Invasive Plant Management
In November of 2007 the Des Moines Park and Recreation Department began measures to control garlic mustard, an aggressive biennial plant that is an increasing threat to the aesthetics and ecological integrity of the woodlands in the city’s Greenwood and Ashworth Parks, located from 45th to 49th Streets, between Grand Avenue and the Raccoon River. Initial eradication efforts will involve herbicide application when the temperature is above freezing this fall through early spring; native plants will be dormant, but the garlic mustard plants will remain green and photosynthesizing. Native plants, which emerge later in the spring, will not be affected by the herbicide because the glyphosate herbicide, known on the retail market by such brand names as Roundup, is not residual in the soil. As is typically the case with herbicide applications, people are asked to stay off treated areas for 24 hours following treatment; dated signs along major entries to the park areas indicate when those portions will be again be available for use.
Intensive follow-up efforts using multiple control techniques over the course of the next four to five years are necessary in order to deplete the seed bank of the garlic mustard in the soil. Measures will include spring prescribed burns, further herbicide applications and cutting of plants. Thereafter, continued monitoring and routine maintenance as well as eradication by property owners adjacent to the parks will be necessary to prevent another outbreak of garlic mustard.
A native of Europe, the rapidly spreading plant was introduced in the United States in the mid-1800s for medicinal and herbal purposes and has no native predatory insects or other natural controls to curb its rapid spread in this country. Growing tall and dense within a few years, it crowds out woodland understory plants such as wildflowers, ferns and tree seedlings as well as wildlife habitat. Garlic mustard prefers shaded and semi-shaded areas, and spreads most rapidly in highly-disturbed areas such as along trails, waterways and forest edges. According to Cathy Mabry McMullen, Ph.D, adjunct assistant professor in the Department of Natural Resource Ecology and Management, Iowa State University,
Prescribed Burn Program
In nature fire is essential to maintain the integrity of the native prairie and woodland plant species located in our parks. Fire is a natural occurrence that helps the plant and animal communities in a park and controlled burning offers a safer way to use fire in a helpful manner. The benefits of prescribed burns include:
Aid in reducing the undesirable plants from invading our prairie and woodlands
Help maintain a rich diversity of wildflowers and grasses
Encourage oak and other native trees to naturally regenerate in our woodlands
Decrease threat of a wildfire by decreasing the accumulation of combustibles
Benefit water quality by aiding in the establishment of deep-rooted natives
Improve the natural beauty and enjoyment of our parks
Experienced park staff conduct the prescribed burns. The Parks Burn Crew has been certified in accordance with a nationally-standardized testing program for professionals participating in wild-land burns. Park staff members have studied fire behavior and fire control techniques to ensure the safety of the burn crew, residents and private property.
See the list of prescribed burn plans to learn more about the various burn plans in place for the park and trail systems.
Ewing Park Burn Plan Greenwood Park Burn Plan Gray's Lake Park Burn Plan
MacRae Park Burn Plan Meredith Trail Burn Plan Pioneer Park Burn Plan Union Park Burn Plan