Zones for the Dianthus Carnation

Features

• Depending on the cultivar, dianthus can range in size from petite 6-inch plants suitable for edging to 36-inch specimens appropriate for use as cuttings and as backdrops in gardens and ornamental plantings. According to the University of Vermont Extension, dianthus falls into the category of half-hardy annuals that are able to tolerate light frost. In warm weather climates, dianthus can even overwinter and behave as perennials. Blossoms can be single or double and may appear in shades of pink, crimson, red, lavender and white. Dianthus carnations are sometimes referred to as "pinks," a name that is derived not from their color but from the distinctive frilled edges of their blossoms, making them appear to have been trimmed with pinking shears.

Hardiness Zones

• Most dianthus cultivars thrive in climate zones 4 through 8; depending on the variety, some can grow in zones 3, 9 and 10. Climate zones are calibrated according to the average low wintertime temperatures that occur in each location. In zone 4 -- which includes parts of New York and Maine, as well as northern states in the Midwest and West -- winter temperatures don't routinely drop beneath 20 degrees Fahrenheit below zero. Zone 4 is the northernmost cutoff point for many dianthus carnations, while most experts declare zone 9 -- located in parts of Florida, Texas, Arizona and California -- to be the southern border of the area in which most dianthus cultivars will thrive.

Care Tips

• Dianthus needs six hours of full sun a day and does best in fertile, well-drained, slightly alkaline soil. According to Cornell University, dianthus carnations require adequate air circulation at their base and should not be mulched. Feed dianthus carnations every six to eight weeks during the growing season with an all-purpose liquid fertilizer. By removing spent blossoms, you can trigger a second burst of blooming in the fall. Avoid overwatering; dianthus is susceptible to fungal root rot, which is indicated by yellowing and wilting foliage.

Cultivars

• The Dianthus barbatus, also called Sweet Williams, can grow to 24 inches tall. Featuring long, graceful stems and fragrant flowers, Sweet Williams is ideal for cutting and displaying. According to "Flower & Garden" magazine, Sweet Williams does its best flowering in its second year and is hardy in zones 3 through 9. China pinks, or Dianthus chinensis, are smaller and particularly suited to container growing. They are hardy in zones 2 through 9. Dianthus plumarius, a perennial cultivar, forms into grassy clumps, giving the plant a pleasing, tousled appearance. According to Cornell University, many varieties of dianthus plumarius are hardy in zones 4 to 10; a few types, however, can't be grown north of zone 5, while other robust specimens can flourish even in zone 3. Consult the planting guide that comes with the dianthus to be sure.