Carnation (Dianthus caryophyllus): History, Characteristics & Cultivation

Carnation (Dianthus caryophyllus), also known as the clove pink or the pink, is a species of flowering plant in the family Caryophyllaceae, native to the Mediterranean region. The carnation is a herbaceous perennial plant growing up to 80 cm tall. It is native to the Mediterranean region, but its exact natural range is uncertain due to extensive cultivation over the last 2,000 years. They’re among the world’s oldest cultivated flowers.

The original natural flower color is bright pinkish-purple, but cultivars of other colors, including red, pink, yellow, white, and green have been developed. While sometimes dyed blue for cut bouquets, there are no known carnation cultivars that produce a true blue flower. There also are bi-color varieties with petal edges of a different color.

According to the University of Vermont, carnation flowers were used in garlands by the ancient Greeks and Romans. The botanical name Dianthus translates as “flower of the gods.” Carnations were grown in Europe for centuries both for decoration and as a flavoring agent for beer, wine and liquors. The blooms are edible. The first carnations in the U.S. came in a shipment from France to Long Island, New York, in 1852.

In 1907 Anna Jarvis of Philadelphia selected the pink carnation as the symbol for Mother’s Day. In Europe the carnation was formerly used as a treatment for fevers. It was also used to spice wine and ale during Elizabethan times, as a substitute for the more expensive clove (Syzygium aromaticum).

Carnations usually feature beautiful colors, delicate fringed petals, and enchanting fragrance. The scent of carnations is often described as spicy, clove-like, or reminiscent of a combination of cinnamon and nutmeg, this even explains why it was given the nickname “clove pink”. Carnations are the second most popular commercially grown flower in the world, after roses. They are commonly used in the florist trade because of the many colors and because they are among the longer-lived flowers when cut.

Carnations are the official state flower of Ohio and the national flower of Spain and Slovenia. The colors of carnation flowers have specific meanings. Pink flowering plants express motherly love and are a staple in Mother’s Day bouquets. Light red expresses admiration while dark red symbolizes deep love. White blossoms express devotion and wishes for good luck while yellow expresses disappointment and purple shows capriciousness. 

Many carnation varieties are grown commercially in Colorado, southern California, Israel, Kenya and Spain. They can be grown as an annual or perennial garden flower throughout the continental U.S. Most carnation varieties are propagated from seeds or from cuttings taken from the suckers at the base of the plant, from side shoots or from the main stem before flower buds show. 

Carnations thrive in USDA hardiness zones 5 to 9. In general, carnations prefer daytime temperatures between 50 and 70 degrees Fahrenheit. In colder climates, carnations may be grown as annuals or in flowerpots and taken indoors when winter arrives.

Characteristics of Carnations

• Size: Plant: 1-3 feet tall, Flowers: 2-3 inches in diameter
• Growth Rate: Moderate
• Growth Form: Herbaceous perennial (may be grown as annual in some climates)
• Leaves: The leaves are glaucous greyish green to blue-green, slender, up to 15 cm long.
• Stem: Single, upright stem with smooth texture
• Flower: The flowers are produced singly or up to five together in a cyme; they are 3–5 cm diameter, and sweetly scented; the original natural flower color is bright pinkish-purple, but cultivars of other colors, including red, white, yellow and green, have been developed.
• Lifespan: Perennial (may be treated as annual depending on climate)
• USDA Zones: 8-11 (perennial), 7 and below (annual)
• Toxicity: Mildly toxic, can cause irritation if ingested (keep away from pets and children)
• Water: Moderate watering, well-drained soil is crucial to avoid root rot
• Soil: Prefers fertile, well-draining soil with good sun exposure.

Varieties of Carnations

Cultivation of Carnations

• Soil and Sun Requirements: They thrive in well-drained soil with a neutral to slightly alkaline pH (around 6.0 to 7.0). They prefer full sun, requiring at least 6 hours of direct sunlight daily. However, in hot climates, they appreciate some afternoon shade.
• Planting: Plant flower seeds indoors 8-10 weeks before the last frost date for early blooms. Sow seeds 1/8 inch deep in a fine-textured potting mix. Keep the soil moist until seedlings emerge, then thin them to 10-12 inches apart. For outdoor planting, wait until the soil temperature reaches at least 55°F (13°C).
• Watering: Carnations require consistent moisture, but they don’t like wet feet. Water them deeply once a week, ensuring the soil is moist but not waterlogged. In hot and dry climates, you may need to water more frequently.
• Fertilizing: Fertilize every 6-8 weeks during the growing season (spring to autumn). Use a balanced, water-soluble fertilizer (e.g., 10-10-10) for general feeding. Supplement with compost or organic matter to enrich the soil.
• Deadheading: Regularly deadhead spent blooms to encourage continuous flowering throughout the season. This will also prevent the plant from setting seed, which can shorten its flowering period.
• Supporting: Tall varieties may need support to keep the stems upright. Use stakes or a support cage to prevent the stems from bending or breaking under the weight of the flowers.
• Pests and Diseases: Carnations are relatively pest-free, but they can be susceptible to aphids, thrips, and spider mites. Regularly inspect your plants and treat any infestations promptly with insecticidal soap or neem oil. Diseases such as botrytis and fusarium wilt can also affect carnations. Ensure good air circulation and avoid overhead watering to prevent these issues.
• Overwintering: In colder climates, carnations may need protection during winter. Cut back the foliage to 2 inches above the soil and cover the plant with a thick layer of mulch. In warmer climates, carnations can be grown as perennials, but they may become woody and less productive over time.