By Mary Gold, Sonoma County Master Gardener
Achillea is a dependable Mediterranean perennial with gray-to-green, aromatic leaves, which are usually finely divided, or pinnated, making them appear feathery or fern-like. The Achillea flower is actually a flat cluster of daisy-like flower heads, 1/8 to 1/3², which are clustered in corymbs of between 3 to 5 inches across. The more commonly found Achillea is either white or yellow, but new cultivars and hybrids offer a very wide range of colors from pink to red to lavender. Some species originating from more mountainous regions are low growing mounds or mats. Some, originating from grasslands, are the taller variety. All of them should be grown in an open site with full sun and well-drained soil. They will tolerate many different soils and conditions, but do require moderate to occasional water until established.
Care for Achillea is simple and straightforward. Remove spent flowers and trim back occasionally; divide when they get crowded in order to maintain their vigor. Problems with this ornamental are few, but aphids and rust have been identified and several diseases caused by fungi can occur. However, if planted in the right spot and given the simple care they need, few problems should arise. Rarely, contact with foliage may aggravate skin allergies.
An added benefit to these elegant flowers is that they are attractive to butterflies because of their flattened corymbs. If you are interested in attracting bees and butterflies (and who isn’t in Sonoma County?) then Achillea should be part of your garden’s palette. Imagine the bright golden yarrow with its grayish/green, feathery leaves amidst purple lavender and red salvia.
Achillea is a lovely addition to cut bouquets and the taller variety can be dried for a beautiful autumn or winter spray of yellow, which pairs well with orange Japanese lanterns (Physalis alkekengi) and dark brown cattails (Typha latifolia).
You should be able to find any type of Achillea to fit your needs. With 85 different species the variety is nearly endless. If you’re looking for a tall, white cultivar, try
A. ageratum ‘W.B. Childs’ or A. millefolium. (Be warned, however, A. millefolium, or common yarrow, can be invasive.) Yellow Achillea, which is my favorite and most commonly available in Sonoma County, are A. clypeolata, or A. filipendulina, either ‘Coronation Gold’ or ‘Gold Plate,’ among others. There’s always A. ‘Forncett Candy’, which is a light pink, or A. millefolium ‘Cerise Queen’ or ‘Island Pink’, both darker pink. Red is found in A. ‘Fanal’ which fades with age. A. ‘Terra Cotta’ or A. ‘Paprika’ work with earth-toned color schemes. Or, if you’re looking for something really interesting, look for A. ‘Summer Pastels’ which includes a combination of lavender, purple, white, apricot, cream, rose and pink.
Whichever species of Achillea speaks to you and your garden, remember that besides its reliability and sturdiness, Achillea is an important addition to any Sonoma County garden because of its drought tolerance and eye-catching appeal.