The following piece was written by Master Gardener Margaret Wolf, who has received training through Colorado State University Extension’s Master Gardener program and is a Master Gardener volunteer for Larimer County.
Sweet, spicy scent
The sweet, spicy scent of Dianthus, combined with their lovely blossoms, has made these plants a favorite among gardeners. All members of the Dianthus family are called “pinks”, from the Latin word pinct, which means pinked or scalloped, referring to the jagged edges of the flower petals. Common hardy plants of this group are known by numerous other names including carnation and gillyflower. These plants are native mostly to Europe and Asia.
Dianthus can be annuals, biennials and perennials. More than 300 species and hundreds of hybrid varieties exist. Although Dianthus varies from two inches to three feet tall, most garden varieties are 10 to 20 inches tall. Most produce richly fragrant flowers in the spring or summer, sometimes blooming until the first frost. Dianthus flowers have five petals and come in a variety of colors including all shades of white, pink, yellow and red, with a huge variety of flower shapes and markings. The leaves are often glaucous grey-green or blue-green. There are multiple perennial species hardy to northern Colorado.
Most Dianthus, depending on height, can be used in the border of a garden and in an area well suited for rock gardens. Dianthus plants should be planted where they will receive at least 6 hours of full sun each day. Avoid over-watering because the foliage can turn the yellow and root-rotting diseases can occur. Plant Dianthus 12 to 18 inches apart –the crown must be level with the surface of the soil. Dianthus should not be mulched because good air circulation around the stems is needed.
For continued blooming, feed these flowers lightly every six to eight weeks with an all purpose liquid fertilizer. Deadheading plants after blooming can encourage re-blooming. Unfortunately, many species are short lived, and propagation every two-to- three years is required to keep plants vigorous. Although fairly care-free, Dianthus species are not immune to disease and insects, but proper garden maintenance can help reduce or eliminate these problems.
Dianthus species have been extensively bred and hybridized to produce many thousands of cultivars for garden use and floristry:
• Allwood Alpinus Group (D. x allwoodii): hardy to zones 4-8, 12-20” tall, various color flowers in summer; gray foliage; flower with varying degrees of spicy fragrance. Cultivars include ‘Becky Robinson’, ‘Doris’, ’Mars’, and ‘Mrs.Sinkins’.
• Sweet William (D. barbatus): hardy to zones 3-8, 10-18” tall, various color flowers in clusters in late spring, green foliage, a biennial but self sows readily. Cultivars include ‘Double Midget’ and ‘Double Tall’.
• Maiden Pinks (D. deltoides): hardy to zones 3-8, 6-12” tall, red to rose flowers in summer, green foliage, forms loose mats of groundcover rapidly. Cultivars include ‘Albus’, ‘Brilliant’, ‘Leuchtfunk’ (Flashing Light), ‘Maiden Pink’, ‘Vampire’, and ‘Zing Rose’.
• Cheddar Pinks (D. gratianopolitanus): hardy to zones 3-8, 9-12” tall, rose to pink solitary flowers in spring, gray foliage. Cultivars include ‘Bath’s Pink’, ‘Feuerhexe’ (Fire Witch), ‘Petite’, and ‘Tiny Rubies’.
• Hairy Garden Pink (D. knappii): hardy to zones 3-7, 15-24” tall, pale yellow flowers in clusters in summer, green foliage, short-lived but reseeds readily.
• Cottage or Grass Pinks (D. plumarius): hardy to zones 3-8, 18-24” tall, various flower colors in early summer with green foliage.
• Bulgarian Pink (D. simulans): hardy to zones 3-7, 3” tall, deep rose/purple sparse flowers in spring, tight bluish-green clumps; considered an alpine plant.
CSU Extension in Larimer County
CSU Extension in Larimer County is a county-based outreach of Colorado State University Extension that provides information you can trust to deal with current issues in agriculture, horticulture, nutrition and food safety, 4-H, small acreage, money management and parenting. For more information about CSU Extension in Larimer County, call (970) 498-6000 or visit www.larimer.org/ext.
Additional gardening information
Looking for additional gardening information? Check out the CSU Extension Horticulture Agent blog at www.csuhort.blogspot.com for timely updates about gardening around the state.
Visit PlantTalk Colorado for fast answers to your gardening questions at www.ext.colostate.edu/ptlk. PlantTalk is cooperation between Colorado State University Extension, GreenCo and Denver Botanic Gardens.