Select perennials that beat the heat
The excessive heat we've experienced lately has some perennials showing signs of stress. Choosing summer-blooming perennials that, once established, not only tolerate heat but thrive in hot, dry conditions will keep your landscape bursting with color during the hottest summers.
Yarrows begin to flower in June and continue throughout the summer if spent flowers are deadheaded. They are extremely hardy and thrive in average, well-drained soil. Their flowers - held in clusters to form large, flat heads - can be white, pink, yellow, lavender, orange or red. Some of the older varieties had lax stems that sometimes flopped under the weight of the flowers. Look for newer varieties with strong stems that never need staking.
Perennial salvias also begin blooming in early summer. They produce an abundance of flower spikes in shades of rose, blue and purple and range in height from 15 inches to 3 feet. If plants are pruned after the first flush of flowers, they'll reward gardeners with a bonus round of blooms. Salvias are gorgeous when planted in mass and make the yellow or bright pink flowers of companions pop.
Blanket flowers bloom heaviest in June, but continue to bloom sporadically into September. Their flowers are brightly colored daisies in combinations of red, orange and yellow. Plant these near the front of the border or in containers.
In July, the bright orange flowers of butterfly weed begin to bloom. A North American native, it attracts butterflies and bees and naturalizes easily in a well-drained, hot and sunny spot in the garden. The flowers can also be cut for floral arrangements, and the seedpods that follow work well in dried arrangements.
Butterfly weed is late to break dormancy in the spring. It may be wise to mark its spot so you don't accidentally cultivate it out during a late spring clean up.
Sedum, or stonecrop, is a star in the hot, dry garden. There are many varieties to choose from - some low-growing types perfect for rock gardens, edging or spilling over the edge of a rock wall; some taller varieties that combine nicely with coneflowers, black-eyed Susans and ornamental grasses.
Sedums have starlike flowers and succulent stems and leaves. Flowers may be yellow, white, pink or mauve. Foliage may be green, blue, bronze or reddish-purple.
Coneflowers and black-eyed Susans are both popular daisy-flowered perennials that are heat and drought tolerant. They both begin flowering in mid summer and continue until frost. What would a summer garden be without them?
Russian sage blooms at the same time as coneflowers and black-eyed Susans and look fabulous when planted alongside. The tall, airy stature of Russian sage contrasts nicely with its neighbor's coarse texture. The small flowers of Russian sage are a soft violet-blue. The foliage is gray and very fragrant.
When the temperatures remain high and rainfall is low, we may have to head inside for some air conditioning, but our borders will remain lush and lovely with perennials that beat the heat.
• Diana Stoll is a horticulturist and the garden center manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield. Call (630) 293-1040, Ext. 2, or visit planterspalette.com.