The National Garden Bureau states that the popularity of carnations (dianthus) is partially because they are so easy to grow and also because of the wide range of their blooming colors. Carnations can be grown as perennials, biennials, or as annual flowers. They lend themselves to many garden design uses, depending on their height and color. Some varieties can be used as a ground cover and other varieties are popular in window boxes. Carnation's gray-green foliage combines well with plants such as coral bells and larkspur.
Carnation has 2,000 years of known cultivation history, beginning in Europe and Asia. Carnations were used as ceremonial crown garlands in Greek times. The word dianthus means "flower of the gods." There are over 300 species of carnation but only four that are generally available for home gardeners. They are Sweet Williams, China pinks, hybrid crosses of these two species, and interspecific hybrids.
Carnations are classified as a perennial herb. They have gray-green leaves, flowers with five petals, and grow 10 to 20 inches in height. Flowers bloom in shades of red, pink, white and yellow. As with most herbs, carnations thrive in soil that has low to moderate fertility. Over-fertilizing produces leaf growth at the expense of flower growth. Carnations grow well in a garden spot that receive four to five hours of sunlight per day.
Time Frame for Growth
Carnations can be grown from seed or small purchased plants. They can also be propagated by root cutting when plants are mature. Seeds are sown 1/8 inch deep in light, porous soil and spaced 10 to 12 inches apart. When the soil is kept moist, carnation seeds germinate in seven to 10 days for annual varieties, two to three weeks for perennials.
Until the 20th century, hybrid forms of carnation were accidental by either nature or home gardeners. They had a much shorter growing season than carnations known today. Queen of Hearts was the first hybrid interspecific cross breed, created in the late 1960s by Charles James. As a result of this flower hybrid, carnations now had hardiness, vigor, larger flowers and a longer growing season. Many interspecific hybrids followed, and the nursery market for carnations was created.
Benefits and Uses
Growing carnations brings a wonderful, spicy smell to the garden. People are often reminded of a grandmother's flower garden when they smell carnations. Carnations are traditionally a flower given in recognition of an achievement or an important occasion. It is the most common flower given on Mother's Day as a symbol of the pure love mothers have for their children. In Spain, carnations are the national flower, and in Ohio they are the state flower.
Carnations grow in many garden conditions. The Sweet William dianthus is winter hardy to USDA zone 4 and China pinks are hardy to zone 7. Sweet William grows to a height of 5 inches and is a favorite in rock gardens. Taller varieties such as Amazon grow to 24 inches and are good perennial cut flowers. Another modern hybrid is known as a cottage pink and it is low-growing, loosely tufted perennial that has fragrant leaves and flowers.