Flowers

How to Grow Yarrow: Planting, Spacing, Care & Bloom

Quick answer

Start indoors 6 to 8 weeks before last frost (Mississippi State). Transplant after frost danger passes. Divide crowns every 2 to 3 years (MSU/Clemson). NC State: spreads aggressively; wear gloves for contact dermatitis; keep pets from grazing.

Yarrow at a glance

PlantStart indoors: 8–6 wk before last frost; Transplant: last frost
SunFull sun; well-drained; drought tolerant once established (MSU/NC).
SpacingMSU: space 9–18 inches in row; rows 18–36 inches.
Days to bloomEarly summer–fall bloom (NC)
-9-8-7-6-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Updated

Safety: NC State: “Avoid planting where your pets are and wear gloves to prevent contact dermatitis.” Tags: problem for cats, dogs, and horses; contact dermatitis. Leaves/flowers bitter; edible raw/cooked in moderation if used at all. Not medical or veterinary advice. (NC State Achillea millefolium)

Yarrow (Achillea millefolium) — common / cottage yarrow.

Yarrow flowers
Yarrow (Achillea millefolium). Photo: Petar Milošević, Wikimedia Commons, CC BY-SA 4.0 (resized).

Sourced from university extension guides. For dates where you live, use the ZIP planting planner.

Planting timing

Mississippi State: “Seeds are commonly started indoors 6–8 weeks before the last frost date… The transplants may be planted outdoors after frost danger passes.” Light aids germination; 65–72°F; emerge about 10–14 days. Divide crowns every 2–3 years. (Mississippi State cottage yarrow) Clemson: divide every 2 or 3 years; spring or fall. (Clemson dividing perennials) Planner: Start indoors last frost −8 to −6; Transplant last frost 0.

Depth and spacing

MSU: space 9–18 inches in row; rows 18–36 inches. Height typically 18–36 inches. NC: height 1–3 ft; width 1–~4 ft; space 12 inches–3 feet. Surface sow / light cover.

Sun, soil and water

Full sun; well-drained; drought tolerant once established (MSU/NC). Wet soils invite crown/root disease. NC: spreads aggressively by rhizomes and seed.

Care

Deadhead to prolong bloom and reduce seed spread (NC). Divide when the center dies out (Clemson). Avoid excess fertility — soft weak stems (MSU).

Bloom

Early to mid-summer into fall (NC). Useful as a cut or dried flower (MSU).

Pests and diseases

MSU: aphids, mealybugs, thrips, spittlebugs; powdery mildew and root/stem rots if wet — prefer drip, not overhead. Contain aggressive spread (NC).

Related: ZIP planner · organic pest control

Frequently asked questions

When do I start yarrow?

6 to 8 weeks before last frost indoors; transplant after frost (Mississippi State).

Will it take over?

It can spread aggressively — divide and deadhead (NC/Clemson).

Is it safe around pets?

NC State: avoid planting where pets graze; wear gloves for contact dermatitis.

Sources