Achillea millefolium Petra

The Achillea or hybrid yarrow 'Petra' is a recent German creation with a compact habit, whose flowering does not fade over time. It starts off as a pinkish-red colour and matures into raspberry red. From June to September, countless small red flowers with pink centres appear in flat clusters. It is a sturdy and resistant perennial plant, deciduous or semi-evergreen, with light, feathery, matte silver-green foliage that remains intensely fragrant even when dried. Exuberant and undemanding, this plant, commonly found in cottage gardens, brings a lot of colour to sunny borders, edges, and dried or fresh bouquets. It is a nectar-rich plant that is easy to grow in all regions, in not too dry soil.

The 'Petra' hybrid yarrow is a perennial plant with evergreen leaves, spreading through stolons, and has an upright tufted habit from spring onwards. It belongs to the Asteraceae family. It is one of the many hybrids derived from Achillea millefolium, native to Europe and Asia Minor. The plant reaches a height of 60 cm (24in) when in bloom, with foliage measuring 15 to 20 cm (6 to 8in). It spreads over 50 cm (20in) or more.

The inflorescence is a flat cluster. The remarkably long flowering period extends from June to September. The flowers are actually heads, with tubular and pink disc florets, while the peripheral florets are ligulate and pinkish-red when in bloom, turning a more purplish hue and ultimately becoming raspberry red. These heads, which appear at the tops of the stems, form flat or slightly domed clusters, measuring 5 to 7 cm (2 to 3in) in diameter. The foliage is deciduous or semi-evergreen, highly aromatic even when dry, and finely divided into strips. The leaves are bipinnately lobed, feathery, and dark green with silvery reflections.

Exuberant and undemanding, this plant, commonly found in cottage gardens, brings a nostalgic charm to unpretentious beds. The 'Petra' yarrow blends well in rockeries, atop walls, along borders, or on slopes, where it helps stabilize and protect against erosion. This runner plant can be used as ground cover over large areas, eliminating the need for mowing in low-traffic zones. It can tolerate competition from tree roots, making it a good ground cover for woodland edges as well. Since it is easy to grow and withstands drought well, it is perfect for dressing the base of shrub roses or bordering a sunny bed.

According to Pliny, the Roman naturalist of the first century AD, its name comes from Achilles, a hero of Greek mythology, who used it to heal wounds. Achilles is said to have discovered the healing power of this plant during the Trojan War, when he treated a wound following Venus' advice.

In fact, the plant has recognized medicinal properties: it is hemostatic, the leaves have healing properties, and the flowers have a stimulating, tonic, and strong concentration febrifuge effect.