Drawn to spring in Sonoma County, I immerse myself in fields of lush green grasses and golden-yellow mustard. Entering Santa Rosa, Adobe and Petaluma Hill Roads are breathtaking in March, glowing in all directions. By summer, the fields will be shades of brown, a natural transition for California landscapes.
For those of you who desire green expanses year-round, consider the native yarrow, Achillea millefolium. In many urban and suburban areas, homeowners are now being asked to withhold water from their grass lawns. Native yarrow is the perfect turf for sunny and semi-shady areas in our arid climate.
But what about the children and dogs running? The badminton area? Croquet? A wedding? Yes, all these wonderful lawn activities can take place just as easily on a yarrow lawn. Yarrow is much tougher than grass, enduring high traffic, even a football game, once it establishes. And it is fire-safe.
There are several species and cultivars of yarrow. The California native recommended for a lawn is Achillea millefolium, or thousand-leafed yarrow. The rich green foliage is very fine with many leaves and a ferny appearance. Without mowing, white flowers bloom in summer.
For ideal growth, soil should be prepared as you would for a lawn, incorporating two to three inches of compost, and a supply of soft rock or colloidal phosphate (20 pounds per hundred square feet), plus five pounds of oyster shell for that same area.
If you are replacing an existing lawn, soil preparation is more complex. Since these grasses are perennial, not annual, they must be removed before the yarrow can grow without competition. Break up the sod with a tractor or rototiller, then remove as much of the old lawn as possible. It can be composted in piles, and even used to cover areas of poor soil where you are not gardening.
Fall sowing of seed is usually ideal, preferably done in September through October in microclimates where Indian summer slows the cooling of the soil. But spring sowing will work too. A half-pound of the fine seed is sufficient to cover 1000 square feet. If you are gardening in clay soils, do not mix sand with the seed. Seeded on top of compost, there is no need to cover the seed.
Spring-seeded yarrow should be irrigated frequently (unless it’s raining often) until germination, then once a week to encourage rapid growth for the first three months. In the warmer growing season, plants spread quickly by stolons. Fall-seeded, the Achillea millefolium seed will germinate quickly with early rains in the warm soil. In the winter months growth will slow, but the young plant will survive even weeks of dry weather.
If you mow the yarrow lawn area a couple of times in spring, there will be very few flowers, and those that do appear will probably be on soft, short stems to six inches. Taller stalks may, after mowing, leave stiff stubbles that are hard on bare feet. Allowed to bloom with little or no mowing, Achillea millefolium may have flowering stalks to two to three feet. Bloom is heaviest in early summer, and may continue lightly through fall.
Another approach is to seed the white yarrow in the area to be mowed, planting bulbs and water-efficient perennials, including any yarrow, on the perimeter and leaving them unmowed.
In one local foothill garden, an 8-foot wide yarrow path wanders through a small orchard, a permanent insectary. Unmowed, beneficial insects and pollinators have a sanctuary. The orchard may produce more fruit and have fewer problems.
Remember that once the yarrow lawn is established, withholding irrigation will maintain a low height, reducing mowing or weedeating to once or twice a season. And fertilizing your yarrow lawn? NEVER!
Carolyn has gardened organically in Nevada County since 1977. She is the author of the award-winning “The Seasoned Gardener, 5 decades of sustainable and practical garden wisdom”, and two volumes of “Deer in My Garden” (deer-resistant plants), available locally. For more information and details of upcoming classes, visit www.carolynsingergardens.com.