Perennial Winners and Losers in the Sidewalk Border
The Sidewalk Border was the second border that I added to the garden. We moved into our house in July, 2003. Next day I went to work on the Driveway Border. The following spring I started digging up turf along the sidewalk for the Sidewalk Border.
This border has fairly moist soil, as water drains down from the house towards the sidewalk, and enjoys almost full sun. The soil is rich and loamy.
The plant mix in this border has changed substantially over the years. Some of the changes were mine, others were made by the plants themselves. Here’s an overview.
Blue Star (Amsonia tabernaemontana). Anchors the west end of the border. A slow and steady grower that forms a massive clump.
Rose Milkweed (Asclepias incarnata). A tall Milkweed that seems to hold its own with the Monardas.
Northern Sea Oats (Chasmanthium latifolium). A constant struggle to keep this grass from seeding itself all over, but oh those dangling seed heads!
Wild Geranium (Geranium maculatum). Short and neat, I planted it in the front of the border along the sidewalk. Then I tried to repeal and replace it with various Salvias. The Geraniums chuckled at my presumption and grew right back from whatever bits and pieces of rhizome remained. They were perfectly happy in the shade cast by the Switchgrass, Monardas, and other taller plants.
Bee Balm ‘Raspberry Wine’ (Monarda didyma). I planted a couple of these guys on a whim and now they almost dominate the look of this border for most of the summer.
Wild Bergamot (Monarda fistulosa). Not as aggressive as Bee Balm, but can hold its own. The lavender blue flowers are a good contrast for ‘Raspberry Wine’.
Switchgrass (Panicum virgatum). Over time it made huge clumps at the back of the border. Early this year I divided two of those clumps for the first time. As the Switchgrass expands it tends to squeeze out smaller plants, but more on that below.
Brown-Eyed Susan (Rudbeckia triloba). Showed up here without an invitation, but that’s OK. Always disappearing, then popping up somewhere new.
Celandine Poppy (Stylophorum diphyllum). Shares the front of the border with the Wild Geranium.
Short’s Aster (Symphyotrichum shortii). A plant that takes care of itself, and provides a multitude of light blue flowers in fall.
Anise Hyssop (Agastache foeniculum). Love this plant, but it just doesn’t want to grow here. Can’t handle the tall competitors, plus maybe too much moisture. Fortunately, it grows well in the Driveway Border.
Smooth Penstemon (Penstemon digitalis). I have both the species and ‘Husker’s Red’. Initially it did well planted between clumps of Switchgrass. However, the Penstemon had to be transplanted as the expanding Switchgrass threatened to squeeze them out.
Early Sunflower (Heliopsis helianthoides). I just didn’t love this plant enough to justify the time needed to control its self-sowing. I thought the flowers were too coarse and stiff. Actually, I’m still pulling out Early Sunflower seedlings from this border.
Salvias, various (Salvia sylvestris ‘May Night’ and others). So I was inspired by the Lurie Garden’s River of Salvia and thought I could come up with a miniature version, a sort of Puddle of Salvia. Unfortunately, the Salvias struggled in the shade cast by taller neighbors. I ended up transplanting them, mostly to the Parkway Bed.
Golden Alexander (Zizia aurea). Golden Alexander prospered in the Sidewalk Border for the first few years, but eventually it was squeezed out by the Monardas. It continues to do well elsewhere, in spots where the competition is less intense.
TO BE DETERMINED
Last year I planted a number of ‘Casa Blanca’ and ‘Conca d’Or’ Lilies. They bloomed nicely this year, and we’ll see if they make themselves at home. I also planted a Wild Senna (Senna hebecarpa). It’s been settling in, but didn’t bloom this year. We’ll see how it does.
I’d like to add some blue to all the mid-summer red and pink in this border. Possibly some Blue Vervain (Verbena hastata). Also, in late summer the Wild Geranium tends to die back a bit, making the front of the border look a little sparse. I was thinking of providing some late season fullness and color by interplanting some Bottle Gentian (Gentiana andewsii) among the Wild Geranium.
The Sidewalk Border gave me an object lesson on companion plantings. Now when I think about combining plants, I try to anticipate which plants will shade or squeeze out the others over time. Smaller plants need to be shade-tolerant or carefully placed facing west or south so that they get adequate sun. They also need to be stubborn. Some plants just have a limited tolerance for competition.
That’s all for now.