Yarrow is a fast growing plant that horticulturists have hybridized so you can grow it in your garden if you wish. Common yarrow and western yarrow are two of the more widespread wild kinds of yarrow. The plant, also called milfoil in some circles, had great medicinal benefit to the Native-Americans and early civilizations of Europe and Asia, who used it to treat everything from wounds to headaches. In a wildflower garden setting, it needs room to spread, since this is one of its characteristics.
Yarrow has hairy leaves, with those of western yarrow, common in the American West, being almost fern-like. Yarrow can grow to 3 feet high but is usually around a foot tall. The biggest of the leaves exist at the base of a yarrow plant, which has a stalk containing a cluster of small flowers. There may be as many as 50 of these flowers in each cluster, with a small inner head encompassed by the petals. The individual flower is less than a quarter of an inch across, with the clusters as wide as 3 inches. In the wild, yarrow is a creamy white color, but the cultivars have a much more gaudy selection of shades.
Horticulture has produces many varieties of yarrow, which in nature are a fast spreader, growing from seeds and from underground rhizomes. Science has made the flowers on hybridized versions of yarrow larger and the stems sturdier. "Cerise Queen" is a pink sort of yarrow, while "Paprika" has reddish-orange flowers. "Fire King," as you might suspect, is bright red and "Lilac Beauty" gets its name from its purple flower heads. Larger yarrows that cross-breeders created include some with flower clusters as wide as 5 inches. You can find these yarrows listed under their genus name, which is "Achillea," followed by the cultivar's name.
If you wish to see yarrow growing and flowering in the wild you should have little trouble finding it once you know what it looks like. Yarrow is a plant that grows along highways, near old buildings, in vacant lots, in open fields and along woodland borders. According to the "National Audubon Field Guide to Wildflowers," yarrow ranges throughout most of the North American continent. It is seldom growing as an individual plant, but is common for yarrow to exist in great numbers wherever you find it.
Choose to plant yarrow in the poorer soil sections of your gardens or property, but remember that it has a habit of spreading--even the hybridized yarrow. Refrain from using fertilizer, as yarrow will thrive and actually live longer without it. You must plant yarrow in a full sun location where the soil drains reasonably well. You should water it until it gains hold, at which point it will be very hardy and endure dry periods with ease. Hot temperatures tend to make the colors of the hybrids a bit duller and weaken the stems.
Consider yarrow as a ground cover plant, since it will spread out enough to form a continuous area of green if you space them correctly when planting them. By keeping yarrow about 2 feet from the next plant, you will have ground cover by the start of the next growing season. You have the option of picking the flowers, which the Floridata website states will keep their color if you can dry them rapidly. Keep an eye on how far your yarrow creeps out from where you intend it to grow. You can always stop their spread by digging up the "invaders" and putting them elsewhere or giving them to friends.