Native to the mountains of Europe, sweet William (Dianthus barbatus) bears drifts of old-fashioned flowers, reminiscent of Victorian cottage gardens. One of over 300 species in the Dianthus genus, its relatives are commonly known as pinks and carnations (Dianthus caryophyllus). Typically, pinks grow low to the ground, bloom profusely and smell like cloves and other spices. Their nickname originated, not from their bloom color, but from their fringed, or pinked, petal edges, although many pinks, as well as sweet William, produce flowers in shades of pink or rose.
Most pinks grow as perennials, but sweet William follows a biennial cycle, seed sown one year to bloom the next. A bit more tolerant of cold than others in the family, sweet William flourishes in U.S. Department of Agriculture plant hardiness zones 3 to 9. Generally, Dianthus are recommended for USDA zones 4 to 9. Reputedly, sweet William's short life may be due to its extravagance of blooms. Cutting the plants back can extend their life span to include a second flowering later in the season. Prune perennial pinks' foliage by as much as half after blooming stops. Sweet William often self-seeds, though the developing plants do not always stay true to the parent. But this variability can be fun, resulting in kaleidoscopic color combinations. You never know what might appear the next year.
Besides carnations, cheddar pinks (Dianthus gratianopolitanus) and cottage pinks (Dianthus plumarius) are intensely fragrant with a spicy scent. Older strains of sweet William, however, bear only a mild fragrance, and newer hybrids of the species carry no scent. Florists grow carnations commercially in greenhouses as much for their perfume as for their lush, colorful blooms. Most fragrant of all, hybrids of cottage pinks and carnations, commonly called border pinks, work best at the front of floral borders.
The Dianthus genus features attractive, slender, linear or lance-shaped leaves. Pinks' foliage frequently has a blue or grayish cast, including that of the ground-hugging carpets of the cheddar pink and looser clumps of cottage pinks or Allwood pinks (Dianthus alwoodii). On the other hand, sweet William's flat leaves are light to dark green. Instead of blue or gray highlights, foliage of sweet William may be tinged with maroon.
Unlike some of the ground cover pinks, typically no higher than a foot tall, sweet William is an upright specimen twice that tall. In fact, the Amazon series of sweet William cultivars grows up to 36 inches high. To reach their potential, rock garden types, such as cheddar pinks, require sandy, alkaline soil, but carnations. sweet William and cottage pinks prefer a richer soil. Chinese pinks (Dianthus chinensis) share the most characteristics with sweet William, being erect biennial plants up to 30 inches tall, without scent.
- Fine Gardening Magazine: Pinks - Petite and Prolific
- The Sunset Western Garden Book; Kathleen Norris Brenzel, Editor
- The Garden Primer; Barbara Damrosch
- The Perennial Care Manual; Nancy J. Ondra
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