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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

In the Garden: Choose flowers that can take the heat

Black-eyed Susans are perky, heat-tolerant perennials that attract pollinators. (Susan Mulvihill / The Spokesman-Review)

Remember when the peonies and rhododendrons were blooming this spring? I’m certain they wouldn’t care for this heat wave one bit. As our weather gets hot each summer, it would be a shame if there weren’t flowers for us to enjoy.

Fortunately, there are many annuals and perennials that can take the heat while adding color to our gardens.

Two of the toughest annuals I know are calendulas and zinnias. Calendulas are most known for their edible, bright orange or yellow flowers. I grew a dozen of them last year in a hot, dry spot in my yard. Where previous plantings had fried in the heat, these plants looked downright cheerful about their setting. This year, I discovered they had self-sowed. There are now about 30 plants blooming their hearts out.

Zinnias come in a variety of colors and heights, from 6-inch Thumbelina to 4-foot-tall California Giants. My favorites are hot-colored Persian Carpet, burnt-orange Zahara Double Fire and Profusion Cherry. In addition to looking fabulous in the garden, zinnias make wonderful cut flowers.

What about heat-loving perennials? There are plenty to choose from:

If you’re looking for some lovely pinks and purples, bee balm (Monarda) is an excellent choice. As you’d guess, they are bee magnets but hummingbirds love them, too. Hardy down to USDA zone 4, the plants reach 3 feet in height and the foliage has an appealing citrusy scent.

Black-eyed Susans (Rudbeckia) are truly a perennial favorite, and not just because of the name. If you look up “perky” in the dictionary, I’m certain you’ll find their photo right next to it. With black central disks and buttery-yellow petals, these plants brighten up the garden and don’t care how hot it gets. They are hardy down to zone 3, grow 2 to 3 feet tall and also make a nice cut flower.

Blanket flower (Gaillardia) comes in yellow, orange, red and combinations of all three. I like Fanfare, Arizona Apricot and Red Sun. Hardy down to zone 3, they typically reach about 2 feet. Bumblebees and butterflies love them.

Coneflowers (Echinacea) only used to be available in light purple or white, but plant breeders have been busily coming up with hybrids that are very popular with gardeners. It’s hard to choose but some of my favorites are Hot Papaya, Coconut Ice, Summer Sky and Cheyenne Spirit. Popular with bees, they are hardy down to zone 4 and grow 24 to 30 inches tall.

You might think it’s crazy to recommend a type of thistle, but globe thistle (Echinops) is very different from Canada thistle and has something special going for it: Finches find their seedheads irresistible during the fall and winter months. Plants grow 4 feet tall, are deer-resistant and hardy down to zone 3. In summer, they’re covered with spherical blue flowers that bees adore.

Russian sage (Perovskia) has an ethereal look to it, with its diminutive purple flowers and gray foliage. Blue Spires grows up to 4 feet while dwarf Lacy Blue stays below 2 feet. Appealing attributes include deer-resistance, attractive to bees, a lengthy blooming season and hardiness down to zone 4.

I’ve never seen a stonecrop (Sedum) wilt in the heat. Most gardeners are familiar with Autumn Joy but other captivating cultivars include Matrona, Firecracker and Lime Twister. Ranging from 6 inches to 2 feet in height, they are hardy down to zones 3 or 4.

When it comes to hot weather, all of these plants are far tougher than this gardener. Let them add color to your garden late in the season.

Susan Mulvihill is co-author, with Pat Munts, of “Northwest Gardener’s Handbook.” Contact her at and follow Susan on Facebook at