Mother Nature's Backyard - A Water-wise Garden: Plant of the Month (December) : California Mugwort

California Mugwort (Artemisia douglasiana): Mother Nature's Pollinator Garden

Few plants are blooming right now. But several perennials are starting to come back, thanks to the cooler weather – and a little judicious watering. One of these – the first species planted in our new Bie Havn Pollinator Garden - is the California mugwort, Artemisia douglasiana. Our Plant of the Month has an easy-to-pronounce scientific name: ar-teh-MEE-see-uh dug-LASS-ee-ANN-uh. It’s yet another example of California’s many species in the Sunflower (Asteraceae) family.

California mugwort is also commonly known as Douglas’ sagewort. The genus name, Artemisia, is the old Latin name for the wormwoods and mugworts. The name probably honors the Greek goddess Artemis. The species name douglasiana honors David Douglas (1798-1834), an early Scottish plant collector in the Columbia River region of the Pacific Northwest and in northern California. A number of native plants honor Douglas (the most common is the Douglas fir). Specimens he collected for the Horticultural Society of London were an important early introduction of our west coast native plants to a European audience.

Artemisia douglasiana is native to the western U.S., from Washington and Idaho south to California and Nevada. Growing in most of the lower elevations of California (below about 6000 ft; 1800 m.), it can be found in the moister areas of many plant communities including Chaparral, Coastal Sage Scrub, Northern and Southern Oak Woodland, Mixed-evergreen Forest and Yellow Pine Forest.

California Mugwort (Artemisia douglasiana):
Gardena Willows Wetland Preserve

Mugwort is also common around freshwater marshes and in moist meadows. It once grew extensively in the coastal wetlands of western Los Angeles County, and can still be found in the Santa Monica and San Gabriel Mountains and on Catalina Island. It was common along the Los Angeles and San Gabriel Rivers and their larger tributaries. You can see it in a natural setting in the Gardena Willows Wetland Preserve.

California Mugwort (Artemisia douglasiana):
plants die back in fall

California mugwort is a part-woody, perennial groundcover plant in the Sunflower family (Asteraceae). It dies back in the fall (the best time to prune it) and sends up new shoots and branches with the cool, wet weather of winter. It’s a spreader; it increases via underground stems (rhizomes), by rooted stems (where they touch the ground) and by seed. This is a natural groundcover and will fill an area given time. If you want to limit its growth, you’ll need to contain it.

California Mugwort (Artemisia douglasiana)

Artemisia douglasiana is known for its erect stems and fresh green foliage. The stems are 1-5 ft. (50-250 cm.) tall and somewhat woody at the base. The stems are upright or recumbent (lying down). Older, unpruned stems often lie on the ground and send up new, upright branches. Mature clumps of Mugwort can be as much as 10 ft (3.5 m.) or more across in favorable sites.

California Mugwort (Artemisia douglasiana): new stems

The foliage is pale green on emergence, becoming medium green above and a pale green beneath. The underside of the leaves are covered with dense hairs. The plants can turn their leaves, bottom-side to the sun, as a protection against hot, dry conditions. The leaves are simple and coarsely-toothed. They are slightly succulent, softly hairy and have a fresh, slightly pungent odor when crushed.

California Mugwort (Artemisia douglasiana): leaves

California Mugwort (Artemisia douglasiana): mature leaves

California mugwort is not one of our showy native sunflowers. It’s more like California sagebrush; small green-gold flowers, densely spaced on the tips of the stalks. The flowers do attract the insect pollinators: native bees, pollinator flies and butterflies. And the seeds are eaten by the seed-eating birds in fall (watch for Goldfinches and White-crowned Sparrows). The plants themselves provide cover for ground-dwelling and feeding creatures like lizards and birds. So Mugwort is a good plant for providing general habitat.

California Mugwort (Artemisia douglasiana): flower buds

California Mugwort (Artemisia douglasiana):
flowering plants

California mugwort is fairly easy to grow. In our hot S. California gardens it prefers some afternoon shade. It does well in dappled shade (or even darker) under trees. It’s not particular about soil texture; we’ve grown it in both very sandy and clay soils. It looks better with occasional summer water – a deep watering once or twice a month from May to September should suffice.

California Mugwort (Artemisia douglasiana):
prune back old stems in fall

A Mugwort clump really needs to be cut back in late fall. We cut ours back almost to the ground. No need to be persnickety when pruning – we sometimes just pull up the old, woody stalks and break them off. This is also a good time to pull up stems that have grown beyond their desired perimeter.

California Mugwort (Artemisia douglasiana): groundcover

Mugwort is a handy plant for shady spots under trees, where a green non-ivy groundcover is needed. It does well on slopes, and will help bind the soil. We often mix it with the Woodmints (Stachys species) and Hummingbird sage (Salvia spathacea) for a mixed groundcover. It’s a great plant for locally-themed gardens, giving just the right ‘wild’ element.

California Mugwort (Artemisia douglasiana): on slope
'Garden of Dreams' Discovery Garden, CSU Dominguez Hills

It’s also a candidate for the medicinal garden, with a long history of traditional use. In fact, Mugwort’s medicinal properties are currently being evaluated for use in Western medicine. A topical (skin) application of a decoction (tea) made from the leaves is affective against a number of micro-organisms. Rubbing the leaves on affected skin is said to be soothing for poison oak rash. And the leaves do provide a non-greasy ‘hand lotion’ for the hands; we often rub the leaves between our hands after a day of gardening. Works like a charm on dry hands!

California Mugwort (Artemisia douglasiana): medicinal leaves

As a medicine, Artemisia douglasiana should not be taken lightly. It is powerful medicine and should be used sparingly and under the care of a practitioner. It is sometimes used as a tea for stomach and gastrointestinal ailments. The plant chemicals have cytotoxic (cell-killing) properties, so this is not a medicine to use indiscriminately. For more on the medicinal properties of this plant see references 1-3, below.

Mugwort also has another interesting property: it induces vivid dreams. Some native traditions believe that sleeping on a pillow of Mugwort leaves will bring dreams of one’s future spouse. We not sure of that, but it does induce vivid, technicolor dreams (we tried it). It’s certainly not a sleep aid!

In summary, Artemisia douglasiana is a useful plant if you have the right place for it. It’s a great all-round habitat plant that looks good much of the year. It’s carefree (except for fall pruning) and can be contained. It’s not the showiest of our California natives, but it’s a reliable groundcover for shady spots.