- How to Grow Artemisia
- Varieties of Artemisia
- Powis Castle Artemisia
- Wormwood (Artemisia absinthium)
- Sweet Annie or Sweet Wormwood (Artemisia Annua)
- Southernwood (Artemisia abrotanum)
- Roman Woodworm (Artemisia pontica)
- Beach Wormwood (Artemisia stellerana)
- Mugwort (Artemisia vulgaris)
- White Mugwort (Artemisia lactiflora)
- Western Mugwort (Artemisia ludoviciana)
- Tarragon (Artemisia dracunculus)
- Silver Mound (Artemisia Schmidtiana)
There are many varieties of Artemisia, experts are not sure on the exact number but it ranges between 200 and 400 species. The name of the genus comes from the Greek goddess Artemis. All varieties of artemisia are part of the daisy family called Asteraceae. Plants from this genus are native to many parts of the world, from Europe to Asia and Africa.
The use of these plants ranges from beautiful ornaments to gourmet herbs or powerful medicinal plants. Most varieties of artemisia have a very pungent fragrance, except for white mugwort and sweet Annie that have a sweet scent. French tarragon, one of the best culinary varieties, smells like anise. Except for tarragon, artemisia plants should not be grown near food plants or herbs because they are toxic.
This genus has some amazing medicinal plants including wormwood, mugwort and sweet Annie which can be a treatment for Covid-19 according to medical trials. This is due to artemisinin, which is the component of the plant used to treat malaria.
Within this Artemisia family you will find all kinds of plants which can be annuals, biennials and perennials. Some species have creeping roots which can make them quite invasive and gardeners have to contain them.
Most varieties of artemisia have yellow or white flowers that come in clusters. What makes this genus special is their foliage, which comes in many shapes. Leave colors range from dark green to silver and grey, even white! As a rule of thumb, silver or grey leaves are hairy (hairs are super small) or felted, while green leaves are smooth. The beautiful foliage of all varieties of artemisia contrasts quite well with a plain green landscape, which is why they are prized ornamentals.
How to Grow Artemisia
The most important thing to know when growing all varieties of artemisia is that they need well drained soils. With the exception of Artemisia lactiflora, most need dry soil. If the soil is damp most varieties of artemisia will not survive, as they will decline and get fungal and root problems. Add perlite or rice hulls if you have poor draining soil or it has too much clay. Water these plants during the first year until they become established. After, they are quite drought tolerant.
Since these all varieties of artemisia tend to have a strong scent, they are natural pest repellents. Aphids, scale, mites or leaf beetles may attack some species. But most of the problems that artemisias tend to have are fungus related, such as rust and mildew, or root rot. These problems are due to damp conditions because of over watering, high humidity or poor air circulation.
Most varieties of artemisia grow better in full sun, however some types will tolerate partial shade. As a general rule they should get at least six hours of sun per day. The majority are hardy in USDA zones 4-9, although they could be affected by humid summers. If you live in an area like this make sure they are not planted in rich soil. Do not fertilize because this can cause them to flop or live shorter.
Prune plants frequently to keep them compact or use sticks or cages to give them support. Larger varieties of artemisia will benefit from a big pruning early spring or late fall. Make sure to leave some live buds. Shear up to half off during mid summer to prevent splitting or flopping. Many prefer deadheading flowers to prevent reseeding and improve the appearance.
Plant all varieties of artemisia in the spring after the danger of frost has passed. Some species can grow from seed, while others need to be propagated by cuttings or roots. Divide your plants in spring or fall; this is recommended every two to three years to increase the vigor and extend plant life. Do not mist the cuttings too much as this could cause them to rot.
Varieties of Artemisia
Powis Castle Artemisia
This type of artemisia is a cross between Artemisia arborescens and Artemisia absinthium. Powis Castle is an evergreen perennial shrub that grows up to 3 feet tall and between 3 to 6 feet wide. Its leaves have a beautiful silvery green color. This plant rarely flowers, but if it does it produces yellow, silver flower heads that are six inches long. It is used as an ornamental plant because of its dramatic foliage.
Powis Castle grows in USDA zones 6 to 8, but it does not tolerate the summer heat or winter cold. It prefers neutral to slightly alkaline soil that is well drained. Just like other varieties of artemisia, this plant is drought tolerant but will rot in wet soil. Plant it in an area that has full sun and prune it in the spring to maintain its shape. Powis Castle is a toxic plant, so make sure not to consume it. Buy Powis Castle seeds here.
Wormwood (Artemisia absinthium)
Some varieties of artemisia such as wormwood can be found natively in many places such as North Africa and Eurasia. This herb grows between 2 to 4 feet tall. Wormwood‘s claim to fame is the absinthe liqueur (vermouth also has this ingredient) which was banned from many countries because of its exaggerated hallucinogenic claims. Thujone, a chemical found in this plant, can be toxic in very high quantities.
Woodworm is a medicinal herb that is excellent at treating parasites, including malaria, and stomach conditions. This is one of the most bitter varieties of artemisia. Leaves are green-gray and silky, resembling those of a carrot. Slugs love eating the leaves of this plant.
Sweet Annie or Sweet Wormwood (Artemisia Annua)
The medicinal benefits of Sweet Annie are incredible, because of a compound it contains that is called artemisinin which cures malaria. Recent studies also show that this plant could treat Covid-19. This plant is mostly grown to obtain this compound which is taken from its leaves.
To grow sweet wormwood you can propagate it from cuttings in the spring or cultivate it from seeds. It is more common to grow this plant by seeds which are tiny and should be sowed after all the danger of frost has occurred. For simplicity, it is best to buy a plant from the nursery. Like other varieties of artemisia, this plant needs well drained soil, direct sun and is drought tolerant. Buy Sweet Annie seeds here.
Southernwood (Artemisia abrotanum)
Some varieties of artemisia like southernwood are native to the south of Europe. This sturdy shrub grows to 3 feet or more in height. It needs to be pruned in the spring to keep its shape. Several of these plants can be placed as a low hedge. Leaves are green-gray, with threadlike segments, which stay lively throughout the summer. Stems are yellow-green and stay upright.
Southernwood has a pungent aroma that is similar to sage, which is useful to repel moths. However, this plant is the food of spittlebugs, which are tiny insects, that are not harmful. If you don’t want them simply hose them off. Propagate this plant by layering. Pin down a lower branch and cover it with soil until the roots form and then cut it from the mother plant. Transplant it when it is ready.
Roman Woodworm (Artemisia pontica)
This herb is native to the Southeast of Europe. It is one of those varieties of artemisia that is included in the list of invasive species since it has a tendency to spread. Do not encourage it by applying fertilizer. It is best to plant it in a pot or in a contained area. Roman wormwood grows between 1 1/2 to 3 feet in height.
It has delicate, triangular green-grey leaves. Since the leaves are fine, they are a good filler for arrangements and miniature wreaths. Roman wormwood, just like wormwood, is used in vermouth and other alcoholic beverages.
Beach Wormwood (Artemisia stellerana)
As it name suggest, this artemisia is native to the sandy beaches of eastern North America and northeast Asia including China, Japan, Korea, Far East Russia and the Aleutian Islands in the United States. It is a low growing plant that can spread. Beach wormwood can tolerate salt and drought. However, it cannot tolerate heat or humidity in the summers.
It prefers partially sandy soils that are somewhat loamy and well drained. This unique variety of artemisia can grow in soil with almost any pH from acid, basic to neutral. It is hardy to USDA zone 2. This evergreen perennial plant grows between 1 to 2 feet in height. Leaves stay throughout the year, while flowers bloom between July to September. Silver Brocade is a type of beach wormwood that has felted, white colored leaves and white color stems. Unlike other varieties of artemisia, this is not an aromatic plant. Buy beach wormwood seeds here.
Mugwort (Artemisia vulgaris)
Mugwort is native to Asia, Northern Africa, Europe and Alaska. Now it is found wild in North America, where it is considered an invasive weed in some areas. Many plants of the artemisia family are called mugwort by mistake. While some may be confused, the true mugwort is Artemisia vulgaris. People also call it by different names including common and wild woodworm, St. Johns plant (not to be confused by St. John’s wort), sailor’s tobacco, etc.
It is possible to grow mugwort in USDA zones 3-9. This herbaceous perennial is mostly reproduced by rhizomes, so you will need to contain it. It also produces seeds. Mugwort can grow between 3 to 6 feet in height and may need stalking or pruning to prevent the plant from flopping. Like other varieties of artemisia, this plant prefers well drained soils that are dry and lime rich. It can tolerate slightly alkaline to slightly acidic soils.
Mugwort has medicinal benefits, but it should be avoided by pregnant women since this plant is an emmenagogue and can provoke miscarriages. People can drink it in tea, pills, or tincture. This herb was also used to flavor beer, but hops was ultimately preferred. Buy mugwort seeds here.
White Mugwort (Artemisia lactiflora)
Native to China, this plant is different than varieties of artemisia since it blooms late in summer and fall. Large flowers are creamy in color and can be used for dried arrangements or cut flowers. This plant can grow up to 6 feet in height. Leaves are dark green, which contrast quite well a a background plant for colorful flowers and grey leaved herbs. The downside of white mugwort is that it is susceptible to rust and mildew. And that deer like this herb. Buy white mugwort seeds here.
Western Mugwort (Artemisia ludoviciana)
This type of artemisia is native to the western part of North America. It grows up to 3 feet in height. Its erect stems produce silver leaves which are quite sought after by florists since they make gorgeous arrangements and wreaths.
Silver king is one of the types of western mugwort. This specie has narrow, pale leaves at the top, while the bottom leaves are broader and more jagged. Silver queen is often mistaken with silver king. The main difference is that silver queen’s leaves are grayer and broader. Valerie Finnis is another cultivar that is not as popular. This plant has white leaves on the bottom and green-gray on the top.
Tarragon (Artemisia dracunculus)
French tarragon is the best culinary herb of all the varieties of artemisia. Russian tarragon, also called wild tarragon, is not as flavorful as the French variety. It is used to flavor soups and other dishes. Harvest leaves in the summer and dry them for later use. Medicinal benefits of tarragon include digestion aid, so it is used to flavor oily foods. This herb is toxic to cats and dogs, so keep them away from it.
This herb is native to a wide area of the Northern Hemisphere. It can be grown in USDA zones 5 to 8. Plant it after all the danger of frost has passed. Most people buy this plant from a nursery, but it is also possible reproduce it by root division. Roots are quite shallow so be careful when weeding, not to damage the roots. Seeds are usually sterile. Tarragon prefers to live in an area with moderate sunlight and a little shade in the afternoon. It needs rich, loamy soil (add compost) and good drainage. Buy tarragon seeds here.
Silver Mound (Artemisia Schmidtiana)
Native to Japan, this plant has glistering white greenish foliage that makes it an attractive accent plant or a low edging plant. Its flowers are not a prominent feature since it barely flowers. This plant is quite gorgeous in the spring or early summer, but it does not tolerate heat, causing the center gape to open sloppily, ruining its bushy effect. Your plant may just die if it gets too hot. Make sure to prune it at the first sign of drooping, which will stimulate new growth during the fall. It is best to trim the new wood and trimmings can be used to start new plants.
Silver mound is a low, cushion perennial plant that reaches 1 feet in height. There is another variety called Nana that is just 4 inches tall. Many people think both plants are the same, but they are different cultivars and silver mound is more popular. As other varieties of artemisia, this plant is toxic and should not be consumed.