Cannon Township rain gardens
6878 Belding Road NE, Rockford
This site, with rain gardens, vegetated swales, and native plant restoration, was designed by Nativescape LLC. It is located in the Rogue River watershed, a tributary of the Grand River.
Cannon Township, an innovative community of great natural beauty, desired to create rain gardens and native landscape areas at their newly designed township hall. They wanted to have an attractive demonstration of low impact natural landscaping that protects water resources and enhances wildlife habitat. Cannon Township can be counted on to do something wonderful that sets an example for the rest of us.
Benefits of Natural Landscaping
Native landscaping has many benefits, such as greatly reduced costs of landscape maintenance, natural beauty, water quality protection, enhanced habitat for wildlife, reduced noise pollution, cooler local summer temperatures, reduced soil erosion, enhanced property and real estate values, more liveable communities; the list of advantages is endless.
Three rain gardens
Three rain gardens were planned, with an infiltration swale in the new parking lot. Other areas were to be both seeded and plugged with native perennials instead of prepared with a traditional, irrigated, high maintenance turfgrass.
Long before the site was graded and planted, we tested the soil, which is a sandy loam, by digging a hole and pouring in a bucket of water. Infiltration was very fast. In a matter of minutes, the 
However, after the lot was graded by heavy equipment, infiltration was severely compromised. We were told that "the plants would do the magic", and infiltration would improve after the plants mature.
Unfortunately, it takes several years for plants to improve infiltration, especially since it takes longer to get plants established in compacted soils. This site is now an experiment in finding out exactly how long it takes the plants to "do the magic". This is the second year, and infiltration is still poor to nonexistant.
Lessons learned;
Soil preparation and project staging are key to success.
If the soil is properly prepared and is not compacted by heavy equipment, the plants get a better start and rain gardens will infiltrate even before the plants are there. This reinforces to us that proper soil preparation is absolutely essential to the function of a rain garden.
Mistakes are often opportunities in disguise!
One of the rain gardens never dries up. Deer come there to drink, dragonflies abound, and tadpoles thrive in this small pond. We saw this not as a failure, but as an opportunity. Cannon Township could use this area to educate the community on the many delights of small wetlands and ponds in creating wildlife habitat and increasing ecological diversity. With the addition of an interpretive sign and an observation deck and placement of emergent wetland plants, the township grounds would become a desireable place for schools to visit for field trips.
Competing vegetation should be removed.
Site preparation should include eradication of existing, competing, non-native vegetation and seed banks, and can take a year or more to accomplish, PRIOR to planting. This site had quack grass (Agropyron repens or Elymus repens) and spotted knapweed (Centauria maculosa). Grading and planting were done in the same season, with no removal of invasive non-natives. The native seed and plants are competing with these and other introduced invasives. At this time, the native plant areas are being mowed to reduce competition from the invasives. Burning might also be helpful.
Be sure to include three years of site maintenance to insure success.
Site management for this kind of installation should include a three year management contract to insure success of the native plants. It takes three years to establish a native planting. This does not include the time taken to eradicate existing vegetation.