How to Care for Yarrow

Yarrow (Achillea millefolium) is a hardy, drought-tolerant perennial with soft, feathery foliage and flat-topped clusters of tiny flowers held on wiry stems. It is a mainstay of sunny borders, pollinator gardens, and low-water plantings, asking for little more than sun and sharp drainage.

Light

Grow yarrow in full sun, at least six hours daily, for sturdy, upright stems and the heaviest bloom. In too much shade the plant flops, stretches, and flowers poorly, and it becomes more prone to disease. The more sun it gets, the more self-supporting and floriferous it stays.

Water

Yarrow is highly drought tolerant once established. Water young plants regularly through their first season to build roots, then scale back sharply; established clumps rarely need supplemental water except in prolonged drought. It strongly prefers dry conditions and resents wet feet, so let the soil dry between any waterings. Overwatering causes floppy, lax growth and encourages rot.

Soil & Potting

Average to lean, well-drained soil is ideal, and yarrow actually performs best in poor soil. Rich, fertile ground produces soft, weak stems that flop. It tolerates sandy and rocky soils and a wide pH range. The single most important requirement is good drainage.

Humidity & Temperature

Yarrow is very cold hardy and thrives across a broad range of climates. It prefers warm, dry air and good airflow; humid, still conditions can invite powdery mildew. It handles heat well and is a strong choice for hot, exposed sites.

Feeding

Do not fertilize. Yarrow prefers lean conditions, and feeding promotes floppy, weak growth at the expense of flowers. Skip amendments entirely in most soils.

Propagation

Divide established clumps every 2-3 years in spring or fall to keep them vigorous, replanting the healthy outer sections. It also grows readily from seed sown in spring, and basal cuttings root easily. Division is the most reliable way to keep named color forms true.

Repotting / Pruning

Deadhead spent flower clusters to encourage a second flush of bloom and keep the plant tidy. Cut the whole plant back after flowering to refresh the foliage. In late fall or early spring, cut old stems to the ground. Yarrow spreads by rhizomes and can be vigorous, so lift and divide to control its spread.

Common Problems & Pests

Yarrow is largely trouble-free. The main issues stem from too much water or shade: powdery mildew, rust, and stem rot in damp, crowded conditions, and floppy stems in rich soil or low light. Improve airflow, cut back on water, and stake or divide crowded clumps. Pests are rare, though aphids may appear on tender new growth.

Seasonal Care Tips

Plant in spring or fall. Water new plantings through the first summer, then let them fend for themselves. Deadhead and shear back after the main bloom for a repeat show. Cut the plant down in late fall or leave the seed heads for winter interest, then divide overgrown clumps in early spring.