The Garden Perennials of August

This August morning, like every morning since Mia the Beagle came into our lives in late July, she and I took a long walk up and down the dirt road that connects our home with the main road.  While she read the map of smells left during the night, I took stock of the roadside plants and the insects they attract.

With Mia straining at her long leash, urging me to keep walking,  I lingered for a minute at the end of the drive, watching insects foraging for nectar and pollen along a broad sweep of goldenrod, Queen Anne’s lace, and other wildflowers.  I think of this spot as part of Marjorie’s Garden, an insectary filled with native perennials and annuals, plants that in mid-August are crawling with bees, flies, wasps, and beetles.  I give this place credit for the abundance of pollinators in our vegetable garden.

My favorite of the native goldenrods, the elm-leaved goldenrod (foreground) with Joe Pye weed (left background) and sneezeweed.

Goldenrods are one of the many exuberant perennials growing in gardens along the coast of Maine in mid-August.  Several native species are commercially available, including one of my favorites, the elm-leaved goldenrod, Solidago ulmifolia, which comes into flower in late August.  It grows up to four feet tall with terminal clusters of yellow flowers borne on short outward-arching stems.  A plant in flower looks like a fireworks display.

The following is a listing of other August-flowering perennials, including some excellent plants for attracting pollinators.

Globe Thistle (Echinops ritro)

Globe thistle and purple coneflower flowering together

Native to Europe and Asia, globe thistle plants grow to 4 feet tall and 2 feet wide.  It is an essential plant for the pollinator garden.  All types of native bees and butterflies are drawn to the nectar produced by steel-blue flowers tightly packed in spherical clusters.  The thistle-like foliage is also attractive, each dark green leaf deeply lobed.

Globe thistle is also an excellent plant for the cutting garden.  Essentially problem free, the plants can be left undivided for years.

Orange Coneflower, Black-eyed Susan (Rudbeckia fulgida var. sulvantii ‘Goldsturm’)

Rudbeckia ‘Goldsturm’ is most effective when grown in mass plantings.

This long-blooming summer perennial has been a popular garden plant for decades.  A selection of a North American wildflower, it grows to 3 feet in height with an upright clump-forming habit.  The large daisy-like flowers (3 to 4 inches across) with deep yellow rays and dark brownish-black center disks are borne singly on stiff branching stems.

Rudbeckia ‘Goldsturm’ is most effective when massed in bold drifts, often with ornamental grasses.  The flowers can be cut for fresh arrangements, but plants should not be deadheaded as the black seed heads remain attractive through the winter and the seeds are taken by goldfinches and other small birds.

Purple Coneflower (Echinacea purpurea)

Purple coneflower has long been a favorite summer perennial.

Purple coneflowers have tall rigid stems bearing large, daisy-like flowers with slightly drooping, rose purple petals (ray flowers) and large, coppery-orange central cones.  They have a long summer bloom period, providing an abundance of cut flowers.  Goldfinches peck at the dried brown seed heads in winter.

Purple coneflowers are among the easiest perennials to grow.  Amending the soil with compost or other organic matter will provide essential nutrients for healthy growth.

Meadow Rue (Thalictrum rochebrunianum)

The open airy flowers of the lavender mist meadow rue stand in sharp contrast to mass plantings of rudbeckia and other bold perennials.

Blooming later than the columbine meadow rue (Thalictrum aquilegifolium), this species is our favorite. Growing to six feet in height, its tiny, pendulous, lavender-purple flowers with contrasting yellow stamens form a cloud of soft color and texture that floats above the garden bed, an effect that is enhanced in groups of three or more plants.  The blue-green foliage is a welcome addition to the garden throughout the summer.

Joe Pye Weed (Eutrochium purpureum)

Joe Pye weed (left) and sneezeweed (right)

Joe Pye weed is a mammoth clump-forming perennial, reaching up to 9 feet tall in rich, moist soils.  The species has loose clusters of small pink flowers, but many gardeners prefer the cultivar ‘Atropurpureum’ with violet purple flowers and dark burgundy stems.  Everything about this plant is bold, including the lance-shaped toothed leaves that form a dark green foil for early-blooming perennials.  Flowering from early August through early autumn, Joe pye weed is one of the best butterfly- and bee-attracting plants.

Sneezeweed (Helenium autumnale)

Sneezeweed can reach 6 feet or more in height and is just as wide when grown in rich, moist soils.  Its branched stems bear huge masses of 12-inch flowers in August and September.  The common name has nothing to do with the plant’s pollen, but can be traced to the use of the dried and powdered leaves as a snuff to cure the common cold.

Sneezeweed is another example of a native North American plant that was not popular in gardens until European breeders worked with them.  Now there are several varieties in flower colors of gold, orange, rust, and red.  A mix of gold and red heleniums creates a bright and cheerful garden scene.

Oxeye Sunflower, False Sunflower (Heliopsis helianthoides)

Heleniums are among the most colorful of summer perennials.

Another great eastern North American plant for the pollinator garden and cutting garden, the oxeye sunflower is closely related to true sunflowers.  Plants grow from 3 to 6 feel tall.
The blooms, ranging from 2 to 3 inches across, are orange-yellow with dark brown centers.  They make long-lasting cut flowers.

 

 
Swamp Milkweed (Asclepias incarnata)

Swamp milkweed is a pollinator magnet in the August garden.

This erect, clump-forming perennial grows 3 to 4 feet tall.   In midsummer, the pink to mauve flowers attract bees, butterflies, and other beneficial insects.  In addition, swamp milkweed is an important larval host for the monarch butterfly.

The flowers are followed in late summer by attractive 4-inch-long seed pods.  At maturity, these pods split open to release their silky-haired seeds to the wind.

Although native to swamps and wet meadows in most of the U.S., swamp milkweed is surprisingly tolerant of average well-drained soils.  It has a deep taproot and is best left undisturbed once established.

Gayfeather, Blazing Star (Liatris spicata)

Liatris spicata, gayfeather, is a “must have” plant for the pollinator garden.

Native to meadows and the edges of marshes in the eastern U.S., gayfeather is an upright, clump-forming plant growing to 4 feet tall in cultivation.  Terminal spikes of deep purple flowers are borne atop erect, leafy stalks that arise from basal tufts of grass-like leaves.

Gayfeather attracts native bees, including bumblebees, as well as butterflies and hummingbirds.

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About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)