Sunday, August 31, 2008

Achillea millefolium
- White Yarrow

Part of the sunflower family, Achillea millefolium grows in full sun, but if used for a lawn substitute, usually is more satisfactory through the summer with a bit of shade, unless on the coast. As it is soft to the touch and spreads through rhizomes, we are experimenting with using it as part of a grassless “coastal lawn,” with other low-growing native herbaceous species, like coast strawberry, Pt. Reyes checkerbloom, and coast lotus.

For light traffic, not a soccer field. Cut every few months, don’t allow to go to seed. Leaves are aromatic, and foliage color ranges from dark green to silver gray. If let bloom in spring and early summer, its flowers will attract bees and butterflies. It is also found in Europe, and in California, local forms should be treasured.

Thursday, August 21, 2008

Tarweeds and the Fifth Season

Deep in the dense fogs of August, I see in the garden outside my study window a multitude of sunny yellow disks floating disembodied in the pervasive gray. Their scanty stems and petioles are scarcely visible, so that the blossoms themselves, with no visible means of support, seem suspended in midair. To say they are a cheering sight doesn't begin to express the impact of the native wildflower called elegant, or common, tarweed (Madia elegans), blooming in the days of fog.

California's unique "fifth season," the time when the true aridity of our region most expresses itself and no immediate hope of rain exists, is supposed to be quiet, restrained, and without much bloom, as befits a Mediterranean climate. Yet tarweed's drought-evading strategies allow it to blossom when the soil dries and cracks, days are long, and rain only a distant memory. The clay soils preferred by tarweed may retain sufficient moisture at depth to retard desiccation till seeds have set. An unusual mucilaginous substance in the leaf tissue also aids in water retention.

Elegant tarweed's lemony-yellow petals, yellow with just a hint of green, are fully open only at the beginning or the end of the day, or when we are enshrouded in fog. I say to garden visitors on a sunny day, "Oh, if only you had been here before the sun came out." In years when it has reseeded around my house, I can wander in a tarweed forest, inhaling its complex soapy fragrances, with their intriguing undertone of kerosene. It's a deep-summer-in-California smell, fresh and bracing. Hayfield tarweed (Hemizonia congesta ssp. congesta), found in fields between Bolinas and Olema, has a sharp, compelling odor and turns our midsummer coastal fields to gold.

I share my love of tarweed with a plenitude of insects. Once I collected seed from the hayfield tarweed mentioned above. In doing so, I disrupted bug paradise, a heaven of insect life going on in those seed heads. The collecting basket into which I beat the seeds was soon teeming with a diverse mass of insects madly trying to escape, now that they had been dislodged from their snug seed homes.

In August-to-October the small black seeds of elegant madia, beloved by finches, rest in the dried flower heads, the stalks forming a delicate tracery of gray. I find the fine blur of their crisp stems, holding on through the fall, to be quite gardenworthy, especially when planted in a relatively large area, at least one hundred square feet. Studies have shown that pollinators prefer such a patch to smaller, scattered populations one of many examples where good garden design creates good habitat.

A homeowner in Los Gatos, looking for a groundcover for the slopes around her new house, went to a nearby hillside to collect seed of Hemizonia congesta ssp. luzulifolia, a tarweed with pure white petals. It thrived and was attractive at all seasons, becoming the keynote plant of her garden—a good example of both a creative use of tarweed and the rewards of turning to local species for garden solutions. This gardener earns an honorary membership in the Tarweed Appreciation Society.

For native Californians, the beauty of wildflowers was literally mouthwatering. Linked with hopes for a bountiful seed harvest from which to make pinole (roasted, ground seed food), tarweed, with its rich and oily seeds, was an important component of the indigenous diet. In Grace Carpenter Hudson's painting The Tarweed Gatherer, held in the collection of the Grace Hudson Museum in Ukiah, California, a member of the Pomo tribe is depicted carrying a seed beater and gathering basket with which to harvest tarweed seed.

Indigenous land management practices fostered flourishing wildflower fields. One writer from the early 1900s referred to tarweed as "wild wheat," saying that the Indian's autumn begins when "the lemo- lo sap-o-lil (wild wheat or tarweed) had all been gathered and winnowed and the whole countryside could now be baptized with fire." Containers of tarweed seeds have been found in archaeological digs. Some of us are eating them again. If we partly owe their presence now to the management practices of West Marin's indigenous peoples, thank you for that. Thank you for tarweeds.

The Tarweed Gatherer by Grace Carpenter Hudson (1865–1937), a painter well known for her more than 600 portraits, mostly of Pomo people. Her anthropologist husband John was an outstanding scholar-collector of basketry and other ethnographic artifacts. This reproduction is courtesy the Grace Hudson Museum, Ukiah, California (;
special thanks to curator Marvin Schenck.