This fast-growing, multi-stemmed wetland shrub in the birch family is attractive, versatile, and easy to grow. It grows as wide as it is tall, filling out with dark green, egg-shaped leaves patterned with deep veins. The grayish bark (other common names are gray alder and hoary alder; Alnus translates to “made of wood,” and incana means “quite gray”) is speckled with conspicuous lenticels that turn warty and decorative with age. It’s native to much of Canada, the Lake States, and the northeastern United States. It’s often found in sedge fens in northeastern Ohio and is mostly confined to the glaciated areas of the northern part of the state (USDA.gov). While it’s commonly found in wetlands and swamps (another name is swamp alder), speckled alder grows in a wide variety of moist to wet, well-drained soils, including nutrient poor, and tolerates occasional drought. It often grows alongside willows in the wild but is less able than willows to tolerate prolonged flooding. Because of its size (15-25’ tall), it’s appropriate for planting under power lines and may be trained into a tree by removing the lower branches and suckers. It grows well as an understory species, but it really takes off when the overstory is removed and it can form dense thickets. It spreads easily through root suckering and a process called “layering,” where low branches take root and begin to grow into a separate shrub. In fall and winter, the shrub is decked out with cone-shaped female catkins and dangling male catkins that serve as a food source for wildlife. Flower and fruit production begin at about five to ten years. Male and female flowers (catkins) appear separately but on the same tree. Flowering occurs in early spring before leaves emerge (the inflorescences form in late summer the season before flowering). Fruits mature in August and September with seeds dispersing the following spring. 
 
Speckled alder has a reputation for usefulness. Because its root nodules harbor nitrogen-fixing bacteria, the tree is used to enhance timber-producing trees in the same manner that leguminous crops increase production of agricultural crops. It’s an excellent plant to use in the rehabilitation of disturbed sites due to its nitrogen-fixing bacteria, rapid growth, and tolerance of soil types. Rapid growth and suckering also make speckled alder an ideal choice for coppicing and pollarding. The shrub may be affected by aphids, powdery mildew, and leaf curl. 
 
Native habitats include stream banks, lake shores, moist meadows, wetland forests, bogs, roadsides, and disturbed sites. Good choice for nutrient-deprived soils. Useful as a windbreak. Use along stream banks for erosion control. 
 
Plant Characteristics:
15-25’ tall and wide.
 
Prefers full or part sun.
 
Grows in a wide variety of moist, wet, well-drained soils, including sandy, gravelly, loamy, clay, mucky, and nutrient poor. Tolerates short periods of flooding and occasional drought. 
 
Female flowers are red, ovoid, about ¼” long, appearing March-May in one or more separate clusters near male catkins on the same branch. Slender spikes of male catkins form in late summer, persist through winter and opening up in spring. Female catkins become cone-like clusters with winged nutlets. 
 
Alternate leaves are elliptic to ovate and 2-5” long with 9-12 nearly straight, parallel veins on each side. The margins are doubly toothed and the lower surface is dull green and hairy.
 
Numerous stems rise from the base. Thin and smooth mature bark is grayish to reddish brown with conspicuous whitish lenticels.
 
Wildlife Value:
Host plant to a significant number of  Lepidoptera larvae species, including bluish-spring moth, pepper-and-salt geometer, hubner’s pero moth, and doubleday’s baileya. The dense foliage provides cover for deer, rabbits, and other small and large mammals. Muskrats, beavers, and rabbits browse the twigs and foliage. Songbirds, woodcocks, and grouses eat the seeds, buds, and catkins. Beavers use the wood to build dams.
 
Medicinal, Edible, and Other Uses:
Native Americans used speckled alder to treat anemia, sore eyes, internal bleeding, urinary problems, sprains, bruises or backaches, and itching. Chippewa mixed the root scrapings with powdered bumble bees to ease difficult labor. A tea was made from alder to cure diarrhea and toothaches.