Description

Description:

Achillea millefolium is a vigorous herbaceous perennial. It is commonly used is restoration projects and in native plant landscapes. The varieties from europe are very popular landscape plants.

The european varieties to be low growing; almost prostrate. The California forms tend to be upright, usually around 4" to 6" in height. The sand dune forms are particularly robust and tall.

Branching:

Alternate.

Leaves:

Pinnately dissected leaves, often with a feathery appearance. Yarrow leaves are usually aromatic, with a fragrance similar to sagebrush.

Flowers:

Achillea tends to flower in late spring or early summer. Most are white. There is a pink flowering form from the Channel Islands.

Seed and Fruit:

The abundant, small seeds ripen in mid to late summer. They stay in the flower head until it is shaken or moved sufficiently to make them fall out.

Plant Relationships

In older flora (eg - Munz and Keck), Achillea millefolium was considered to be a eurasion exotic. The California species were considered to be A. borealis and A. lanulosa, each with subspecies . However, according to Jepson, Achillea millefolium is considered the sole native species, with no recognized subspecies or varieties, and does not distinguish it from A. millefolium from the other parts of the US or eurasia. However, other sources may list many varieties in California and the rest of North America. They include:

A. millefolium v. alpicola
A. millefolium v. arenicola
A. millefolium v. californica
A. millefolium v. gigantea
A. millefolium v. millefolium
A. millefolium v. occidentalis
A. millefolium v. pacifica
A. millefolium v. puberula

(Western states)
(California endemic)
(Calif., Ore., Wash., Ida.)
(California endemic)
(exotic)
(All 50 states and all of Canada)
(Cal., Ore., Wash., Ida., Alsk.)
(California endemic)

Growing Conditions

Natural Range and Habitat:

Achillea millefolium is a circumpolar species that is found in California, across Canada and down the Rockies and eastern seaboard, as well as Asia and europe.
Achillea millefolium is most commonly found in native grasslands, but is also found in sand dunes, sea bluffs and a variety of locations with low vegetation.

Sun and Exposure:

Achillea millefolium grows in full sun.

Soil and Moisture Requirements:

Achillea millefolium is found in a wide variety of soil and moisture conditions. It is usually found in well developed grassland soils where there is enough moisture to support perennials. It can be found in drier sites, although it will go dormant early in these locations.

Horticulture and Restoration

Wildlife Habitat:

The flowers are widely visited by pollinators. The fragrance of the foliage is likely to repel herbivores. We never notice any grazing on Achillea.

Restoration:

Achillea millefolium is often used in oak woodland and coastal projects, as well as small native grassland restorations.

Uses in Landscaping:

Achillea millefolium is commonly used in landscaping as a low growing bedding plant.

Horticultural Comments:

Achillea millefolium is one of the most resilient plants we have found for landscaping. As long as it is placed in full sun, it can survive and grow. It benefits from rich, deep soil and regular irrigation.
Like most perennials, it suffers where there is competition from tall weeds and grasses.

Jepson (2012) (APG System)

Order:

Asterales

Family:

Asteraceae

Genus:

Achillea

Jepson (1993) (Cronquist System)

Order:

Asterales

Family:

Asteraceae

Genus:

Achillea