Culture
Easily grown in rich, medium moisture, well-drained soils in full sun to part shade. Prefers loose, fertile, somewhat gritty, neutral to slightly alkaline loams with regular and consistent moisture. Add lime to acidic soils to adjust the soil pH. Best flowering performance typically occurs in cool summer climates. Appreciates some afternoon shade in hot summer climates. Deadhead spent flowers to tidy the planting and encourage additional bloom. For growth in warm winter climates (USDA Zones 8-9), seed or starter plants may be planted in spring for bloom throughout summer into fall or planted in fall. Fall planted dianthus usually does not bloom in winter, but the foliage remains green with flowers appearing in early spring. For growth in northern climates, seed or starter plants should be planted at last spring frost date for summer to fall bloom. First flowers begin to bloom about 10-12 weeks after seed is planted.
‘Supra Purple’ is an F1 hybrid. Seed should be purchased from reliable seed distributors. Seeds harvested from garden plants in fall may be planted in the garden the following spring, but the seeds of F1 hybrids usually do not reproduce plants true to the parent cultivar.
Noteworthy Characteristics
Bedding dianthus, often called pinks or carnations, may be Chinese pinks (Dianthus chinensis) or a hybrid of Chinese pinks with sweet William (D. barbatus). When crossed, these two species produce an interspecific hybrid, commonly called hybrid pink, which can be used as a vigorous annual, flowering from seed, with superior performance to both species regarding length of flower production and heat/frost tolerance. These plants can also be quite hardy, and grown as perennials, but are often shorter lived than other dianthus hybrids. Bedding dianthus often have medium green leaves that are wider compared to perennial dianthus cultivars.
Genus name comes from the Greek words dios meaning divine and anthos meaning flower.
The common name of pink for plants in the genus Dianthus is in probable reference to the fringed flower petal margins (they appear to have been cut with pinking shears) and not to flower color.
‘Supra Purple' is a hybrid pink. It is part of the Supra Series. It typically grows in an upright rounded mound to 8-12" tall and to 8-10" wide. Compact, vigorous, strongly branched plants typically form a dense mound of narrow, linear, gray-green, grass-like foliage. ‘Supra Purple’ is noted for its lengthy bloom of 5-petaled rosy pink to purple flowers (each to 1.5” across) with highly fringed petal edges. Flowers bloom on stems rising from the foliage mound to 12” tall. Flowers bloom from late spring (early spring if fall–planted) to late summer (June-September) with continued but somewhat sporadic additional bloom into fall (sometimes to first frost).
‘Supra Purple’ received the AAS Bedding Plant award in 2006.
Problems
Dianthus is generally susceptible to crown rot, particularly if grown in wet, poorly drained soils. Leaf spot may occur in humid summers, particularly where plants are crowded. Watch for wilt and rust. Potential insect pests include slugs, cutworms, aphids, caterpillars, thrips and red spider mites. Deer tend to avoid this plant.
Uses
Rock gardens, border fronts, slopes, edgings, fragrance gardens and outdoor pots/containers. When massed, these mat-forming plants can form an attractive ground cover.