Felon Herb (Mugwort, Artemisia vulgaris)

Felon Herb, Mugwort, Riverside Wormwood, Wild Wormwood

Common mugwort (Artemisia vulgaris) is an herbaceous plant often found in nitrogen-rich soils. The plant’s scent is reportedly a mild insect repellant. Common mugwort is used as an offering in Nepalese temples. Tradition holds that it has cleansing properties, so believers also use it to sweep their floors to give them both a spiritual and physical cleaning.

I. Appearance and Characteristics 

Artemisia vulgaris, the common mugwort, is a species of flowering plant in the daisy family Asteraceae. It is one of several species in the genus Artemisia commonly known as mugwort, although Artemisia vulgaris is the species most often called mugwort. It is also occasionally known as riverside wormwood, felon herb, chrysanthemum weed, wild wormwood, old Uncle Henry, sailor’s tobacco, naughty man, old man, or St. John’s plant (not to be confused with St. John’s wort). Mugworts have been used medicinally and as culinary herbs.

A. vulgaris is native to temperate Europe, Asia, North Africa, and Alaska, and is naturalized in North America, where some consider it an invasive weed. It is a very common plant growing on low-nitrogen soils, such as waste places, roadsides and other weedy and uncultivated areas.

A. vulgaris is a tall, herbaceous, perennial plant growing 1–2 m (3 ft 3 in – 6 ft 7 in) (rarely 2.5 m (8 ft 2 in)) tall, with an extensive rhizome system. Rather than depending on seed dispersal, it spreads through vegetative expansion and the anthropogenic dispersal of root rhizome fragments. The leaves are 5–20 cm (2–8 in) long, dark green, pinnate, and sessile, with dense, white, tomentose hairs on the underside. The erect stems are grooved and often have a red-purplish tinge.

The Ukrainian name for mugwort, чорнобиль (chernobyl) translates as “black stalk”, and the Ukrainian city of Chernobyl gets its name from the plant. The small yellow or brown rayless flower heads are 5 mm (3⁄16 in) long, radially symmetrical and arranged in racemose panicles. The outer flowers in each capitulum are female and the inner ones bisexual. It flowers from midsummer to early autumn.

Several species of Lepidoptera (butterflies and moths) such as Ostrinia scapulalis feed on the leaves and flowers of the plant.

II. How to Grow and Care

Although it prefers plenty of sun and well-draining soil, once it’s established, mugwort is hardy, drought-tolerant, and can cope with a variety of conditions.

It’s even thought that infertile soils and dry conditions can increase the longevity and aromatic intensity of the plant, and it won’t grow as tall.

Sunlight

Common mugwort can tolerate partial shade, but grows best under full sun. A sunny garden border will be a good place for it. If you are growing your common mugwort in containers, place them near a sunny windowsill if indoor, or where bathed in sunlight outdoors.

Temperature and Humidity

This species is known for surviving across a wide range of temperatures. If you live in a region that experiences high heat and humidity during the summer, however, the foliage can begin to droop and won’t look as healthy. The thick and tall stems can be prone to flopping too.

Watering

Seedlings and young plants of common mugwort need regular watering. But once it matures, the plant becomes drought-tolerant, and no additional watering is required then. However, if the plant is cultivated in areas that are rainy or humid, you should pay attention to the drainage of the soil, as it may die back when the soil is soggy.

Soil

Mugwort is tolerant of a variety of soil types, including those with high alkalinity or nitrogen content.

Although it prefers slightly moist and well-draining soils, it survives well in dry and infertile conditions. In fact, although the plants won’t grow as high, it can result in more aromatic and long-lived specimens.

Fertilizing

Common mugwort does not like rich soils, so it does not require any additional fertilizers. Over-fertilization may lead to leggy growth and look badly. Just use a little compost, manure or other organic fertilizers in spring or fall, then it will provide all the necessary nutrients for the plant.

Planting Instructions

Before planting, till the beds and remove any rocks, clumps, roots, and weeds that you find. Amend the soil with lots of compost and a little bit of balanced all-purpose fertilizer to provide food for your plants throughout the season. Follow the directions carefully for how much fertilizer to add to the soil, as too much fertilizer will burn the roots.

Space plants out about 12” to 18” and provide another 12” to 18” space around the outside of the plants for weeding. Take the transplants out of their pots and cut them down to around eight inches long. Put them in the ground so that they are sitting around the same depth in the soil as they were in their starter pots. Fill the soil back in around the plant and pat it down with your hands and then water it well to help it adjust to its new home and to help settle the soil.

Pruning

Pruning method is quite different for different species and cultivars. Generally, you can cut your Artemisia plants back to the base in fall or spring to encourage growth in the following year. While with evergreen or late-flowering species such as tree wormwood (Artemisia arborescens) and sweet wormwood (A. vallesiaca), pruning should be performed in early spring, when there is no danger of frost, but before the new growth starts. Remove wilt flowers as well as dead branches, and leave only new shoots.

If the plant is not pruned, it can get really tall (1.5 to 1.8 m). Trimming some terminal leaves and branches in summer can return the plants that grow wild into a more favorable shape. If the plants get very bushy and thick, the air between the leaves will become more humid – favorable for powdery and downy mildew to develop. Thinning out the plants a little bit to improve the airflow and prevent these diseases. More intensive thinning is necessary if the plants are grown in very humid climates.

Besides, it is very important to wear gloves while pruning common mugwort because its repelling chemicals can also irritate the skin.

Propagation

Common mugwort can be propagated by seeds (some annual Artemisia species are self-sown) or cuttings. Propagation by cuttings includes taking 8 to 10 cm cuttings in late summer and rooting them in a loose, sandy compost or perlite. It is best if the rooting powder is applied before putting the cutting into the medium. Spray water every couple of days to keep it moist.

After a week or two, the cuttings will root. When the roots start protruding from the medium, it is time for a transplant. Rooted cuttings can be put into a separate container or planted directly into the soil in the garden. The distance between the cuttings should be at least 38 cm.

Transplanting

The perfect time to transplant common mugwort is during the pleasant warmth of mid-spring to early summer. Choose a location with well-drained soil and ample sunlight for optimal growth. For effortless transplanting, water common mugwort thoroughly a day before the process.

Pests and Diseases

Insects tend to avoid artemisia because of its aromatic nature, so disease and pests are rare, but leaf rust, powdery mildew, and downy mildew can be an issue in humid conditions.

III. Uses and Benefits 

The gentle fragrance of common mugwort makes it popular in herb and cottage gardens. This graceful plant works well as a border plant or an accent for wildflowers. It produces decorative flowers during the summer and fall, which also draws in butterflies and bees. There are several cultivars, so you can find a variety that will serve your garden needs.

Traditionally, it has been used as one of the flavoring and bittering agents of gruit ales, a type of unhopped, fermented grain beverage. In Vietnam as well as in Germany, mugwort is used in cooking as an aromatic herb.

In China, the crunchy stalks of young shoots of A. vulgaris, known as luhao (Chinese: 芦蒿; pinyin: lúhāo), are a seasonal vegetable often used in stir fries.

In Nepal, the plant is also called titepati (tite meaning bitter, pati meaning leaf) and is used as an offering to the gods, for cleansing the environment (by sweeping floors or hanging a bundle outside the home), as incense, and also as a medicinal plant.

The dried leaves are often smoked or drunk as a tea to promote lucid dreaming. This supposed oneirogenic effect is reported to be due to the thujone contained in the plant.

IV. Harvesting and Storage

How to harvest

When mugwort is in bloom, use clean, sterilized shears to snip off the top third of the plant. Depending on how it is being used, mugwort can be harvested at various times throughout the year and in multiple ways. Some people harvest young shoots in the springtime before it blooms, while others cut and dry a portion of the upper side of the stalk in the late summer or fall. 

How to store

Mugwort can be stored for future use by drying the herb to preserve it. Gather up bundles of mugwort made of several stems held together. Use twine or a rubber band to tie the herbs together at the base of the bundle. Find a warm, dry place where you can hang the bundles upside down out of the sunlight, such as a basement, shed, or garage. It should be a place with plenty of air circulation where the drying herbs are not at risk of being exposed to insects or too much humidity. Take care not to make bundles for drying too big, or they will not dry out quickly enough and may struggle with rot or mold.

Mugwort’s tendency to proliferate makes it a very easy herb to grow and care for, and the more mugwort you grow, the more uses you’re bound to find for it. Why not add some mugwort to your herb garden this year?

Mugwort plants are cultivated for ornamental, culinary, and medicinal purposes. Growing mugwort is relatively easy. The hardest part about growing the plant is germinating the seeds and keeping the plant from growing into areas where it is not wanted, or suffocating the plants in its near vicinity.

Felon Herb (Mugwort, Artemisia vulgaris) Details

Common name Felon Herb, Mugwort, Riverside Wormwood, Wild Wormwood
Botanical name Artemisia vulgaris
Plant type Perennial
Hardiness zone 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Growth rate Fast
Harvest time Fall
Height 2 ft. 0 in. - 5 ft. 0 in.
Width 2 ft. 0 in. - 5 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Loam (Silt)
Flower color Gold/Yellow
Leaf color Green