Sweet Annie (Artemisia annua)
Qing-hao, Sweet Wormwood, Sweet Sagewort, Chinese Wormwood, Annual Wormwood
About This Plant
Sweet Annie is one of the well-known Artemisias loved by hobby farmers and flower growers alike for its long, plume-like, sweetly scented foliage and its ornamental value in wreath making, leaf pressing and flower arrangements. It is a self-sowing annual that grows up to five feet tall and equally wide. It is hardy to zone 7 and like many Artemisias, is extremely vigorous and essentially disease and pest free.
Sweet Annie is native to China and can be seen growing in the wild, growing in waste places, and at the edges of human habitats. Its size means it can take up quite a bit of space in the garden and as such is useful for filling in gaps at the back of a border. Its mature stalks are thick and woody and require loppers to cut. Its foliage is soft and fern-like, full and lush, and silvery-green in color. It can look quite lovely swaying in the breeze and makes a beautiful addition to flower arrangements. Its leaves are three to five centimeters long and divided by deep cuts into two or three small leaflets. Each feathery branch is covered with tens of thousands of small, yellowish-green flowers from August and September. Its small flowers are arranged in loose panicles. It does not produce large, striking blooms, but its sweet, luscious fragrance more than makes up for that.
Its aroma can be described as slightly balsamic and it has been used in perfumery. Its fragrance can be especially strong on a warm summer day. Sweet Annie attracts bees, butterflies, and birds and its scent helps deter other unwelcome garden pests. Its stems are erect and brownish or violet-brown in color. The plant itself is hairless. Sweet Annie’s scientific name Artemisia annua refers to its annual nature. It takes about 100 days from sowing to harvest leaf and flowers and takes about 160 days to set seed. Harvesting the branches before the setting of seed will limit or eliminate seed dispersal and keep the plant from becoming a pest. It can be grown in a container. Sweet Annie is a determinate, short-day plant and is not suitable for growing in the tropics because its flowering will be induced when the plants are still very small.
Sweet Annie is used as a dietary spice, herbal tea, and medicinal plant in its native growing region in the milder climates of Asia. It has historically been used as a treatment for malaria. Extensive research is being conducted on its use in the treatment of cancer. Most recently, it has made the news for being used in Madagascar as a treatment for Corona Virus and is an ingredient in the region’s Covid-Organics drink.
The sap of Sweet Annie can cause dermatitis in some people, so use gloves and caution when working with the plant. The pollen can be extremely allergenic in some people. It should not be used during pregnancy due to a potential risk of embryotoxicity at high doses.
Sweet Annie can be sown indoors six weeks before the expected last frost and transplanted outdoors once all danger of frost has passed. It can also be easily grown by directly sowing the tiny seeds into the garden a week or two before the Spring’s last expected frost. Seeds should be sown on the surface of the soil and kept easily moist until germination. Germination should take about 7-21 days at 70 degrees Fahrenheit. The very tiny seedlings grow rapidly and transplant well.
Seedlings can be transplanted once they have their second set of true leaves. Harden the seedlings off and transplant outside after the danger of frost has passed. Plants should be spaced 12-24 inches apart.
Sweet Annie tolerates most soils as long as they are well-draining. It will tolerate partial shade but likes to have at least six hours of full sun per day. It requires little moisture and little care once established. Plants are longer lived, more hardy, and more aromatic when they are grown in poor, dry soil.
Sweet Annie can grow quite large, so choose a location carefully. Plants can be pruned as needed. This plant self-sows and under some conditions can become invasive though it is easy to remove starts and smells great as you do so. Removing flowering branches before seeding helps to control self-sowing. Sweet Annie can be grown in a container.
To harvest for medicinal purposes, cut the branches from the plant just as the flower buds start to show a touch of yellow. This is when the artemisinin content is the highest. Hang the stalks upside down in a dark, ventilated space. It takes about 2 weeks for the foliage to thoroughly dry. The flower buds and foliage dries to a medium green. If using in dried flower arrangements, the flowers and foliage eventually ages to a soft brown. Allowing some of the flowers to open before harvesting will invite the bees. Be sure to cut the spent flowers from the stalks before any seed is dropped if you do not wish for Sweet Annie to self-sow. Leaves can be harvested in the Summer before the plant comes into flower and can be dried for later use. Leaves should not be crushed before long-time storage.
To save seed of Sweet Annie, harvest the mature flowers, hang to dry, and shake the seeds into a large paper bag. Seeds ripen from September to October, about 160 days after germination.
- Floral arrangements, wreaths, and pressed flowers
- Attracts bees, butterflies, and birds to your garden
- Used in China as a medium for growing Aspergillus which is used in brewing wine
- Dietary spice
- Herbal tea and medicinal plant
Sweet Annie is used in small amounts as an aromatic culinary spice in its native growing regions. Essential oil from the leaves is used as a flavoring in spirits such as Vermouth.
Sweet Annie is a source of artemisinin. The plant’s antimalarial and anti-carcinogenic properties continue to be studied by scientists around the world. The World Health Organization recommends Artemisinin-based combination therapies, know for short as ACTs, against malaria, especially those strains resistant to chloroquine, which is one of the main drug treatments for the disease. Research has shown that artemisinin destroys malarial parasites, lowers fevers and checks bleeding. In vitro studies also indicate that artemisinin may be an effective treatment for protozoal infections including leishmaniasis, chaga’s disease, and African sleeping sickness.
Sweet Annie has long found a place in traditional Chinese herbal medicine. It is an aromatic and antimicrobial herb that has also been shown to have anti-hyperlipidemic, antiplasmodial, anti-convulsant, anti-inflammatory, anticholesterolemic, and anti-viral properties. It is also hepatoprotective, antifungal, antitumor, antioxidant, and antiasthmatic.
It is often used internally in the form of a tea or pressed juice. Externally, the leaves are poulticed onto nose bleeds, boils, and abscesses.
Sweet Annie is native to China and southeastern Europe. It occurs naturally as part of the steppe vegetation In the northern parts of China at 1,000 to 1,500 meters above sea level. It is now grown in the temperate regions of the Americas, Africa, Europe, and Australia.