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Dianthus barbatus
sweet William
Europe and western Asia; mountain meadows, rocky slopes, and grasslandsLearn more
Overview
Dianthus barbatus is sweet William, an upright biennial (occasionally short-lived perennial) growing 12-24 inches (30-60 cm) tall and 9-12 inches (23-30 cm) wide. Flat-topped dense terminal flower clusters 3-5 inches (7-13 cm) of small 5-petaled fringed flowers 0.5 inch (1.3 cm) in white, pink, red, salmon, purple, or bicolored with contrasting eye zones in May-July (6 weeks). Lightly clove-scented. Bright to medium green lance-shaped opposite evergreen leaves forming a basal rosette. In Caryophyllaceae. Barbatus = bearded (the fringed petal margins). Native to Europe and western Asia. A classic biennial — forms a foliage rosette in year one, flowers and dies in year two. Self-sows freely if seed heads are left, maintaining a colony without replanting. This biennial lifecycle (no bloom in year one from spring-sown seed) is the primary limitation — stagger sowings for annual bloom. Modern first-year-bloom cultivars ('Dash', 'Jolt') bypass the biennial requirement. Crown rot in wet winter soil. Rust (Puccinia) on foliage in humid conditions. Deer browse. Toxic to cats and dogs. Zones 3-9. Full sun to partial shade. Growth rate is moderate.
Native Range
Native to Europe and western Asia. Found in mountain meadows, rocky slopes, and grasslands.Suggested Uses
Grown in cottage gardens, mixed borders, cutting gardens, and in containers of at least 2 gallons (7.5 L), spaced 9-12 inches (23-30 cm). Cut flower. Biennial — stagger sowings or allow self-sowing. Toxic to pets. Zones 3-9.How to Identify
Appearance
Size & Dimensions
Height1' - 2'
Width/Spread9" - 1'
Reaches mature size in approximately 1 years
Bloom Information
Late spring to early summer (May-July). Flat-topped dense clusters 3-5 inches (7-13 cm) of fringed flowers 0.5 inch (1.3 cm) in white, pink, red, salmon, purple, bicolored. Lightly clove-scented. 6 weeks. Bee- and butterfly-visited. Self-sows freely.Detailed Descriptions
Flower Description
White, pink, red, salmon, purple, or bicolored (often with contrasting eye zones and picotee edges); flat-topped dense terminal clusters (cymes) 3-5 inches (7-13 cm) across of small 5-petaled flowers each 0.5 inch (1.3 cm) with fringed (barbatus = bearded) petal marginsFoliage Description
Bright to medium green, simple, lance-shaped, opposite, 2-4 inches (5-10 cm); forms a low evergreen basal rosette in the first yearGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Full sun to partial shade (4-8 hours). Well-drained soil pH 6.5-7.5 — tolerates alkaline and chalky soil. Biennial — forms a rosette year one, blooms year two (or use first-year cultivars). Self-sows freely. Deadhead to extend bloom or allow self-sowing. Crown rot in wet winter soil. Rust on foliage. Toxic to pets. Zones 3-9.Pruning
Deadhead spent flower clusters to extend bloom. After the plant finishes flowering and sets seed, pull the spent biennial plants and replace with the next generation of seedlings. Allow some seed heads to remain for self-sowing.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Maintenance Level
moderateContainer Growing
✓ Suitable for container growing
Minimum container size: 2 gallons
⚠️ Toxicity Warning
Toxic to petsPlanting Guide
Planting Methods & Timing
Planting Method
both
Indoor Start
8 weeks before last frost
Direct Sow Timing
Direct sow outdoors in late spring to early summer (June-July) for bloom the following year. Seeds germinate in 7-14 days at 65-70°F (18-21°C). Or start indoors 8 weeks before transplanting outdoors in spring for first-year bloom with early-flowering cultivars.
Days to Maturity
120–180 days
Plant Spacing
10 inches