Woolly yarrow (Achillea tomentosa) is a resilient perennial known for its distinctive appearance and low maintenance. It features silvery, finely textured foliage that forms a soft, mat-like carpet, topped with bright yellow flowers. Originating from southern Europe and western Asia, this hardy species is a popular, durable groundcover due to its drought tolerance and adaptability.
Growing Requirements
Woolly yarrow thrives in ample sunlight, needing six to eight hours of direct sun daily for robust growth and abundant flowering. Insufficient light results in sparse foliage and fewer blooms, diminishing its dense habit.
Well-draining soil is fundamental for woolly yarrow. It tolerates poor to moderately fertile soil; overly rich soil can be detrimental, promoting leggy growth over a compact form. A neutral to slightly alkaline soil pH (6.0-8.0) supports its development.
Young woolly yarrow plants need consistent moisture during establishment. Once mature, they are drought tolerant, preferring drier conditions. Excessive watering can lead to root problems. Water deeply but infrequently, allowing soil to dry between waterings.
Woolly yarrow thrives in USDA hardiness zones 3 through 8. It withstands cold winters and hot, dry summers, making it versatile for many garden landscapes. Selecting the correct hardiness zone ensures the plant’s long-term survival.
Ongoing Care
Maintaining woolly yarrow requires minimal effort. Deadheading spent flower clusters promotes new blooms throughout the season and maintains neatness. Cutting back foliage in late fall or early spring refreshes the plant, stimulating new growth and preventing legginess.
Fertilization is rarely necessary for woolly yarrow, as it thrives in lean soil. Excessive nutrients can lead to weakened stems and reduced flowering, compromising its compact form. Avoid fertilizing this species.
Woolly yarrow clumps may benefit from division every 3-4 years to rejuvenate and prevent overcrowding. This practice helps maintain its vigor and spread. Division is best performed in early spring or fall when the plant is not actively flowering.
Woolly yarrow resists most common garden pests and diseases, making it robust for low-maintenance gardening. However, it can be susceptible to root rot if planted in wet or poorly draining conditions. Proper drainage is the most effective preventative measure.
Landscape Uses
Woolly yarrow excels as a mat-forming groundcover, especially in sunny, dry areas where its dense foliage suppresses weeds. Its low-growing, spreading habit makes it an excellent choice for covering bare soil. Its texture and color add visual interest.
Its preference for lean, well-drained soil and compact growth make woolly yarrow ideal for rock gardens. It blends seamlessly with stones and other drought-tolerant plants, adding a soft, natural look. It is also used in xeriscaping, contributing to water-wise landscapes with minimal irrigation.
Woolly yarrow creates neat edging along garden beds or pathways, providing a defined, uniform border. Its contained spread ensures it does not overwhelm adjacent plantings. For container gardening, it is a suitable choice, provided the container offers excellent drainage to prevent waterlogging.
Beyond its ornamental value, woolly yarrow attracts beneficial insects like bees and butterflies. Its bright flowers serve as a reliable nectar source, contributing to local biodiversity.