Key Features
Maintenancevery low
Overview
Matthiola bicornis (syn. M. longipetala subsp. bicornis) is a hardy annual in the Brassicaceae family, grown primarily for its intense evening fragrance. Plants grow 12–18 inches (30–45 cm) tall and 6–8 inches (15–20 cm) wide with a slender, upright to somewhat lax habit. Stems are branching, covered in fine grey-green hairs. Leaves are narrow-lanceolate, 2–4 inches (5–10 cm) long, grey-green, with slightly wavy or toothed margins. Flowers are small, four-petalled, 0.5–0.75 inch (12–18 mm) across, in shades of mauve, lilac, pink, or white — visually inconspicuous during the day, when petals remain partially closed and the plant appears wilted. At dusk, the petals open fully and release a powerful sweet, clove-like fragrance that carries 15–20 feet (4.5–6 m) in still air. Fragrance peaks between 8 PM and midnight and fades by morning. Pollinated by nocturnal hawk moths and other night-flying insects. The species is unrelated to common stock (M. incana) despite sharing the genus — M. bicornis is a straggly annual while M. incana is a showy bedding plant. Bloom begins 8–10 weeks from sowing and continues for 4–6 weeks. Susceptible to flea beetles, downy mildew, and clubroot (Plasmodiophora brassicae) — rotate with non-brassica crops.
Native Range
Matthiola bicornis is native to the eastern Mediterranean region, including Greece, Turkey, and southwestern Asia. It occurs on rocky hillsides, disturbed ground, and coastal habitats at low elevations.Suggested Uses
Sown near outdoor seating areas, bedroom windows, and along paths where the evening fragrance can be experienced at close range. Interplant with day-blooming annuals such as Calendula or Nigella to mask the untidy daytime appearance. Effective in containers on balconies and patios — a 6-inch (15 cm) pot holds 3–5 plants. Often broadcast-sown in mixed annual wildflower strips.How to Identify
Appearance
Size & Dimensions
Height1' - 1'6"
Width/Spread6" - 8"
Bloom Information
Flowers open from late June through August, depending on sowing date. Petals remain partially closed and inconspicuous during daylight. At dusk (approximately 7–9 PM depending on season), petals unfurl fully and fragrance is released. Individual plants bloom for 4–6 weeks. Succession sowing every 3 weeks extends the fragrant period from June through September.Detailed Descriptions
Flower Description
Mauve, lilac, pink, or whiteFoliage Description
Grey-greenGrowing 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
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Direct sow seeds on the soil surface in mid to late spring, after the last frost. Seeds are tiny — mix with fine sand for even distribution. Press gently into the soil but do not cover, as light aids germination. Germination takes 7–14 days at 55–65°F (13–18°C). Thin seedlings to 4–6 inches (10–15 cm) apart. Plant in full sun to partial shade in average, well-drained soil with a pH of 6.0–7.5. Water moderately — once established, the species tolerates mild drought. No staking is required, though plants may lean; interplanting with sturdier companions helps. No fertilisation needed in average soil.Pruning
No pruning required. Remove spent plants after bloom declines and replace with a later succession sowing. If self-seeding is desired, allow seed pods to mature and shatter in place — the species self-sows readily in open, disturbed ground.Maintenance Level
very lowContainer Growing
✓ Suitable for container growing
Minimum container size: 1 gallons
⚠️ Toxicity Warning
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
After last frost in mid to late spring; succession sow every 3 weeks
Days to Maturity
56–70 days
Plant Spacing
5 inches
Companion Planting
Avoid Planting With