Outstanding Perennials for Landscape Success

A picture of Allium 'Millennium'

The pace of new perennial introductions by plant explorers and breeders each year is almost staggering.  What is a herbaceous perennial enthusiast to do?  Is NEW always improved? How does the “latest and greatest” compare to the traditional tried and true?

By Bill Ruppert, photos courtesy Walters Gardens, Inc., www.perennialresource,com unless otherwise credited.

[An abbreviated version of this article appeared in The Gateway Gardener June 2014 issue.]

The pace of new perennial introductions by plant explorers and breeders each year is almost staggering.  What is a herbaceous perennial enthusiast to do?  Is NEW always improved? How does the “latest and greatest” compare to the traditional tried and true?

As both an avid home gardener and professional in the field of wholesale horticultural plant sales and marketing, I enjoy the opportunity to learn about and trial cutting edge plants in my Kirkwood garden.  I also value a wonderful relationship with artisan landscape designers and landscape architects to promote the best-of-the-best perennial plants for both high profile institutional landscapes and unique residential gardens.  These professionally designed landscapes expand opportunities for personal examination of perennials growing beyond my personal garden.

In addition to experiencing these plants “in-action” at both residential and institutional landscape sites, I also collaborate with my team of plant propagation suppliers to distribute new and under utilized perennials to botanical institutions of our region to include with their plant trials and exhibits.  During the spring of 2014, we distributed 38 new and under utilized perennial selections to the Missouri Botanical Garden (Kemper Gardens), St. Louis Community College Meramec Horticulture Learning Gardens, Mizzou Botanic Garden (at the University of Missouri in Columbia), and Powell Gardens (Kansas City’s botanical garden).  The following perennials highlight a sampling of “Rupe’s PICKS” based on multiple observations in landscapes of the lower Midwest.

For Full Sun

a photo of Allium Millennium

Allium ‘Millennium’

Allium ‘Millennium’ (Ornamental Onion)— This hybrid from Allium guru Mark McDonough has been picture perfect at the Citygarden in downtown St. Louis.  It forms a compact, upright clump of glossy green, thick and strappy leaves which emit a slight smell of onion when crushed.  In mid summer, a profusion of large 2”, bright rosy purple, tightly rounded clusters of flowers appear on strong stems just above the attractive foliage.  Butterflies and honeybees adore their sweet nectar but deer and rabbits steer clear of this perennial beauty.  This selection has not been known to reseed in the landscape and is very easy to grow.

A photo of Aster KICKIN' SERIES Lavender

Aster KICKIN’ SERIES Lavender

Aster KICKIN SERIES (Aster)— Out with the old perennial technology and in with much improved aster genetics! The KICKIN SERIES offer naturally compact asters with a superb habit, forming a bushy, 24” – 30” mound of foliage.  Just in time for late summer-early autumn color, every inch of foliage is covered in flowers.  Enjoy such selection as KICKIN `Lavender’, KICKIN `Lilac Blue’, and KICKIN `Pink Chiffon’.  Beginning In 2015, get ready for KICKIN `Carmine Red’!

A photo of Echinacea 'Pica Bella' Coneflower

Echinacea ‘Pica Bella’ Coneflower, photo courtesy Stone House Nursery

Echinacea ‘Pica Bella’ (Coneflower)— Really, another purple coneflower variety?  Yes! Pica Bella is a durable, compact (24”) coneflower sets this selection apart from the rest with  deep pink petals held horizontally around the orange bronze cone. Dark green foliage and sturdy flower stems complement this highly floriferous selection of our native coneflower.

 A photo of Heliopsis helianthoides 'Tuscan Sun'

Heliopsis helianthoides ‘Tuscan Sun’

Heliopsis helianthoides ‘Tuscan Sun’ PP18763 (False Sunflower)—This beautiful and carefree native cultivar from Proven Winners® offers a more compact habit (24-30” height) than the native species and good disease resistance compared to other varieties of Heliopsis.  Bright golden yellow, daisy-like flowers with an orange-gold button center are produced on strong stems from mid through late summer atop the deep green foliage.  It provides a brilliant beacon of color in the landscape during the hottest months of summer.  Blooms after the Black-Eyed Susan’s have graced the landscape with golden color.

A photo of Hibiscus 'Midnight Marvel'

Hibiscus ‘Midnight Marvel’

Hibiscus ‘Midnight Marvel’ PPAF (Rose Mallow)— This outstanding selection combines some of the best genetics among popular hardy hibiscus varieties, including very deep wine purple, dissected maple-like foliage that is thick and leathery.  Like many perennials with purple foliage, this hibiscus requires direct exposure to UV light (grown in full sun) to achieve the darkest foliage color.  The flowers begin as glossy, black-red buds and open to 8-9”, deep scarlet red petals.  The habit is relatively compact, measuring in at 4’ tall x 4 ½’ wide which is intermediate in size between its parents.  Since this variety is an indeterminate bloomer (has buds at several nodes up the stem), it blooms for an extended period from midsummer into early fall.

A photo of Nepeta faassenii 'Purrsian Blue'

Nepeta faassenii ‘Purrsian Blue’

Nepeta faassenii ‘Purrsian Blue’ PPAF (Catmint)—Among the many catmints, this new selection offers a significantly improved tidy habit, being a bit smaller and more compact in size (14-18” height).  In its first year, ‘Purrsian Blue’ forms a small, perfectly rounded, densely branched clump of tiny, green leaves.  In year two, the plant maintains its compact mounding habit but nearly doubles its spread to just over two feet across.  This is a very floriferous selection whose flower power is amplified by its having its flowers spaced closely together on the stems.  Periwinkle blue flowers are coddled by dark purple calyxes just above the aromatic foliage from early summer into early fall.  ‘Purrsian Blue’ has everything today’s gardeners are looking for: a low maintenance, drought tolerant, deer resistant, long blooming perennial that looks great all season.

A photo of Perovskia atriplicifolia 'PEEK-A-BLUE'

Perovskia atriplicifolia ‘PEEK-A-BLUE’

Perovskia atriplicifolia ‘Peek-a-Blue’ PPAF (Russian Sage)—While Perovskia ‘Little Spire’ is prized for its compact habit, it grows a bit tall for some who are looking for a shorter selection that works well in smaller urban gardens.  After many years of breeding efforts, Perovskia ‘Peek-a-Blue’, is introduced as a short selection of P. atriplicifolia with a compact habit and attractive, finely dissected foliage.  Very lacy, silvery green leaves line the silvery stems topped with lavender blue flowers from midsummer into early fall.  The plants measure just over 2’ tall when they are in full bloom.  In the landscape, they peek out between shorter plants in the front of the border and taller plants in the back.  Very drought tolerant and extremely deer and rabbit resistant!

A photo of Rudbeckia fulgida var. sullivantii 'Little Goldstar'

Rudbeckia fulgida var. sullivantii ‘Little Goldstar’

Rudbeckia fulgida var. sullivantii ‘Little Goldstar’ PP22397 (Black-Eyed Susan)— The deserving new standard in Rudbeckia! A much more compact, proportional selection graced with a dome of star-shaped, 2-21/2”, golden yellow blossoms carried on very well-branched scapes rising above rich green foliage.  Extremely resistant to septoria black leaf spot, a fungus commonly found on the highly antiquated `Goldsturm’ selection.

A photo of Stachys monieri 'Hummelo' (Betony)

Stachys monieri ‘Hummelo’ (Betony)

Stachys monieri ‘Hummelo’ (Betony)— Although not a “new” perennial on the scene, the flowering Stachys deserve greater use in the landscape.  Distinctively different than its cousin, Lamb’s Ear, `Hummelo’ forms large compact clumps of rich green, textured leaves.  Early summer showy spikes of densely packed, rose purple flowers shoot up through the foliage on 18-20” stalks.  This unique flower form does not compete but rather complements so many other perennials.  Extremely rabbit and deer resistant.

For Shade

A photo of Geranium microrrhizzum 'Bevan's Variety'

Geranium microrrhizzum ‘Bevan’s Variety’, photo by Robert Weaver

Geranium macrorrhizum ‘Bevan’s Variety’ (Cranesbill)— Another champion for the deer and rabbit impacted shade landscape.  A wonderful colonizing groundcover geranium with aromatic foliage sporting thick clusters of deep magenta flowers blooming mid-spring into early summer.  This 8-12” dependable shade perennial is extremely rabbit and deer resistant.

A photo of Hakonechloa macra 'All Gold'

Hakonechloa macra ‘All Gold’

Hakonechloa macra ‘All Gold’ (Hakone Grass)— An extremely colorful and graceful ornamental grass with brilliant solid gold foliage for brightening the shade garden.  Compared to its sister, `Aureola’, the cultivar `All Gold’ exhibits much improved vigor, colonizing slowly to form a clump ground cover.  The foliage, with a mature height of 9-14”, turns a variety of autumn color after the first frost.  Another highly deer and rabbit resistant perennial for shade!

A photo of Helleborus 'Ivory Prince'

Helleborus ‘Ivory Prince’

Hellebores (too many superior cultivars to list just one!) (Lenten Rose)— Wow, for the deer and rabbit impacted landscape, Hellebores are a must for the shade garden.  Requiring minimal water application during drought weather conditions, the numerous selections of Hellebores are the perfect choice for placement under mature shade tree species sensitive to excessive supplemental irrigation.  The semi-evergreen nature of the foliage provides a bonus throughout the dormant months of winter.  A diversity of cultivars offer a plethora of flower colors  and forms in association with a variety of foliage characteristics.  A few favorite Lenten Rose selections include `Ivory Prince’, `Pink Frost’, `Winter Sunshine’, `Sunshine Ruffles’ and `Peppermint Ruffles’.

 Bill Ruppert is owner and manager of the St. Louis office of National Nursery Products, Inc.,  a horticultural sales, marketing and consulting company representing regional and national wholesale growers of ornamental and environmental landscape plants.