By Marty Ross
When the summer heat is on in the Midwest, I’m glad I am not a plant out there in the sun, but a lot of flowers don’t seem to mind a bit. Annual flowers in particular bloom right through summer’s torrid temperatures. They make a garden look wonderful even when it’s too hot to do much gardening.
Zinnias are at the top of my list of heat-wave-tolerant flowers. I grow old-fashioned zinnias every summer in full sun in my community garden plot, and they provide flowers for bouquets from June through October. To keep them blooming without stopping, I pick zinnias every week. As my friend Lisa taught me, “You have to cut them every week, whether you want them or not.” When I have more than I really need, my neighbors always appreciate a colorful bouquet.
Cosmos also blooms tirelessly through heat and drought, and stands up to hard rain, and wind too. Silky-petal orange cosmos grows tall and produces innumerable flowers on sturdy branching plants. Pink, white, and magenta cosmos have feathery foliage and look too delicate for brutal summer temperatures. But they bloom vigorously in the heat and are very cheerful in bouquets. Kids just love cosmos and zinnias.
Butterfly milkweed (Asclepias tuberosa) is a perennial with bright, long-lasting flowers and pretty seedpods. The pods teem with seeds, each attached to a wispy, silken strand that catches the wind and wafts the seed away. In my garden butterfly milkweed blooms two or three times during the summer. Each time the flowers attract butterflies and other pollinators. Late in the summer I always find beautiful caterpillars feasting on the leaves. Butterfly milkweed is the only food eaten by monarch butterfly larvae (the colorful striped caterpillars); when you grow it, you’re growing butterflies too.
Bee balm (Monarda) can be too aggressive in a flowerbed, where it spreads by underground runners. But it is a terrific, long-blooming, heat-tolerant perennial to grow in a sunny spot where it doesn’t crowd out other plants. Hummingbirds love it. Bee balm also attracts butterflies, bees, and other pollinators. (Don’t worry about the bees, they’re interested in the nectar, not in you!) Bee balm looks pretty in a meadow garden with black-eyed Susans, and shows up nicely against a garden shed or garage. Deadheading the plants (you can use hedge shears on them) prolongs their bloom season.
Blackberry lily (Belamcanda chinensis or Iris domestica) has glowing, orange-freckle flowers on stems 3 or 4 ft tall. I grow it as much for the blooms as its attractive, spiked leaves (which look like iris leaves), and for the shiny black seedpods from which it gets its name. These old-fashioned flowers start to bloom in midsummer and keep going for weeks, in sun or part shade. They reseed freely without becoming aggressive. Blackberry lily is one of my favorite pass-along plants.
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