Yarrow: How to sow, grow, and care for Achillea millefolium

Achillea millefolium, commonly called yarrow, is a flowering plant in the family Asteraceae. Other common names include old man's pepper, devil's nettle, sanguinary, milfoil, soldier's woundwort, and thousand seal. A perennial to rediscover, it is native to temperate regions of the Northern Hemisphere in Asia, Europe, and North America.

This plant is easy-to-grow plant and generally maintenance-free. It is exceptionally heat and drought-resistant and grows happily as a perennial bedding plant. These flowers love sunny conditions and will bloom their first year.

With its more carpet-like growth habit, it makes a great ground cover, forming tall, feathery clumps with aromatic, grayish-green, sharply-cut leaves.

The Basics

Height at maturity: 60-75 cm
Width at maturity: 60 cm
Light needs: Full sun to partial shade
Hardiness: As low as -15°C
Type of soil: Well draining
Soil pH: neutral
Pests and disease: Powdery mildew is common, so are aphids
Where to plant: Lawns, flowerbeds, rock gardens and borders
Features: Great for biodiversity and pollinators! Several types of birds, including the common starling, use yarrow to line their nests. It is also a great source of food for pollinators.
Pruning: Pinch off any dead foliage; remove old flowers to encourage new blooms
Flowering period: July-September

Starting your Seeds

You can either direct seed your yarrow in the fall, later spring, or early summer, or you can sow them in a greenhouse in seed cells 8-10 weeks before planting out. Cover seeds with a thin layer of vermiculite to retain moisture and hold seeds in place.

Bottom water or mist lightly to avoid moving the seeds. 3-5 weeks at 55-65°F (13-18°C) in full light are ideal conditions for seedling development. Harden off seedlings and transplant outdoors.

Time to germinate: 10-14 days
Germination temperature: 17-20°C (65-72°F)
Best time to plant: March-April, September-October
Reasonable time to plant: February-April, August-November
Plant spacing: 30-60 cm (12-24 in)
Harvest when pollen is visible on the flowers. Hang to dry.