This shrub is typically forming multiple trunks and a densely branched crown that is often more broad than tall. Individual trunks are up to 4" across, gray to grayish brown, and relatively smooth. This shrub is monoecious, producing male (staminate) and female (pistillate) flowers on the same plant. Prefers partial sun or light shade, wet to moist conditions, and an acidic soil that is rocky, gravelly, or sandy. The root system fixes nitrogen in the soil and it reduces erosion along streambanks. Great plant for a Rain Garden center piece.
It is a great host plant for beetles, aphids, moth caterpillars, and other insects. Seeds, buds, or catkins of alders are eaten by such birds as the American Woodcock, Swamp Sparrow, Eastern Goldfinch, Common Redpoll, White-Winged Crossbill, and Pine Siskin. The extinct Passenger Pigeon also fed on the catkins. Because Brookside Alder is often a densely branched shrub, it provides cover and nesting habitat for the American Woodcock, Rusty Grackle, and other birds.
Soil Type: Rocky, Gravely, or Sandy
Soil Conditions: Wet Mesic-Dry Mesic
Male - Brownish yellow
Female - not showy
Early -Mid Spring
Height: 5 - 15' Wet - Wet Mesic
Light: partial sun or light shade
Credits: Info courtesy of Illinoiswildflowers.info; Photo courtesy of John Ruter, University of Georgia, Bugwood.org