When it rains at Whittier, the run off drains into Lake of the Isles and then through the chain of lakes and into Minnehaha Creek. This rain water carries with it all of the pollutants from cars and other sources and deposits them directly into Lake of the Isles. Here at the alley just east of the Amur Maple tree, the compacted soil was doing nothing to stop rain water from running off into the street. We created a simple, prototype rain garden to help stop some of this run off and filter it directly into the ground on site, while at the same time creating healthy soil and pollinator habitat. What was a wasteland ecologically, has now become an oasis for butterflies and bees!
When we dug into the compacted soil near the alley along 27th Street, we noticed something. Or rather, we noticed something was lacking....WORMS! There wasn't a single worm in the soil as we sifted through it. This plot has been a grassy area since the house here was torn down to make way for Whittier School in 1997.
A lack of worms is a sign of distressed soil. So we added some compost and good, black soil from the Pollinator Gardens. We dug a gracefully curving sunken garden with rocks along the edges to clearly delineate the garden. And we planted! Bee Balm, Black Eyed Susans, and Purple Coneflower - all MN native species that are attractive to pollinators.
Now, when it rains, the water sinks gently down into healthy soil and
Let's put on our skeptics hat. Won't the garden just become weed-ridden and neglected, as so often happens with school gardens? We've made a plan for that. First of all, all of the species here are native Minnesota species. They are meant to grow wild. So yes, even if the school community isn't able to weed and water the garden, these hearty species will establish themselves and continue to provide habitat services to birds and pollinators. They may look a little unkept, but they will be inviting to critical pollinator species nonetheless. Secondly, we plan to plan a tamarack tree on the nortern edge of the garden. Tamaracks are water loving trees, so this sunken garden is a boon. The tree would gradually grow to 30 ft or more and provide shade for the rain garden. With shadier conditions, a woodland type habitat will develop, with fewer weeds and natural beauty even if the garden is neglected.
To help our friends at facilities who will be mowing this area, we set into place large rocks that clearly delineate the rain garden from the mown areas around it.
This garden is a simple prototype. It isn't a full rain garden with underground cistern to capture all of the storm water. In a large storm event, the garden will fill and rain will spill over into the alley. Eventually, if funding becomes available, the garden could be expanded upon with cistern capacity added.
Many thanks to Minneapolis Community Education for funding Whittier's new Alley Rain Garden!
All of our Alley Rain Garden plants are native Minnesota species. They are drought resistant and pollinator friendly.