Woolly yarrow (Yellow wooly yarrow) care

Light

Woolly yarrow needs sun on the leaves, not just bright ambient room light. Demands full sun — at least 6 hours of direct sunlight. Poor light causes sparse, open mats that lose the compact woolly character and flower poorly. Ideal for exposed, south-facing slopes and rock gardens. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water woolly yarrow every 2–3 weeks once established; minimal supplemental watering needed. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Among the most drought-tolerant Achillea species. Established plants survive on natural rainfall in temperate climates. Water young plants fortnightly during first summer. Avoid all overwatering — root rot is the main killer.

Soil and pot

Woolly yarrow grows best in very well-drained, lean, sandy or gritty soil. Thrives in poor, sharply drained soils including sand, gravel, and scree. Absolutely intolerant of heavy clay or wet winter soils. pH 6.0–8.0; tolerates alkaline ground well. Adding grit when planting in heavier soils is strongly recommended. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Woolly yarrow sits happiest at around Low (20–45% RH) humidity and -25 to 38°C (-13 to 100°F). Prefers low atmospheric humidity. The dense woolly indumentum on the leaves is an adaptation to dry, open habitats. High humidity or poor drainage will cause crown rot. Excellent in Mediterranean-climate gardens. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed woolly yarrow sparingly. Rarely needed. Lean soils produce the best compact growth. A single light application of balanced granular fertiliser in early spring may benefit plants in very poor substrate, but avoid nitrogen-rich feeds. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on woolly yarrow in the Growli community. Each is annotated with the most common cause so you know where to start.

• Crown rot in winter wet — The chief risk for this species is sitting in cold, wet soil over winter. Plant on a slope or raised bed, improve drainage with coarse grit, and avoid mulching directly over the crown.
• Loss of compact habit — Mats can become open and die out at the centre after several years. Divide clumps every 3–4 years in spring, replanting vigorous outer sections into freshly prepared ground.
• Aphid colonies — New growth in spring can attract aphids. A strong jet of water or insecticidal soap spray controls light infestations; ladybird and lacewing predators usually provide natural regulation.

Propagation

Division in spring is most reliable — separate rooted sections from the mat edge and replant immediately. Stem tip cuttings taken in late spring root in gritty compost. Seed can be surface-sown at 18°C in spring; seedlings are variable. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Woolly yarrow is mildly toxic to pets. As an Achillea species, A. tomentosa contains sesquiterpene lactones and achilleine, which can cause contact dermatitis and gastrointestinal upset in pets and sensitive people. ASPCA lists Achillea millefolium as toxic to dogs, cats, and horses; treat this species with equal caution. The woolly foliage reduces palatability to grazing animals. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Woolly yarrow deep-dive guides

Every aspect of woolly yarrow care, each with its own calibrated guide:

• Woolly yarrow watering schedule
• Woolly yarrow light requirements
• Best soil mix for woolly yarrow
• Woolly yarrow fertilizing guide
• When to repot woolly yarrow
• How to propagate woolly yarrow
• Woolly yarrow growth rate & size
• Woolly yarrow cold hardiness
• Woolly yarrow temperature & humidity
• Is woolly yarrow toxic to cats & dogs?
• Is woolly yarrow toxic to cats?
• Is woolly yarrow toxic to dogs?
• Getting woolly yarrow to bloom

Featured in these plant shortlists

Woolly yarrow qualifies for 4 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Woolly yarrow is also commonly called Woolly yarrow or Yellow wooly yarrow.

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• All 6887 plant care guides in the Growli library