How To Grow And Care For Artemisias
Gardeners in the Southwest are constantly on the lookout for plants to provide some green that rustles in the breeze but can live in harmony with agave and barrel cactus. I’d like to suggest artemisias, a family of fragrant herbs that come from hot, dry regions of the Middle East.
Caring For Artemisias
Artemisias are generally trouble-free plants. Their strong scent discourages insects, probably the basis for their use indoors as insect repellant. They hold their own in the searing heat of summer and are hardly disturbed by freezing temperatures and snow. When problems do arise, it is because of too much water in the soil or humidity in the air, not something that is common in the Southwest.
Artemisias have minimal water requirements. They also tolerate poor soils, making them a good candidate for the problem spots every gardener seems to have. Plant them where their pale gray to green, feathery foliage will make a nice contrast to most neighboring plants.
Propagation of artemisias is so easy it’s almost impossible to avoid. When left on their own, they will gradually spread in garden beds. The branches will flop over and produce roots where they touch the soil. In the fall pull back or transplant any new side shoots.
Artemisias often are used as shrubs in garden plans. But unlike most other shrubs, these plants tend to get rangy above ground and aggressive below ground. Plan on clipping them more frequently than your other shrubs.
Artemisias that Grow Best In The Southwest
Citrus Scented Southernwood
Southernwood (Artemisia abrotanum) is a hardy perennial. Its feathery leaves have a fragrance somewhere between lemon and tangerine. This citrus-smelling herb grows two to three feet tall in full sun to partial shade. The leaves are finely divided and thread-like. In late summer it sends up thin spires with tiny yellow flowers.
As the old leaves drop off the lower portions of southernwood branches, the bark becomes woody and the sprawling herb takes on a somewhat disorderly appearance. Periodic harvesting or trimming will keep the plant bushy and attractive.
Before the discovery of germs and their role in disease, bunches of southernwood were combined with rue and carried as nosegays to prevent “jail fever” and other contagious diseases. It also had a reputation as an astringent and was used to fight acne. Today southernwood is generally not used in alternative medicine.
Wild Wormwood
Wormwood is the wild-child of this family. Besides its association with bitterness in the Old Testament, it is also one of the key ingredients to absinthe, a controversial, mind-bending liqueur popular with the scandalous artistic communities of the nineteenth century. Modern research has debunked that association but the reputation remains.
Wormwood has been used in the past to provide a bitter flavor to some liqueurs.
Wormwood (A. absinthium) grows two to four feet high, has finely divided silver leaves with a distinct aroma, and a bitter flavor, and tiny yellow flowers. It tolerates poor or gravely soil. Its low-growing shape and gray color make it a good companion to plants with a tall profile. Wormwood tends to be short lived, so plan on propagating it by division or layering every other year.
The most well-known wormwood artemisia is ‘Powis Castle’ (possibly A. arborescens x absynthium). This hybrid of uncertain origins is a woody sub-shrub that will grow in a wide range of poor soils and tolerates benign neglect. If you want it to serve as a groundcover, look for ‘Lambrook Silver’ wormwood, which grows only about eighteen inches tall and has very fine foliage. All that is required is annual pruning to keep these herbs in reasonable shape.
Common Mugwort For Brewing
Common mugwort is another pretty plant with an unappealing name. “Wort” is an old English word for any herbaceous plant. Mug-wort (A. vulgaris) is a plant used to make a liquor one drinks from a mug. It was one of the herbs that provided bitterness to beer and ale before the advent of hops in the Middle Ages.
This aromatic bush has dark green leaves with dense downy undersides. It grows best in full sun. Mugwort can be invasive, so plant it where it can ramble without disturbing less aggressive plants. Keep it from looking weedy by regular pruning. It can even be mowed once it is established.
‘Silver King’ western mugwort (A. ludoviciana albula) is an herbaceous variety bred from artemisias native to the Western U. S. It’s popular for its relatively compact form and lacy silver leaves. ‘Silver King’ grows to around three feet high with slender spreading branches. Its strong roots make it useful on slopes and areas requiring erosion control. However, those same roots tend to spread easily into unwanted areas. Mow ‘Silver King’ artemisia in the fall to encourage compact growth in spring.
French Tarragon, a Culinary Artemisia
French tarragon (A. dracunculus) is a pungent low-growing herb with soft needle-like leaves. It is the only member of the artemisia family used commonly in today’s cooking. French tarragon can grow in hot, dry areas with as little as 12 inches of annual rain. The thin stems are covered with long, narrow leaves and reach one to three feet high. In mid-summer French tarragon forms tiny greenish-white blossoms, but the seeds they produce are sterile and will not germinate.
When shopping for French tarragon, keep in mind there are two herbs called tarragon, probably stemming from the same parent plant. French tarragon, which provides the best flavor in foods, is a sterile hybrid and can only be propagated by cuttings or division. Russian tarragon (sometimes call A. dracunculoides), the supposed parent of French tarragon, can be grown from seed but is coarser in flavor. If you find a packet of seeds labeled “tarragon,” it is the less desirable Russian variety so don’t waste your money.
A New Landscape Artemisia
‘Seafoam’ artemisia (A. versicolor) is a recent introduction from England. The thready leaves are light gray and tightly curled. It makes a nice contrast with other plants with deep green leaves. ‘Seafoam’ artemisia will happily grow in sandy to gritty soil. Because it grows only about eight inches tall and twenty-four inches wide, it will work as a ground cover. However, gardeners in regions with high humidity will find this artemisia “melts” and fails to thrive.
To add some hardy foliage in your Southwest garden, try growing an artemisia. Their gray-green foliage and stimulating aroma are an excellent addition to any garden design.