Sweetgale is faithful to its lovely name, exuding a spicy-sweet aroma from its glossy foliage rather than its flowers. Also known as sweet bayberry and sweet willow, it’s a low, spreading shrub with ascending branches and lance-shaped, deciduous leaves that give the plant the appearance of a shrubby willow. The bluish leaves are covered in waxy, resinous glands that emit a spicy odor when crushed (another common name is wax myrtle). The genus name comes from the Greek word myrike, meaning “fragrance.” Inconspicuous flowers are borne in catkins, followed by clustered cones of winged nutlets that persist into winter. The shrub is 2 to 6 feet tall with multiple stems that spread slowly by both branch layering and rooted suckers, often creating large islands of plants. It grows in a wide range of moist to wet soils and full to part sun, although it’s usually found in dappled light in the wild.
 
Sweetgale is classified as an obligate wetland plant, which means it almost always occurs in wetlands. It’s often found in the moist, peaty soils of bogs (another common name is bog myrtle), fens, coastal and inland swamps, and along the borders of lakes, ponds, and streams. Sweetgale’s roots contain nitrogen-fixing actinobacteria that enable the plant to grow in more challenging conditions. This symbiotic relationship with soil micro-organisms improves the soils not only for sweetgale but also for other vegetation growing nearby. This trait is typical of species in the Bayberry (Myricaceae) family, which also includes sweetfern and bayberry. Another beneficial characteristic of plants in this genus is resistance to honey fungus.
 
Myrica has a wide distribution that includes Africa, Asia, Europe, and North and South America. While it is not clear if Ohio is in its native range, it is only found in a few spots in Ohio. People worldwide have used these plants medicinally, and scientists are continuing to explore the secrets of their chemical compounds. The Celts used sweetgale to treat their wounds, and the Vikings took infusions of it before going into battle (BBC News, 1/19/2001). In modern times, researchers are hoping to find pharmaceutical uses for the plant’s chemical compounds. Currently, scientists are looking to sweetgale to increase crop survival during drought. Sweetgale excretes a chemical, myrigalone A, that is a potent inhibitor of ethylene biosynthesis (SCI, 2024). It's well-known that ethylene is key to fruit ripening, but the chemical also causes other effects in plants, such as encouraging root and shoot growth. Inhibiting ethylene production could increase crop survival during drought, block the germination of weeds, or slow the aging process of cut flowers.
 
Native habitats include bogs, fens, swamps, and edges of lakes, ponds, and streams. Sweetgale is great for stabilizing banks and shorelines. It can serve as a barrier or hedge in moist areas of the landscape. It can be propagated by layering or division.
 
Plant Characteristics:
Grows 2-6’ tall and 2-8’ wide.
 
Prefers part sun or dappled light but also grows in full sun.
 
Grows in a wide range of moist to wet soils, including sandy, loamy, clay, and acidic.
 
Cylindrical, 1/4 - 1/3” catkins appear late April to early May, before the leaves emerge. Male catkins form from lateral buds at the tips of one-year-old twigs and are slightly larger than female flowers. They are yellow with triangular, reddish scales, while female flowers consist of up to 25 tiny flowers with two red stigmas and oval bracts. Fruits, or drupes, are small, cylindrical clusters made up of winged nutlets, each about 1/2” long. Spongy bractlets act as flotation devices in water, which may aid in their dispersal to other wet habitats. The fruits ripen in July.
 
Alternate, simple leaves are spirally arranged, 3/4 - 2” long, and oblanceolate (tapered base and broader tip). Margins are minutely toothed, except for the tip, which has several pairs of shallow, rounded teeth. Both sides of leaf are covered with tiny, golden resin dots.
 
Reddish-brown bark has pale-brown lenticels. Slender, hairless twigs have resin dots. Branches are fragrant when bruised.
 
Reproductive System:  Male and female flowers are borne on separate plants (dioecious), so at least two plants are required for reproduction. This plant is occasionally monoecious and has the ability to change sex from year to year.
 
Wildlife Value:
Host plant for larvae of wide variety of moths. The fruits are a summer food source for a few species of birds, such as American tree sparrows. Sweetgale is a favorite food of beavers, and it also provides habitat for water birds and salmon.  
 
Medicinal, Edible, and Other Uses:
In Europe, the foliage is often used as an insect repellant or a parasiticide. Native Americans used a decoction of pounded branches as a diuretic. 
 
The fruit and leaves were once commonly used to both flavor and increase foaming in beer.  A tea made from the leaves is used to aid in dream recall and lucidity. Leaves and nutlets were used as a tea or a seasoning, although the essential oil is toxic in large doses.
 
An essential oil derived from the fruits is used in perfumes and, particularly in Scotland, to produce soaps to treat sensitive skin and acne.  
 
The Potawatomi used sweetgale to line blueberry pails to keep berries from spoiling. The Ojibwa made brown and yellow dyes from the branch tips or seeds.  
 
Queen Victoria’s daughter began a tradition of using sweetgale in royal wedding bouquets. It was most recentlyused  in the Duchess of Cambridge’s wedding to Prince William.
 
Caution: Sweetgale is an abortifacient and should not be consumed by women who are pregnant. The leaves are normally used as a tea, but they do contain a poisonous aromatic oil that may be toxic in large doses.
 
Resources:
Adirondacks Forever Wild: https://wildadirondacks.org/adirondack-shrubs-sweetgale-myrica-gale.html
 
BBC News: http://news.bbc.co.uk/2/hi/uk_news/wales/1126389.stm#:~:text=But%20he%20warned%20people%20against,into%20battle%2C%22%20he%20added
 
Plants for a Future: https://pfaf.org/user/plant.aspx?LatinName=Myrica+gale
 
Lady Bird Johnson Wildflower Center: https://nativeplantspnw.com/sweet-gale-myrica-gale/#:~:text=Distribution:%20Sweet%20Gale%20has%20a,almost%20always%20occurs%20in%20wetlands
 
SCI: https://www.soci.org/chemistry-and-industry/cni-data/2024/4/bog-myrtle-key-to-sustainable-ethylene-inhibition
 
Wikipedia: https://en.wikipedia.org/wiki/Myrica_gale