How-to Guide
How to Grow Yarrow
The short answer
Common yarrow (Achillea millefolium) is hardy in USDA zones 3a-9b and wants full sun (6+ hours) and well-drained soil; NC State Extension calls it poor-soil and drought tolerant, moderately salt tolerant, and resistant to heat, humidity, and dry conditions. Plants grow 1-3 feet tall and wide with ferny aromatic foliage and flat flower heads.
The catch: it can spread aggressively by rhizomes and seeds. Deadhead flowers to prolong blooming and minimize spread by seed, and divide regularly — yarrow is easily divided — to keep clumps in bounds. Rich, moist soil makes it floppier and more invasive, so lean soil is a feature, not a problem.
Site and soil
Full sun keeps yarrow compact and upright; it is partial-shade tolerant but stretches there. Any well-drained loam or sandy soil around neutral pH suits it, and occasional dry spells are no problem. The plant's weak point is wet ground: root rot develops in too-wet soils, and stem rot or powdery mildew, while rare, follow the same conditions.
Planting and dividing
Plant in spring, allowing 1-3 feet per plant. Division and seed are the recommended propagation methods, and NC State Extension notes plants are easily divided: lift a clump, pull or cut it into rooted sections, and replant only as much as you want — division doubles as containment.
Because yarrow runs by rhizomes, plan to divide every few years both to rejuvenate the center of the clump and to pull the colony back to its allotted space.
Deadheading and spread control
- 1Deadhead after each flush — Deadheading prolongs blooming and minimizes spread by seed — the two reasons to do it, in one cut.
- 2Edge the colony — Slice down around the clump's perimeter with a spade each spring and remove rhizomes that have run beyond bounds.
- 3Divide to reset — Every few years, lift and replant a fist-sized division and compost the rest of an overgrown patch.
⚠ NC State Extension flags yarrow for pets and skin: avoid planting where your pets roam, and wear gloves to prevent contact dermatitis when handling it. If a pet ingests yarrow, check ASPCA/Extension guidance.
Common problems
- Aggressive spreading by rhizomes and self-sown seed — the top complaint.
- Root rot in wet soils; stem rot and powdery mildew are rare.
- Flopping in rich soil or part shade; lean soil and full sun keep stems sturdy.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- North Carolina Extension Gardener Plant Toolbox — Achillea millefolium (Common Yarrow) — Zones 3a-9b; full sun, part-shade tolerant; well-drained soil; poor-soil and drought tolerant, moderately salt tolerant; spreads aggressively by rhizomes and seeds; deadhead to prolong bloom and minimize seed spread; easily divided; root rot in wet soil; contact dermatitis and pet caution