Achillea Millefolium Cassis

Achillea Millefolium Cassis 

Achillea millefolium ‘Cassis’ is a striking flowering perennial admired for its rich cherry-red flowers, delicate fern-like foliage, and upright growth habit. Its clusters of small, white-centred, deep cherry-red flowers create a bold display from summer into autumn, adding vibrant colour and texture to garden borders, cottage gardens, and mixed perennial beds. As the flowers mature, their colour may soften, creating subtle variations that add depth and interest to the garden.
yarrow ‘Cassis’

Highly valued by gardeners and cut-flower growers, ‘Cassis’ is an excellent choice for adding dramatic colour to ornamental gardens and floral arrangements. Its flat-topped flower clusters are held on sturdy, branching stems above attractive green foliage, creating a natural, relaxed appearance. The rich red blooms contrast beautifully with white flowers, purple salvias, blue veronicas, and ornamental grasses, making this variety a versatile addition to a wide range of planting schemes. Its flowers can also be used in fresh bouquets and dried arrangements, bringing a distinctive splash of colour to floral displays.
NC State Extension

Thriving in full sun and well-drained soil, Achillea ‘Cassis’ is a hardy, relatively low-maintenance perennial that tolerates dry conditions once established. It grows well in a range of soil types, including sandy and moderately fertile soils, provided excess water drains freely. Regular watering during establishment encourages healthy root development, while moderate watering thereafter helps maintain vigorous growth. Removing faded flower heads can encourage further flowering and keep the plant looking neat throughout the growing season.
yarrow ‘Cassis’

Growing to approximately 45–75 cm in height, ‘Cassis’ forms an attractive clump of finely divided foliage with upright flowering stems. It is well suited to sunny perennial borders, mass plantings, cutting gardens, and naturalistic landscapes. Its deep red flowers provide a beautiful contrast against lighter-coloured plants, while the delicate foliage adds softness and texture. Allow sufficient space for the plant to develop, as yarrow can spread gradually through its roots.
yarrow ‘Cassis’

Easy to grow and rewarding throughout the warmer months, Achillea ‘Cassis’ is an excellent choice for gardeners seeking bold colour, attractive foliage, and reliable seasonal interest. Whether planted in groups for a dramatic display or combined with softer pastel flowers in a mixed border, its rich cherry-red blooms bring warmth, character, and natural beauty to outdoor spaces.

Plant Features

• Botanical Name: Achillea millefolium ‘Cassis’

• Common Name: Yarrow

• Flower Colour: Deep cherry red with small white centres

• Mature Height: Approximately 45–75 cm

• Mature Spread: Approximately 45–60 cm

• Growth Habit: Upright, clump-forming perennial

• Flowering Season: Summer into autumn, depending on local growing conditions

• Light Requirements: Full sun

• Soil Requirements: Well-drained soil

• Water Requirements: Low to moderate once established

• Garden Uses: Borders, mass plantings, cottage gardens, and cutting gardens

• Special Features: Rich flower colour, drought tolerance once established, and suitability for fresh and dried flower arrangements

Why You’ll Love It

• Deep cherry-red flowers create a bold and colourful garden display.

• Delicate, fern-like foliage adds texture and visual interest.

• Long flowering season provides colour throughout the warmer months.

• Excellent cut flower for fresh bouquets and dried arrangements.

• Attracts butterflies and other beneficial pollinators.

• Drought tolerant once established, making it suitable for water-wise gardens.

• Combines beautifully with white, pink, purple, and blue flowering plants.

• Upright stems provide structure and height in perennial borders.

• Ideal for cottage gardens, naturalistic landscapes, and contemporary planting schemes.

• Relatively low maintenance and easy to grow in sunny positions.

Growing Tips

Light: Plant in full sun to encourage strong growth and abundant flowering. A sunny position with at least six hours of direct sunlight daily is ideal.

Soil: Grow in well-drained soil. Achillea tolerates a range of soil types, including sandy and relatively poor soils, but does not perform well in persistently waterlogged conditions.

Watering: Water regularly while the plant establishes. Once established, it tolerates dry periods and generally requires less frequent watering. Avoid overwatering, particularly in heavy soils.

Spacing: Allow approximately 30–45 cm between plants, adjusting the spacing according to the desired planting density and growing conditions.

Feeding: Apply compost or a light, balanced fertiliser in spring if necessary. Avoid excessive feeding, as overly rich soil may encourage weak growth.

Deadheading: Remove faded flower heads to maintain a tidy appearance and encourage further flowering.

Pruning: Cut back spent flowering stems after blooming to encourage fresh growth and maintain a neat shape. Remove old foliage in late winter or early spring.

Dividing: Divide established clumps in spring or autumn where conditions are suitable to maintain plant vigour and manage spreading.

Support: The stems are generally sturdy, but plants growing in exposed or windy positions may benefit from light support.

Cut Flowers: Harvest flower stems when most of the flower clusters are open. For dried arrangements, hang the stems in a dry, well-ventilated space away from direct sunlight to help preserve their colour.