Yarrow is a very easy to grow plant that is drought and heat-tolerant, deer-resistant, and not susceptible to pests. While it may not fit into a formal garden, it blends well in a cottage garden or naturalized areas. Two popular hybrids are the yellow Achillea 'Moonshine' and 'Coronation Gold', but the millefolium hybrids are available in a wider range of colors, including 'Appleblossom,' the pink variety that I have.
Yarrow spreads quickly, although I would definitely not classify it as a thug. I started with two plants that I moved from our old house and planted them next to one of the large landscape boulders that border our driveway.
You can see in this larger view that they have grown to encircle half the boulder. Each spring I dig up extra seedlings and plant them in other areas that could use a spot of color or pass them along to friends. This year I planted some "Homestead Purple" Verbena in front of the boulder, which contrasted nicely with the feathery green foliage and the pink blossoms.
Although Achillea is not a showy plant, it does have some lofty origins. According to Anthony Kahtz' Perennials for Midwestern Gardens, "The genus was named for Achilles...who reportedly used the species millefolium to help heal the wounds of his soldiers. And so a common name of the species used primarily in England is soldier's woundweed."
Some other basic facts from Kahtz:
Hardiness: Zones 3a to 9a
Spread: 18 in. to 2 ft.
Season of bloom: Early to late summer.
As the flowers age, their blooms fade, eventually turning brown. They are a popular plant to use in both fresh and dried arrangements. One of these years I'm going to attempt drying some flowerheads, but so far my method of dealing with them is to shear them off once they turn brown. Kahtz mentions that they are tough plants that "can be mowed over and bounce right back." I can attest to that, having a rather mower-happy Husband who likes to get as close as possible to everything so he doesn't have to trim. But I'm guilty, too--as I said, I just shear off the plants once they begin to die back, and before long, green foliage and new blossoms reappear.
Achillea is not my "signature plant" nor my favorite by any means, but it should deserve some kind of an award from me. On my first-ever Garden Bloggers' Bloom Day post last March, it was featured as it was the only green emerging in my garden. And it was featured again on my last "real" Bloom Day post in November--"real" in the sense that November was the last time anything was really growing in my garden. Even today, after a month of winter and while a "wintry mix" is falling, there is still some green foliage showing. Definitely one tough plant!