Aubrieta cultorum (Rock Cress)

AUBRIETA CULTORUM aka A. HYBRIDA (Rock Cress)

Cold Stratification: Cold stratify seeds for 2–4 weeks before sowing.

How to Cold Stratify Aubrieta Seeds:

  1. Moisten a paper towel or small amount of vermiculite/perlite—just damp, not soaked.
  2. Place the seeds on the damp medium and fold gently.
  3. Insert into a labeled, resealable plastic bag or airtight container.
  4. Store in the refrigerator (not freezer) at 4–5°C (39–41°F) for 2–4 weeks.
  5. Check weekly: If seedlings sprout in the fridge, remove them gently and plant immediately.
  6. After stratification, remove seeds and sow immediately.

When to Sow

  • Indoors: Start 6–8 weeks before the last frost.
  • Outdoors (spring-summer): Sow in late spring to early summer after stratification, once the soil has warmed.
  • Outdoors (fall): In mild climates, seeds can also be sown directly in fall. Cold winter conditions act as natural stratification and encourage spring germination. Choose a well-drained spot and avoid waterlogged soil.
  • If winters are harsh (deep freezes with little snow cover), consider mulching lightly or opting for late winter or early spring sowing instead.

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.
  • Requires 12–16 hours of light per day (use grow lights)
  • 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: 14–28 days at 18–21°C (65–70°F) AFTER stratification

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.

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