Fernleaf Yarrow
Achillea filipendulinaUSDA | Grow Zone
3-9Outdoors all year in zones 3 to 9. Anywhere colder, keep it as a houseplant. Protect it below 40°F.
- Light
- Full sun, 6-8 hours
- Water
- Deeply, every 1-2 weeks
- Humidity
- Moderate, tolerant of dry
- Temperature
- 60-75°F (15-24°C)
- Difficulty
- Beginner
- Growth
- Moderate
- Mature size
- 2-3 ft tall, 1-2 ft wide
- Pets
- Non-toxic to pets and children
Achillea filipendulina, commonly known as Fernleaf Yarrow, is a perennial plant celebrated for its vibrant yellow flowers and fern-like foliage. Native to Eurasia, it thrives in sunny gardens and attracts pollinators, making it a favorite among gardeners.
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Ideal temperature
60-75°F is where it grows fastest. Below 40°F cold damage starts.
Spacing and harvest
- Mature size
- 2-3 ft tall, 1-2 ft wide
- Plant apart
- 12-24 in
- Frost
- Hardy: survives frost
Everything it needs
9 essentials at a glance
Watering
Achillea filipendulina prefers well-drained soil and should be watered deeply but infrequently.
Water every 1-2 weeks during dry spells, allowing the top inch of soil to dry out between waterings. In the growing season, adjust frequency based on rainfall and temperature. Signs of over-watering include yellowing leaves and root rot, while under-watering may cause wilting and browning leaf edges.
Light
This plant thrives in full sun, requiring at least 6-8 hours of direct sunlight each day.
Ideal placement includes sunny borders or garden beds. While it can tolerate partial shade, insufficient light may lead to leggy growth and reduced flowering.
Soil
Achillea filipendulina prefers sandy or loamy soil with a pH range of 6.0 to 7.0.
It requires excellent drainage to prevent root rot, so consider using a potting mix designed for drought-tolerant plants or adding sand to improve drainage.
Humidity
This plant prefers moderate humidity levels but is quite tolerant of dry conditions.
To increase humidity, mist the leaves or place a humidity tray nearby. Signs of humidity stress include browning leaf tips and wilting.
Temperature
Achillea filipendulina thrives in temperatures between 60-75°F (15-24°C) and is hardy in USDA zones 3-9.
It can tolerate heat but may struggle in extreme cold, so provide mulch in winter to protect the roots.
Fertilizing
Use a balanced fertilizer with an NPK ratio of 10-10-10 during the growing season, applying every 4-6 weeks.
Reduce feeding in late summer and fall. Signs of nutrient deficiency include stunted growth and pale leaves.
Pruning
Prune back spent flowers to encourage new blooms and maintain a tidy appearance.
Use clean, sharp scissors or pruning shears. Deadheading can be done throughout the blooming season to promote further flowering.
Repotting
Repotting is generally not necessary for Achillea filipendulina, as it prefers to be in the ground.
If grown in pots, consider repotting every 2-3 years or when roots become crowded. Signs it needs repotting include roots growing out of the drainage holes and stunted growth.
Propagation
Propagation can be done through seeds or division.
For seeds, sow them indoors 6-8 weeks before the last frost or directly in the garden after frost. For division, carefully dig up established plants in spring or fall and separate the root clumps, replanting them at the same depth.
When it's unhappy
Yellow leaves
Why it happens
Over-watering or poor drainage.
How to fix it
Ensure soil drains well and reduce watering frequency.
Root rot
Why it happens
Excess moisture in the soil.
How to fix it
Improve drainage and allow soil to dry out before watering again.
Leggy growth
Why it happens
Insufficient sunlight.
How to fix it
Move the plant to a sunnier location to encourage compact growth.
Powdery mildew
Why it happens
High humidity and poor air circulation.
How to fix it
Increase air circulation and apply fungicide if necessary.
Pests (aphids, spider mites)
Why it happens
Dry conditions and stress.
How to fix it
Regularly inspect plants, and use insecticidal soap or neem oil to treat infestations.
Care through the year
Spring
In spring, remove any dead foliage from winter and apply a balanced fertilizer to encourage new growth. Check for pests and diseases.
Summer
During summer, ensure consistent watering, especially during dry spells. Deadhead spent flowers to promote continuous blooming.
Fall
In fall, cut back the plant after flowering has finished. Mulch around the base to protect roots during winter.
Winter
In winter, protect the plant with mulch if grown in colder zones. Avoid excessive moisture to prevent root rot.
Toxicity & Safety
Achillea filipendulina is generally considered non-toxic to pets and children. However, ingestion of large quantities may cause mild gastrointestinal upset. Always consult a medical professional if ingestion occurs.
Good to know
Why are my Fernleaf Yarrow leaves turning yellow?
Yellow leaves on Fernleaf Yarrow are often a sign of over-watering or poor drainage. Ensure the soil dries out between waterings and check for root rot.
How often should I water my Achillea filipendulina?
Water your Fernleaf Yarrow every 1-2 weeks, allowing the top inch of soil to dry out between waterings. Adjust frequency based on rainfall and temperature.
What type of soil is best for Fernleaf Yarrow?
Achillea filipendulina thrives in sandy or loamy soil with a pH of 6.0 to 7.0. Ensure excellent drainage to prevent root rot.
How can I propagate my Fernleaf Yarrow?
You can propagate Achillea filipendulina through seeds or division. Sow seeds indoors or directly in the garden, or divide established plants in spring or fall.
What should I do if my Fernleaf Yarrow is leggy?
Leggy growth usually indicates insufficient sunlight. Move your plant to a location where it receives at least 6-8 hours of direct sunlight each day.
Is Fernleaf Yarrow toxic to pets?
Achillea filipendulina is generally non-toxic to pets and children, but ingestion of large quantities may cause mild gastrointestinal upset.
When should I prune my Fernleaf Yarrow?
Prune back spent flowers throughout the blooming season to encourage new blooms and maintain a tidy appearance.
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