Achillea filipendulina (Fernleaf Yarrow)

Seed Treatment:

COLD STRATIFY: 1–2 weeks at 4°C (39°F). Store in a damp paper towel or damp sand in the refrigerator. ? If seedlings sprout in the fridge, remove them gently and plant immediately.
• Seeds are very fine and should be surface sown.
• Optionally, soak in room-temperature water for 6–12 hours to improve moisture absorption.
• Do not cover the seeds with soil — they need light to germinate.

When to Sow:

Indoors (Recommended for earlier blooms):

  • Late winter to early spring:  Start seeds 6–8 weeks before your last frost date.

Outdoors (Direct sowing): 

  • Spring: After the danger of frost has passed
  • Fall (mild climates only): September–October
    Fall sowing can help natural stratification and early sprouting in spring.

Sowing Instructions:

• Use a fine, well-draining seed-starting mix.
• Gently press seeds into the surface of moist soil — do not bury.
• Cover trays with a humidity dome or plastic wrap to maintain moisture.
• Maintain a temperature of 18–22°C / 65–72°F.
Typical germination time: 10–14 days
Maximum germination time: up to 35 days, especially if temperatures fluctuate or moisture is inconsistent.

Light Requirements:

• Prefers full sun for best flowering and compact growth.
• Seedlings also need bright light — use a sunny windowsill or grow light indoors.

Soil Requirements:

• Tolerates poor, sandy, or dry soil but prefers well-draining, average garden soil.
• pH range: 5.5–7.5

Watering:

• Keep the soil lightly moist during germination.
• Once established, drought-tolerant — water only during prolonged dry spells.

Spacing & Transplanting:

• Transplant when seedlings have at least 2–3 sets of true leaves.
• Space plants 18–24 inches (45–60 cm) apart.

Growing Tips:

• Produces large, flat clusters of bright yellow flowers and attractive fern-like foliage.
• Blooms in mid to late summer.
• Great for cut flowers, borders, and pollinator gardens.
• Deadhead spent blooms to extend flowering.
• Hardy in USDA Zones 3–9.
• May self-seed mildly if not deadheaded.