender/cherry on the same plant for a striking show. 'Raspberry Parfait' reaches a full sun garden height of 6 to 8 inches and spreads 8 to10 inches. Hardy to Zone 5.

You need to go way back in history, to ancient Greek and Roman times in fact, to find the first references to Dianthus. Through the centuries, they traveled from Europe to England and eventually to colonial America, picking up a variety of intriguing names along the way. Known variously as sweet william, pinks, gillyflower, cottage pink, carnation and clove pink, Dianthus species became an integral part of gardens, due to their charming forms, colors and sometimes heady fragrances. People also used the flowers for flavorings, in wine, soups, sauces and jams.

Because Dianthus cross-pollinates between species with ease in the wild and in the garden (like the orchid in that characteristic) connoisseurs had an abundance of different plants to select from. Until the 20th century, however, most selections were chance hybrids, courtesy of nature and of enthusiastic gardeners. The characteristics of a particular plant were usually preserved through propagating by cuttings and division.

Corona Cherry Magic
"Corona Cherry Magic"

Raspberry Parfait
"Raspberry Parfait"

Until the last century, Dianthus flowers had a much shorter season than they now do. In the late 1960s, a Goldsmith Seeds breeder, Charles James, crossed D. barbatus with D. chinensis, in spite of Glenn Goldsmith’s warning that the cross would be unable to produce seed. Happily, he was wrong, and ‘Queen of Hearts,’ as the resulting plant was named, went on to win an All-America Award in 1971. This interspecific cross had many advantages. The chinensis parent line brought large flowers; the barbatus parent, hardiness and vigor. While the parent plant set seed, the progeny F1 hybrid plants were sterile and did not set seed. Because of this, the hybrid plants flowered freely all season.

Dianthus can easily be grown from seed or transplants, in ground beds or in containers. Locate them in full sun, preferably in a garden that receives at least six hours of direct sun daily. Most Dianthus in shady locations produce fewer blooms on lankier plants. Dianthus prefers well-drained, somewhat alkaline soil. Fertilize monthly with a water-soluble plant food, if you did not use a controlled-release fertilizer at planting time. Deadhead spent blooms to encourage reblooming.

Dianthus lends itself to many design uses, depending on height and growth habit. Use dwarf and mat-forming Dianthus as an edging for a border, in containers, in a rock garden, among pavers in a patio, as a groundcover, or along a rock wall. Plant medium to tall varieties with other annuals and perennials in a border, in a cutting garden, or in front of evergreen shrubs. Combine Dianthus with plants that harmonize with its foliage and flower colors: for example, coral bells, feverfew, lamb's-ear, larkspur, lavender, hardy geraniums, petunias, poppies, floribunda and shrub roses, and sage.

Many Dianthus species go to seed and stop producing flowers in midseason. Prior to this time, most Dianthus had a flowering season similar to candytuft, pretty but short.

Goldsmith followed up with another interspecific cross; ‘Magic Charms’ won an AAS award in 1974. Both varieties, but especially ‘Magic Charms,’ opened up the market for growers, who could now produce flowering bedding plants in pots or packs for spring which would go on to bloom all summer for the home gardener. Other interspecific crosses, by many companies, have followed in the ensuing years, some open-pollinated, some F1 hybrids.

When growing Dianthus in the garden, keep these tips in mind:

  • To encourage continuous blooming or reblooming, deadhead (cut off spent blooms) regularly to prevent seed-formation. In a cutting garden, you promote new blooms each time you gather flowers for bouquets--an excellent cut flower, Dianthus lasts up to two weeks in a vase. After the first flush of bloom in late spring/early summer, lightly shear back both spent blooms and foliage of edging and groundcover plants.
  • Many Dianthus self-seed readily, making even the annuals seem like perennials.
  • Dianthus are shallow-rooted, so to insure the survival of the plants over winter, mulch lightly after the ground freezes in fall or early winter. If rabbits are rampant in your area, a mulch or covering of pine boughs may deter them from nibbling on the plants’ leaves, which tend to persist into winter, especially in the South.
  • In the Southeast and Southwest, gardeners can grow most species of Dianthus for flower color through winter. Planting times range from September to November, depending on the area and fall temperatures. Start with plants from a garden center or plan ahead and sow seeds indoors or out.
  • Although pests and diseases are seldom much of an issue for Dianthus, keep an eye out for signs of red spider mites and aphids. Wash the latter off with a hard spray from the garden hose; prevent the former by providing enough space for good air circulation among the plants and, if necessary, treat with an insecticidal soap. (Pesky rabbits may find the blooms and foliage less tasty.) When it comes to diseases, diligence is the best prevention. Plant in soil with good drainage, give plants sufficient spacing for air circulation, and immediately remove any plant parts or plants with signs of disease, such as watery stems (rot) or powdery coating on leaves (mildew).

Source- National Gardening Bureau