Allium aflatunense hollandicum | Ornamental Onion

Seed Treatment (Cold Stratification Required)

How to Stratify:

  1. Moisten a small amount of vermiculite, sand, or peat moss (just damp, not wet).
  2. Mix seeds with the moist medium in a resealable plastic bag.
  3. Place in the refrigerator at 35–40°F (1–4°C) for 6–8 weeks.
  4. Check occasionally to ensure medium remains moist and free of mold.
  5. After stratification, sow seeds immediately.

Sowing Instructions

  1. When to Sow:
    • Indoors: Start seeds in late winter to early spring after stratification.
    • Outdoors: Sow in fall for natural cold stratification.

  2. Soil Requirements:
    • Use well-draining, sandy or loamy soil.
    • Avoid waterlogged conditions.
    • Ideal pH: 6.0–7.5 (neutral to slightly acidic/alkaline).

  3. Light Requirements:
    • Prefers full sun (6–8 hours daily) for best flower production.

  4. Sowing Depth:
    • Sow seeds ¼ inch (6 mm) deep.
    • Lightly cover with fine soil and gently firm down.

  5. Watering:
    • Keep the soil evenly moist but not soggy during germination.
    • Once established, Allium plants are drought-tolerant and require minimal watering.

  6. Germination Time:
    • Germination can take 30–90 days or longer — patience is key.
    • Ideal temperature post-stratification: 60–70°F (15–21°C).

  7. Spacing & Transplanting:
    • Once seedlings have several true leaves, transplant to individual pots or garden beds.
    • Final spacing: 8–12 inches (20–30 cm) apart.

Growing Tips

  • Allium aflatunense hollandicum produces globe-shaped purple flower heads on tall, upright stems — perfect for cut flowers and pollinator gardens.
  • Leaves may yellow as the plant blooms — this is normal.
  • Deer- and rodent-resistant, and attracts bees and butterflies.
  • Blooms in late spring to early summer.
  • Allow seed heads to dry on the plant for decorative interest or seed collection.

Add architectural beauty and bold color to your garden with this stunning, low-maintenance ornamental onion!