AUBRIETA CULTORUM aka A. HYBRIDA (Rock Cress)
Cold Stratification (Pre-treatment Required):
To break dormancy and encourage better germination, cold stratify seeds for 2–4 weeks before sowing.
How to Cold Stratify Aubrieta Seeds:
- Moisten a paper towel or small amount of vermiculite/perlite—just damp, not soaked.
- Place the seeds on the damp medium and fold gently.
- Insert into a labeled, resealable plastic bag or airtight container.
- Store in the refrigerator (not freezer) at 4–5°C (39–41°F) for 2–4 weeks.
- Check weekly: If seedlings sprout in the fridge, remove them gently and plant immediately.
- After stratification, remove seeds and sow immediately.
When to Sow
- Indoors: Start 6–8 weeks before the last frost.
- Outdoors: Sow in late spring to early summer, once the soil has warmed.
Soil & Location
- Prefers well-drained, alkaline to neutral soil (pH 6.5–7.5).
- Amend heavy soils with grit or coarse sand to improve drainage.
- Needs full sun for the best flowering display.
Sowing Instructions
- Do not cover seeds—light is essential for germination.
- Press seeds gently onto the surface of moist soil.
- Spacing: Thin or transplant seedlings 15–30 cm (6–12 in) apart.
Watering & Germination
- Keep soil moist but not soggy.
- Use a fine mist spray to avoid washing seeds away.
- Germination time: 14–21 days at 18–21°C (65–70°F)
Transplanting & Care
- Move seedlings outdoors after the last frost once hardened off.
- Water sparingly—Aubrieta becomes drought-tolerant once mature.
- Trim lightly after flowering to keep the plant compact and vigorous.
Long-Term Beauty
Aubrieta returns year after year with bright cascades of color. Excellent for slopes, containers, stone walls, and sunny borders.