advertisement

Illinois' colorful sumacs often mistaken for poisonous cousin

Who needs the beautiful maples of New England's fabled fall colorama? Have you seen the brilliant reds and oranges along our own expressways? Our native sumacs are giving a fiery show to rival any maple on the East Coast.

There are many misconceptions about sumac. At a holiday dinner last year, my sister-in-law displayed the lovely dried plume of a sumac. The family reacted like vampires confronting garlic. "It's sumac!" someone cried in horror. Everyone backed away.

Family lore held that one aunt had had an allergic reaction to sumac.

"Poison sumac is quite rare around here," says Kunso Kim, the Morton Arboretum's assistant director of collections. Thriving primarily in acidic bogs or wetlands, poison sumac sometimes can be found in areas such as Volo Bog in northern Illinois or Cowles Bog in the Indiana Dunes. The typical roadside sumac, however, is quite harmless. So much for family lore.

Instead, the glorious scarlet plume brought to our holiday dinner most likely derived from a staghorn sumac (Rhus typhina), one of many benign and beautiful native sumac shrubs. Although sumacs are generally grown for their brilliant fall color and ease of care, Kim says people sometimes collect the plumes (which are actually fruit clusters) for flower arrangements. Staghorn sumac colors range from a vibrant orange to a rich red.

Native to Illinois, smooth sumac (R. glabra) has glossy green leaves in the summer, and can grow up to 20 feet tall. The leaves stay shiny during the fall season and become a brilliant scarlet. They shimmer with reflected light of autumn's gentle sunshine.

Kim is especially fond of Prairie Flame shining sumac (Rhus copallina var. latifolia 'Morton'), a selection of shining sumac.

"I think it has the most brilliant color," he says.

With a more refined, compact habit, this sumac derives from R. copallina and has stunning red-orange, glossy leaves.

The genus Rhus has more than 200 species so it is not surprising that you can plant a collection that will provide continuous fall color. Chinese sumac (R. chinensis), for example, typically begins its show of color earlier than others. While it can grow up to 25 feet high, more typically it ranges from 12 to 15 feet. It also has shiny leaves that turn a brilliant orange, red or yellow, and "light up the whole area," according to Kim.

A popular landscape plant is 'Gro-Low' sumac. Used as a groundcover, 'Gro-Low' is so-named for its 2-foot height. Also true to its botanical name (R. aromatica), 'Gro-Low' leaves and branches have a distinctive, herb-like fragrance when crushed.

Some gardeners say sumac's suckering habit is a downside, but Kim says it's a benefit.

"It will form a nice thicket," he argues. "In fall, you'll see a beautiful undulating wave of color."

Sumac's propensity to form colonies can be tamed, Kim notes, by occasionally using a spade to dig out unwanted offshoots. By surrounding the sumac grove with deeply dug landscape edging, you can prevent the suckers from growing.

Or, just let them grow and enjoy the color show throughout the whole fall.

• Cathy Maloney is an avid gardener and a writer for the Morton Arboretum. Her column appears monthly.

Sumacs spread easily, giving growers big patches of shiny red leaves. Laura Stoecker | 2006
Article Comments
Guidelines: Keep it civil and on topic; no profanity, vulgarity, slurs or personal attacks. People who harass others or joke about tragedies will be blocked. If a comment violates these standards or our terms of service, click the "flag" link in the lower-right corner of the comment box. To find our more, read our FAQ.