Projected change in summer temperatures under different warming scenarios. Summers in Illinois and Michigan might feel like current summers in Texas or Oklahoma by the end of the century.
 Source: United States Global Change Research Program 2009

Mulch, milkweed and rain gardens help adapt a yard for climate change.

On 2014’s wintry first day of March, Citizens’ Greener Evanston and Evanston TreeKeepers spoke to an overflow crowd at the Levy Center about climate-change-related improvements such as these, which City residents can make in their own back yards or on their parkways.

Louise Clemency, Chicago Field Supervisor for the U.S. Fish & Wildlife Service, explained the importance of maintaining a diversity of trees. Some trees that have not been common in this region will become good choices to plant as the climate changes. Trees that now thrive in Alabama, she said, may be thriving in Chicago by the end of this century.  

Birds and Their Meals

Birds depend on insects in trees and shrubs to sustain them on their migratory journeys, said Ms. Clemency.  Birds stoke up not only in forest preserves and parks, but also in back yards.  She said research has found that two-thirds of the bird species found in the local forest preserves are also found in back yards.

Certain trees matter more to birds than do others, and climate change affects that interaction. For instance, Ms. Clemency said, the flowers of the oak tree attract a range of insects that warblers eat. Because climate change is affecting the timing of birds’ migration and that of the arrival of spring at their migration destinations, birds may arrive too early or too late for the peak food supply. This is threatening their survival.

The Chicago region Audubon website states, “For homeowners, making your yard welcoming for migratory birds can be as simple as incorporating multiple layers and a meal at the right time.”

Milkweed and Butterflies

Ms. Clemency noted that monarch butterflies also benefit from vegetation diversity. Since milkweed is the sole food source for butterfly larvae, or caterpillars, they benefit from a variety of milkweed plants. Climate changes and certain herbicides used on corn crops can kill milkweed.

Rain Gardens

Bill Eyring, a retired engineer with the Center for Neighborhood Technology, spoke about the importance of rain gardens and other small-scale infrastructure solutions that help manage storm water. A rain garden can be thought of as a “parking place” for storm water, allowing it to penetrate the soil rather than run off in a large volume. Pollutants are removed as storm water infiltrates the soil, thus protecting local waterways.

Smaller green infrastructure improvements include porous paving, vegetated swales, native vegetation and detention basins. It is important to use native plants because they do not require pesticides, and their deep root systems enhance the infiltration of water into the ground. These improvements also prevent soil erosion and provide additional wildlife habitat.

Paul D’Agostino, assistant director of Public Works, Parks/Forestry for the City of Evanston, said the City is encouraging rain gardens and prairie gardens. For example, he said, the City worked with citizens on the development of the Howell Park community rain garden in northwest Evanston.

Winter Pruning and Mulching

Evan Shorr and Scott Lieber, arborists with Davey Tree Experts, explained the importance of pruning older trees and noted that winter is an ideal time for pruning. When the ground is frozen, it is sometimes easier for the arborist to reach the trees. In an urban environment such as Evanston’s, Mr. Shorr said, dead branches can be a safety concern and can cause interference with power lines.

Mr. Shorr emphasized the importance of proper mulching, so that air can get to the base of a tree, rather than “volcano mulching” – which is just what the name implies. Not all trees need mulching, he said, and mulch that is too deep can cause rot. He encouraged residents to use their mowers to mulch leaves right into the lawn.  

The arborists reminded everyone to always call JULIE at 1-800-892-0123, or 811, before digging, so that underground utilities can be located.

Buffalo Grass for a Parkway

Mark Wise of Greenwise Landscaping listed the negatives often associated with landscape companies, such as noisy equipment, volcano mulching, use of
toxic chemicals that kill pollinators and affect the watershed, use of non-native plants and the creation of stagnant and sterile landscapes. He urged workshop attendees to reduce the amount of non-functional lawn areas, keep water on-site as much as possible and use a good landscape designer.

Bernice Valantinas, a member of the Garden Club of Evanston, discussed her recent experience with planting buffalo grass, which grows to 6 inches and is drought-tolerant. On the parkway in front of her house, she replaced all existing soil with new soil and watered the new plantings frequently while they became established. Ms. Valantinas worked with Logic Lawn Care, a company that uses electric equipment and works very closely with the homeowner to accomplish their objectives.

At the end of the event, participants expressed enthusiasm about the possibilities for responding to the need to adapt back yards and gardening habits to the realities of climate change.

Ellen Galland has had an architectural practice in Evanston since 1983. For more than 20 years, she has written articles for the RoundTable, including the column “Ask An Architect" and "The Green Column"...