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| Liatris pycnostachya (purple bloom), Pycnanthemum muticum (upper right foliage), Symphyotrichum laterflorus (dark purple foliage in foreground) |
What’s Blooming in August: The Prairie Garden
by Bryan Fischer,
Horticulturist, The Gardens on Spring Creek
While the “dog days” of summer represent a
quiet time in many gardens in our region, emblemized by plants that brown-out
or resort to a scorched, stupor-like state of semi-dormancy, these hot
days usher in the fashionably-late arrival for the bloom of
many prairie natives. Thriving off warm nights, which take longer to arrive
here on the Front Range than in much of the Midwest due to our elevation, the
residents of our Prairie Garden have finally made their gaudy entrance onto the
scene.
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| Guara lindheimer and Artemisia frigida |
Perhaps the first arrival this year from the late season bloomers in the Prairie Garden, Oenothera (Gaura) lindheimer (commonly called just gaura or bee blossom) has been dazzling for weeks, creating an almost celestial haze of hundreds of small, white, four-petaled flowers along the length of three-foot stems. These seem to float in front of the sleek, silver Artimesia frigida (fringed sage) and fine-textured prairie grasses in the central part of the Prairie.
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| Oenothera guara (Guara biennis) and Salvia azurea 'NeKan' |
Two other Oenothera species
have been contributing to the show – the first being O. rhombipetala, a
Nebraskan Sand Hills native with electric yellow blooms that
reaches almost four feet tall and nearly as wide, which is paired with cobalt
blue Lobelia siphilitica (great blue lobelia). The second Oenothera to watch for would be the massive
but ephemeral, Oenothera gaura (Gaura biennis), a heavy blooming, white-pink flowered gaura that stands nearly seven feet tall in the center of the garden’s tall grass spine. Both of these plants are best seen at opening,
as their delicate petals are designed to be pollinated at dawn or dusk and wilt
by midday. These wilted petals will be replaced by a fresh crop daily.
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| Eryngium yuccifolium and Liatris ligulistylus |
Arguably the belle of the ball, Liatris ligulistylus (a tongue twister of a name, I know) has begun to flower in earnest. Found in two main stands in our Prairie, this “Rocky Mountain blazing star” produces buttons of fuzzy looking, pink-mauve flowers along four-inch stems. This is, by far, the plant that pulls the most butterflies to my garden, and usually at least one monarch can be seen swirling around the plants at any given moment by midday.
While its common name, rattlesnake master, would suggest otherwise, a substantial stand of Eryngium yuccifolium makes a delightful companion to the main stand of Liatris. Waxy, blue-tinged and slender foliage below dozens of white orbs help to compliment the very different color and shape of the blazing star plants. Bees and pollinating wasps prefer the rattlesnake master which is, thankfully, not adjacent to the path.
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| Vernonia fasiculata and Rudbeckia triloba 'Prairie Glow' |
One of my favorite combinations in the garden
at present is a very Halloween-y orange-purple duo: the biennial, airy orange Rudbeckia triloba 'Prairie Glow' with a hearty mix of
two purples. The first of these was one of only two ironweeds native to the
Front Range, known as Vernonia fasiculata
that provides umbrella-shaped, fuzzy purple compound flowers on tall, swaying
stems, and the previously mentioned, spike-shaped Liatris ligulistylus. I
selected these two species to sustain the color combination for the duration of
the Rudbeckia’s bloom – with Veronia’s
exciting royal purple blooms earlier in the season and the lighter purple Liatris providing a longer season of bloom and keeping the vignette
interesting for weeks.
This garden will soon have a handful of other vignettes peaking. Keep an eye out for aptly named Salvia azurea (azure sage) mixed in with spreading yellow Solidago rigida ‘Fireworks’ (goldenrod), as well as a second hearty display of yellow and purple from an annual selection of Rudbeckia (black-eyed Susan) with the Texas native Salvia farinacea (mealy-cup sage). Asters, notably the refined, purple Symphyotrichum oblongifolium is just beginning to break bud, along with the dark and moody Symphyotrichum lateriflorum ‘Lady in Black’ . These busy perennials will be among the last flowers in this space, with some blooming through September and into October in a good year.
Only after hard frosts force these plants to
stop blooming will the Prairie Garden call it a
night. In the meantime, don’t hesitate
to stop by the gardens and make the trek out to enjoy the spectacle! It won’t disappoint.