Matthiola longipetala bicornis (Evening Scented Stock)

For optimal germination rates, initiate seed propagation indoors under controlled conditions—unless the species exhibits a high sensitivity to root disturbance. This approach allows precise regulation of temperature, humidity, and light, improving germination consistency and seedling viability. Do not skip any recommended seed treatments, as they are essential for uniform and successful germination.

Keep soil evenly moist during germination. DO NOT LET IT DRY OUT—once seeds begin absorbing water (imbibition), drying can kill the seed embryo, and even brief dryness after sprouting can kill seedlings.

Seed Treatment:
Soak seeds in warm water for 4–6 hours before sowing to encourage quicker germination
• Seeds are small — sow shallowly or surface sow

When to Sow:
Indoors: Start 4–6 weeks before last frost
Outdoors: Direct sow in early spring or in late summer to early fall in mild climates

Sowing Instructions:
• Sow seeds ⅛ inch (3 mm) deep or surface sow and press lightly into soil
• Use grow lights to maintain 12–16 hours of light per day.
Humidity: Use a humidity dome or clear cover to maintain consistent moisture during  germination. Open the dome BRIEFLY once per day to allow fresh air in and reduce mold risk.  Remove the dome entirely once seedlings emerge.
• Keep soil evenly moist until germination
• Ideal temperature: 15–18°C (59–65°F)
• Germinates in 7–21 days

Watering:
• Water gently and consistently during germination
• Once established, water moderately — avoid overwatering

Spacing:
• Thin or transplant to 6–10 inches (15–25 cm) apart

Growing Tips:
• Blooms open in the evening with a sweet, clove-like fragrance
• Prefers full sun
• Can tolerate light shade, especially in warmer climates
• Prefers well-draining, moderately fertile soil
• Avoid overly rich or wet soils, which can cause leggy growth
• pH range: 6.0–7.5
• Flowers are ideal for scented night gardens
• Use near patios, walkways, or windows where scent can be enjoyed
• Blooms in spring to early summer
• Excellent for containers, beds, and borders
• Best grown as an annual in most climates

More guides at: bloomoutlet.com/seed-guides