Don't miss out on summer's best perennial.

Pink Phlox Growing
Credit: Steve Bender

These are the days that try a gardener's soul. It's hot and humid, it hardly ever rains, and most plants look like you laid them on a griddle. Be stout of heart, though. There's one perennial looking great right now – summer phlox.

Native to the eastern and central U.S., summer phlox (Phlox paniculata) should be a mainstay of every summer border. It comes in just about every imaginable color, blooms for a long time, makes good cut flowers, is easy to grow and propagate, and is a favorite nectar source for butterflies and hummingbirds. Blooms of many selections are fragrant. The only negative feature -- powdery mildew that blankets leaves with white fungus – has been conquered. Selections that I'll mention here resist it.

Pink Phlox Bloom
Credit: Steve Bender

Summer phlox forms a multi-stemmed clump that ranges in height from 1 to 5 feet, depending on the selection. This means you can place it in the front, middle, or back of the border. It goes well with daylilies, black-eyed Susan, purple coneflower, Shasta daisy, bee balm, goldenrod, and many other perennials and annuals. It likes moist, fertile, well-drained soil and full to part sun. Mulch it in spring to keep the soil moist and cool in summer. Keeping it too dry stresses the plant, making it prone to spider mites and mildew.

Purple Phlox Blooms
Credit: Steve Bender

Once you have one summer phlox, you'll undoubtedly want more. To get them, divide the clumps in early spring or fall. Or let them go to seed. Seedlings may be a different color than their parent, but I like surprises. If you don't want seedlings, clip off spent flower heads. This usually results in more flowers in a couple of weeks.

Grumpy's Top Ten

The following mildew-resistant selections will provide you weeks of color and joy. If you can't find them in your garden center, Perennial Pleasures Nursery and Bluestone Perennials are good online sources.

‘Blue Spot' – hyacinth-blue with white center, 36" tall, heavy bloomer

‘David' – pure white; 36-48"; very fragrant; the best white

‘Dodo Hanbury Forbes' – peach-salmon; 24-48", fragrant

‘Eva Cullum' – rose-pink with darker eye; 24-36"; fragrant

‘Jeana' —lavender pink flowers are smaller than normal, but filled with nectar; best selection for butterflies; 36-48"; fragrant

‘Katherine' – lavender-blue with white center; 24-36"; very fragrant

‘Laura' – deep purple with white eye; 36"; fragrant

‘Nicky' – striking magenta-purple; 30-36"; fragrant

‘Robert Poore' – purple flowers close in color to the old purple phlox your Grandma had; 48-60"; very fragrant

‘Sandra' – scarlet-orange with magenta eye; 24"; fragrant