Five Elegant Perennials for the Summer Landscape

Lately, I have been watching old Western films.  John Wayne always looks so calm and collected.  He never sweats, even though he is wearing five layers of clothing.  Have you ever wondered why they wear so much when it is so hot?

Right now, I wish I had a sprinkler to run through or a bucket of ice water to dump on myself.  Those movie characters who ride through the desert unscathed remind me of some tough plants blooming right now in the arboretum.  It is a true testament to the toughness of some perennials that thrive in adverse conditions.

Try these sun-loving perennials – you will be rewarded year after year by these resilient plants:


Letterman’s Ironplant-Vernonia lettermanii ‘Iron Butterfly’

While walking through the gardens this morning, I noticed the vibrant purple blooms of this iron-clad wildflower.  We should be tooting the horn for more natives like these.  The plants were alive with activity-like a pollinator magnet!  Each stem has slender leaves radiating outward, similar to Amsonia hubrichtii.  This is a more refined ironweed, but just as tenacious as the pasture type.  I use them in groupings with switch grass and goldenrods but they would be a nice addition to any landscape.

Vernonia Iron Butterfly

Photo taken at Dyck Arboretum of the Plains

 


Russian Sage-Perovskia atriplicifolia

On my recent trip to Denver, Russian Sage was ubiquitous.  That’s a fancy word for everywhere.  It was in the street medians, parks, store fronts, and in front of most homes, but for good reason.  The soft lavender blooms are eye-catching.  The cloud of colorful flowers above the finely textured aromatic foliage is a wonderful combination.  Did I mention that Russian Sage is tough?  It shines in any full to part sun location.  It can survive drought conditions, but appreciates weekly watering.  They are best displayed in mass plantings or with native grasses.

Russian Sage-Photo Courtesy of Walters Gardens, Inc.

Photo courtesy of Walters Gardens

 


Button Blazing Star-Liatris aspera

Blazing stars have put on quite a show this year and button blazing star is no exception.  It is in full bloom right now in 100 degree heat and loving it.  The entire plant matures to 3′ in height, but the real show is the purple button flowers that develop along the stem.  It is happiest in medium to dry soil conditions and will become unhappy with too much moisture.  Pollinators flock to it, including butterflies, hummingbirds, and bees.  Plant them in mass, 8-12 inches apart for the ultimate display.  I like to integrate several grasses like Little Bluestem or switch grass to give interest later in the season.

Liatris aspera

Photo taken at Dyck Arboretum of the Plains

 


Hummingbird Mint- Agastache ‘Blue Boa’

This plant has been one of my biggest surprises over the last several years.  It is almost always in bloom.  It loves the heat and humidity.  The deep violet-blue blooms lure many different pollinators and ‘Blue boa’ requires very little care once established in a medium to dry location.  If you want to help the pollinators, try a few in your landscape. You will be surprised by them, too.

Agastache Blue Boa-Photo Courtesy of Terra Nova Nurseries

Photo courtesy of Terra Nova Nurseries

 


Aromatic Aster-Aster oblongifolius ‘October Skies’

We have been growing this great form of our native aromatic aster for several years.  It is not rambunctious in the landscape.  In fact, it develops into a nice bush that is covered with glowing lavender flowers.  When the whole plant is in bloom it looks like a mum on steroids.  Flowers begin to open in late September and last into October.  During the warm days of autumn, pollinators congregate on these beauties, seeking to collect the last pollen of the season.  We have used them in borders and native groupings with ornamental grasses.

Aster October Skies

Photo taken at Dyck Arboretum of the Plains

 

Notice the theme?  They all have lavender blooms.  These are a few plants that are doing well in the arboretum.  What plants have you had success with this year?

Denver Botanical Gardens Trip

On a recent trip to the Rocky Mountains, I visited the Denver Botanical Gardens. My family rolls their eyes because we always visit some garden while on vacation. They usually have a good time once they are there but their short attention span makes me hustle through the gardens. Anyway, I noticed some interesting native plant displays that I want to try at the arboretum.

Denver Botanical GardensUnder some cottonwood trees were strategically placed shorter native plants. Essentially, they were mimicking a savanna landscape which is the transition zone between open prairie and forest.

The plantings were diverse with grasses and perennials. One of the many things that caught my eyes was how the plants were grouped. It made such a visual impact. Blooming perennials popped while the grasses offered texture and soft forms that blended the planting together. A small trail weaved its way through the entire landscape allowing visitors to get up close to the plants.

The grasses they used were blue grama, little bluestem, side oats, and prairie dropseed. The wildflowers included purple poppy mallow, four o’ clocks, columnar coneflower, penstemons, coneflowers, indigos, asters, blazing stars and goldenrods.
This display is totally scalable. By grouping at least five plants of a particular species together, they stood out in the garden. The grasses were used to line the path and edges but also were used as a backdrop to highlight the blooms and seed heads of the wildflowers. Grouping these individual species together makes it easier to weed, water and maintain.

We have been experimenting with this group approach at the arboretum with great success. A limited palette of wildflowers that bloom at different times of the year combined with grasses in artistic ways can have a tremendous visual impact.

Try spring bloomers next to those summer or fall blooming perennials. A little forethought before planting, matching the plants with your site, grouping species together, properly planting and establishing will go a long way to creating the effect you want in your landscape. I have found with natives that “less is more”.

What plants or landscapes have you seen in summer travels that you would like to try?