Prairie Restoration and Conservation

Middleton has a very in-depth conservation effort, and a huge part of this is the closely monitored prairie restoration. We are actively stewarding the prairies to enhance biodiversity, promote native plant species, and create a thriving ecosystem for the benefit of our residents and wildlife.

The Planting Process

Effective prairie restoration requires careful planning and implementation. One of the essential steps in preparing for prairie planting is several years of cropping prior to the actual planting. This involves clearing and burning the whole area intended for prairie. By doing so, we create an opportunity for weed seeds in the soil to germinate and be eliminated, reducing competition for newly sprouting prairie plants. Any plant material left on the ground after the last harvest acts as mulch, helping to retain moisture and protect prairie seedlings from drying out.

At Pheasant Branch Conservancy, one of our prominent prairie sites, the actual planting process involves the hand broadcasting of seeds onto the ground.  Plantings are done both in the fall and spring, and the number of species planted varies per planting. Fall planting allows the seeds to overwinter naturally, benefiting from the cool, moist period required for germination and facilitating seed incorporation into the soil through frost heaving and snow melt.

The design of a prairie requires some forethought. The pattern of seed dispersal varies based on the moisture requirements and aggressiveness of the species involved. Some less aggressive plants that thrive across various moisture regimes are spread uniformly across the entire site. However, more specialized or aggressive species are dispersed in targeted patches within areas suitable for their growth. By recreating these natural conditions, we promote species' resistance to encroachment by more aggressive plants and enhance the likelihood of successful pollination and seed production.

Prairie Plant Growth

Prairie species invest significant energy in below-ground growth during their early years, developing deep root systems that allow them to survive in drought-prone grassland regions. As the prairie plants mature and establish their root systems, they outcompete the weaker annuals, resulting in the gradual fading of weeds. The initial stages of prairie plantings often display a dense growth of opportunistic annual or short-lived weeds, alongside slower-developing prairie plants, but after five to eight years, successfully planted areas exhibit a vibrant array of prairie plants. This is quite visible in particular at Bock Prairie and Forest, where a majority of our seed collection takes place because of the deeply established prairie species.

While prairie restoration aims to establish diverse native species, there are instances where prairie plantings do not survive the weedy stage. Factors such as variations in soil composition or disturbances in the area can affect the success of the restoration. In such cases, the area may revert to the growth of common weedy species. Prairie restoration is an ongoing process that requires constant efforts to ensure long-term success, so Middleton continuously monitors the prairies and uses mechanical extraction and herbicides to control unwanted species.

Prairie Maintenance

Invasive species, defined as non-native plants, pose a significant threat to prairie restoration. Some invasives, such as buckthorn, honeysuckle, garlic mustard, and reed canary grass, can harm native populations, displacing them entirely and forming dense stands where native plants struggle to survive. Invasive species became widespread in the 1800s due to increased transoceanic travel, with many initially introduced as ornamentals or for erosion control purposes.

To combat invasive species, the City of Middleton actively monitors their arrival and implements control measures. The Forestry and Conservancy department works in collaboration with volunteers, county naturalists, and caretakers from various natural areas. Herbicides are a primary tool used for controlling invasive species. For woody invasives like buckthorn and honeysuckle, cutting alone is not sufficient, as they tend to resprout from the cut stems. Instead, the preferred method involves cutting the stems near ground level and applying herbicide to the stumps, effectively killing the plants.

It's important to note that even after the treatment of invasive species, a seed bank may remain in the soil, necessitating ongoing monitoring and management efforts. Restoration work involves limiting invasive species' spread and creating conditions that favor less common, conservative species.

Prescribed Burns

Historically, prairies were maintained through regular fires ignited by lightning strikes or intentionally set by Native Americans. Fires played a vital role in controlling tree and brush growth while promoting the health and vigor of prairie plants. Prairie species have evolved to withstand fire, with below-ground growing points that allow for quick regrowth after a burn. In contrast, many non-native weedy species are not adapted to fire, resulting in their suppression or reduction in number after a burn. It can't be overstated how effective fire is at supporting native prairie species and eliminating non-native species.

The City of Middleton reintroduces fire to the prairies through prescribed burns. These controlled fires help suppress invasives, invigorate native vegetation, and maintain a healthy ecosystem. Regular prescribed burns aid in the restoration and maintenance of oak savannas like Fredricks' Hill or Bock Forest, which historically coexisted with prairies.  

Prairie restoration efforts at Pheasant Branch have made significant progress, but ongoing work is needed to combat invasives and reestablish oak savanna ecosystems. The removal of invasive seed sources from the prairie also prevents their spread to surrounding areas.

For more information on prairie restoration, including Wisconsin's prairies and helpful links for starting your own prairie, we recommend exploring these resources:

Pheasant Branch Conservancy Prairie History

Free Native Plants for Community Projects

WDNR Guide to Planting Native Species

UW-Madison Arboretem Native Plant Sale