2015 was a big year for the Fremont Township Highway Department! After years of creatively cramming their equipment in buildings that were too small, they have a new building that efficiently holds their equipment and houses the CERT trailer and equipment. Now they can do their jobs quicker and safer and maintain their equipment better. Thanks to ordinances for water management, whenever a new impermeable surface (roof, street or parking lot) is added, the water run-off created by those surfaces must be handled on site. Fortunately the new building location sits adjacent to the lowest corner of the garden, a spot I had been eyeing as a potential native, pollinator friendly rain garden.
I was envisioning a native garden with loads of swamp milkweed and native flowers that support monarchs and other pollinators–an area teaming with life that would thrive in both wetter seasons and dry. By now most people understand that monarchs need milkweed to reproduce, but planting good nectar sources are also important.
This space would nurture our flying friends, but less obviously it would also nurture us! Not just visually, but also by cleaning the water that runs off the hwy dept ramp! Native plants have deep root systems that work as filters, cleaning the pollutants out of water that runs off of streets and rooftops. Certain native plants are well-suited for the varying levels of wetness that a rain garden in our zone will experience throughout our four seasons.
Having never installed a rain garden, I enlisted the help of Dave Eubanks, a professional ecologist with a passion for preservation and creating stable shorelines. Dave gave us pointers on developing the swale that will carry the water into the rain garden, adding rocks to slow the flow of water, sloping the sides of the depression and recommending two plant mixes to accommodate the different regions we have in the rain garden.
For the lowest region of the rain garden that may frequently hold water, he recommended a detention mix that includes grasses, sedges, rushes and forbs (flowers) that is well suited to “less than optimum growing conditions,” as the seed mix states.
Our second mix started halfway up the slope of the garden and covered the perimeter of the garden. This mix was labeled Wet Mesic Prairie for Clay Soils. This mix boasts big bluestem and gobs of prairie forbs that will be a sight to behold if they all show their faces!
After planning the location, size and depth of the garden, township personnel excavated the area, leaving a slab of clay at the bottom of the basin. While not at all an acceptable planting bed for most veggie plants and picky cultivated perennials, these native seeds should have no trouble busting through the clay to get established. On the day of seeding, the remaining water in the basin was pumped out to minimize standing water. Seed was spread by hand throughout the garden, with special care taken to frequent hand stirring the mix to keep the small seeds from sinking to the bottom of the bucket.
After the last seed was spread, erosion blankets were spread over the entire rain garden area and stapled in place with landscape staples. The erosion blanket holds the seeds and soil in place until they put down roots. Perennials take time to get established, often focusing all their efforts in developing roots in the first year. We hope to add some perennial plugs (newly started plants) in spring 2016 to speed up the process, add diversity and ensure certain species find a place in our garden.
2018 Rain garden update!
Every year we are seeing more plant diversity! Cup plant is an aggressive native that we will be limiting the spread by cutting spent flowers so they do not spread seed. Cattails are also spot treated with herbicides as they also tend to take over wet areas and preclude diversity.