I didn’t know what I was getting into when I bought a tiny cup plant plug six years ago from Seed Savers Exchange. I thought that it was cool that they were selling Midwestern prairie plants in addition to their wide array of vegetable starts, so I got the cup plant, a prairie blazing star, and a purple prairie clover to plant in my then-new front yard. The prairie blazing star blends right in with everything else; it’s fine but not spectacular. It’s kind of floppy and looks rather shag dog by summer’s end; it’s also a dime a dozen in Chicago’s landscaped environs so doesn’t offer much in terms of rarity. The purple prairie clover is still one of my favorite plants. Its tutu-like purple flowers are dazzling when they bloom in July, and the plant is almost never seen around the city. But I fear that my own purple prairie clover is forever stunted by the dry conditions in my urban front yard; the plant still takes up barely ¼ square foot of space and is therefore easily overlooked in favor of more imposing species. Like Silphium perfoliatum, more commonly known as cup plant.
Imposing and aggressive it is. At 10 feet tall, the cup plant easily grabs your attention over other plants. Each spring, when cup plants crop up all over my yard and my neighbor’s yard and who knows where else, its aggressiveness kind of irks me. I’ve given cup plant seedlings away and walked away feeling rather coy. Will the new owner curse me in two years’ time the way that I have cursed my own endless cup plant supply? Or will they be able to hang in there — weeding it out where it isn’t wanted — and appreciate the magic it brings to the landscape? Even though it can be a pain in the ass, in the late summer days of the Midwest, the cup plant has no equal.
The cup plant holds water in its leaves, which form a cup where they meet the sturdy stalk. This is an incredibly useful feature for birds and butterflies, who sometimes find water in short supply, especially water that is high up and out of their predators’ reach. Today, for instance, is generally hot, muggy, and dry, but we did get a little rain last night. Leave it to the cup plant to save that precious rain for our thirsty friends. And those same water-holding leaves also provide protection from the hot mid-day sun, serving as a quasi-umbrella for small birds or bugs when the heat is too much.
The cup plant is opportunistic. It leaps out of the cracks between our front yard and the sidewalk and flowers prolifically even when squashed between my neighbor’s chain link fence and our gangway. Provided it has some sun and space, the cup plant will do well. It has deep roots and is incredibly drought tolerant. Never has it been on my laundry list of garden chores to “water the dear old cup plant.”
All of this is well and true, and I do so appreciate the cup plant for all of it. But my favorite thing about the cup plant is something that makes me tear up as only a handful of things in the garden will: winter’s first snowdrops perking their heads up beneath 18 inches of slush, strawberries ripening when the robins were busy looking the other way, hips following roses on a buxom Rugosa rose, and the unmistakable high-pitched song of goldfinches visiting the cup plant at 3 o’clock every afternoon. I suppose it’s their early bird happy hour. As my friend Craig once commented, “It’s their beer and peanuts,” with the beer being the stored-up water in the leaves and the peanuts, the large flower seeds. Our cup plant has hosted a pair of goldfinch couples every late summer for years now: two stunning gold yellow males and two subtly brown-yellow females. Their song and their presence stops me in my tracks each afternoon and reminds me why I planted a garden in the first place, to give something to others and in so doing, to myself.