If I had it to do over again:
I was a pioneer in 1998 when I began to plant my prairie gardens in my small- 50’ x 120’- city corner lot,. My gardens are mostly all linear , arranged on both sides of the public sidewalks, along the edge and side of my back yard and along the perimeter of my house and garage. The only exception is my island garden in the center of my back yard on the other side of the garage.
My gardens are bountiful beyond measure and I enjoy them every single day. They attract a myriad of bees and butterflies, and to a lesser extent, birds. Their deep root systems infiltrate rain water deep into the earth and the shallow aquifer. And it says “Midwest” rather than England or East Coast.
But there are a few plants that are far too aggressive for the small garden.
Here’s my list:
Any of the Woodland Sunflowers: Helianthus divaricatus, H. strumosus, and H. hirsutus).
I planted H. strumosus and while it mingled beautifully with Joe Pye Weed in my savanna garden for several years, one year it went viral, eating up everything in its path, including an American Hazelnut (Corylus americana). Even worse, I planted it in savanna gardens of a few clients and it is a dreadful problem there, as well.
These three silphium, relatives of sunflowers: Rosin Weed (Silphium integrifolium), Cup Plant (S. perfoliatum), and Compass Plant (S. laciniatum).
I love these plants and love to tell their stories, especially to children, but they spread vigorously and are far too aggressive for small home gardens.
Only growing 2-3’ tall in the crowded prairie, Rosin Weed grows over my head in my gardens. It has fibrous roots that form colonies from short rhizomes. it also increases by seed.
Compass Plant does indeed act as a compass–its leaves tend to pointnorth and south. The flowers, like sunflowers, follow the sun, facing east and west. It has a deep central taproot 8-15’ deep, but it also has shallow rhizomes that allow it to establish colonies. That is what has happened here. The leaves have since collapsed and it has only produced one flowering stalk. It’s no longer attractive or interesting, but perhaps the clonal growth can be moved or just simply pulled out. Does anyone have any suggestions?
One year, Cup Plant just showed up in my yard. A seed must have hitch-hiked its way to my garden via another plant that I had purchased. Again, it’s an attractive and interesting plant, but too aggressive for the small home garden. It has spreading fibrous roots that form colonies and, in addition, it seeds itself with abandon. I find dozens of new plants throughout my gardens every year that I have to dig up.
My favorite, Prairie Dock, (S. terebinthinaceum) is less aggressive and I do recommend that everyone plant one of these as a focal point or specimen.
Tall grasses: Big Bluestem (Andropogon gerardi ), Indian Grass (Sorghastrum nutans), and Switch Grass (Panicum virgatum). All of these grasses add so much grace and beauty to a garden, but then they pop up everywhere, crowding out other less aggressive plants.
Here are a few more aggressive plants, but I wouldn’t be without them.
Stiff Coreopsis (Coreopsis palmata) in nature is found in dry prairies, sand prairies, and gravelly hill prairies. Put it in mesic or garden soil and it kicks up its heels, shouts “Hooray” and takes over. Knowing its characteristics, I didn’t plant it into my garden until the other plants were mature, but it just laughed and took over anyway. It blooms at the same time as Butterfly Weed and Pale Purple Coneflower, creating an exquisite combination.
Stiff Coreopsis becomes a solid patch in my garden.
In Horlock Hill Prairie, it has lots of competition.
Sometimes in just the right place, here with self sown Cup Plant next to my house.
Or here where it peeks into a window. My east-facing studio window frames Joe Pye Weed along with Virgin’s Bower (Clematis virginiana).
Or is this worth having a lot of self-seeded Joe Pye Weed around?
Do you have native plants you wished you hadn’t planted?