The scientific name of the carnation is Dianthus caryophyllus; they are said to be the plants of the gods. Di translates to "of Zeus" and anthus means "flower," together forming Dianthus. Another derivative is the word corone, which means "floral garland," and transitions into carnation. There are a variety of Dianthus types -- carnation, or caryophyllus, is one.
The Dianthus caryophyllus is the most common of the types of carnation or dianthus. The foliage exhibits a greyish-green appearance. Flowers come in pink, white, red or salmon colours. The carnation does well in humid conditions under light to full sun in well-drained soil. Carnations grow from 4 to 24 inches tall and are hardy to U.S. Department of Agriculture Plant Hardiness Zones 3 and 4.
The scientific name for sweet william is Dianthus barbatus. This carnation type has a 300-plus-year history. Available in a variety of colours, sweet william is a biennial plant that can act as a short-lived perennial. A biennial grows the first year and blooms the second. Because it easily reseeds itself, it mimics a perennial. Height of the barbatus reaches 18 to 24 inches.
Hardy Annual Dianthus
Dianthus chinensis, or the hardy annual dianthus variety, bloom from spring to fall in red, pink or white. The chinensis does not adapt well to hot, humid climates and prefers an alkaline soil. The Dianthus chinensis is classified as a perennial for Zones 6 or 7, but acts more like an annual in the lower USDA Zones.
Referred to as just "pink," the Dianthus plumarius at only 4 inches is shorter than other carnation types. Consequently, it make a good border and container plant and works well in a rock garden. Deadheading encourages more blooms, which are a pleasant soft pink.
Maiden pinks, or Dianthus deltoides, is started easily from seed and often used as ground cover. Deltoides are short-lived perennials that grow low to the ground. The flowers are red or pink and bloom through the summer. The tiny rubies is a common variety of deltoides that blooms bright red.