June is Perennial Gardening Month. Celebrate by adding some new perennials to the landscape. The Perennial Plant Association helps gardeners make good choices. They have selected the best of the best and presented them in their Perennial Plant of the Year program.
The mission of the Perennial Plant Association is to educate everyone from industry professionals to home gardeners about perennials. It began its Perennial Plant of the Year™ program in 1990 to highlight outstanding perennials that are easy to grow in many areas of the country. Plants receiving the Perennial Plant of the Year™ award must also have more than one season of interest and demonstrate resistance to pests and diseases.
This year’s award winner, Asclepias tuberosa or butterfly weed, is a timely selection. Protecting monarch butterflies is a hot topic in gardening circles and the foliage of butterfly weed is a food source for monarch caterpillars. An ideal choice for hot and dry sunny gardens, patience is required in spring because it emerges late. Asclepias tuberosa grows up to 3 feet tall and not quite as wide. Its vibrant orange, flat-topped flowers brighten the landscape from midsummer to early fall.
In 2016, Anemone x hybrid ‘Honorine Jobert’ received the honor. Commonly called windflower, it grows up to 4 feet tall and half as wide, providing color to the garden when it is needed most in August and September. Tall slender stems present pure white flowers accented with yellow stamens. Plant Honorine Jobert windflower in compost-amended, well-drained soil in part shade to part sun. It cannot survive in soggy sites. Although it is a little slow to settle in, it spreads by rhizomes to form lovely colonies once established.
Geranium x cantabrigiense ‘Biokovo’ was named Perennial Plant of the Year in 2015. Small, pale pink flowers top a carpet of fragrant foliage from late spring to early summer. Plant this cutie at the front of border or use it as a ground cover in full sun to light shade.
Introduced by Roy Diblik of Northwind Perennial Farm, Panicum virgatum ‘Northwind’ took home the prize in 2014. If your garden needs a vertical element, Northwind switchgrass is a flawless selection. Blue green leaf blades stand as straight as a 4- to 5-foot soldier, forming a clump a couple feet wide. Fine-textured, pink-tinted flowers top the foliage in late summer. Panicum virgatum ‘Northwind’ is tolerant of many different soil types, but prefers lean, moist soil in a spot with full sun. Planted in a site too shady or with soil too rich, it may flop.
The Perennial Plant of the Year in 2013 was Polygonatum odoratum ‘Variegatum’. Commonly called Solomon’s seal, arching stems of white margined green leaves grow about 2 feet tall. White bell-shaped flowers in spring are followed by very dark blue berries in fall. Solomon’s seal spreads by rhizomes to form delightful colonies in part to full shade. While it prefers well-drained soil rich with organic matter, it thrives in the dry shade created by thirsty tree roots in my landscape.
Brunnera macrophylla ‘Jack Frost’ was named the Perennial Plant of the Year in 2012. This is a must have for gardeners struggling to grow perennials in dry shade. Clumps of large, heart-shaped, frosty white and dark green-veined foliage grows up to 18 inches high and wide and spreads slowly by rhizomes. It is commonly called false forget-me-not because of its sprays of bright blue forget-me-not-like flowers that bloom for six weeks in spring.
In 2011, Amsonia hubrichtii received the honor. A plant for three seasons, Amsonia hubrichtii boasts clusters of steel blue star-shaped flowers atop 3-foot stems of needle-like, bright green foliage in late spring to early summer; feathery fine texture to compliment other perennials all season; and brilliant golden yellow fall color. Commonly called blue star, it is not fussy about where it’s planted – sun or light shade, moist to dry soils. The best floral show occurs when it’s planted with some afternoon shade; the best fall color occurs when it’s planted in full sun.
And the winner of the Perennial Plant of the Year in 2010 was Baptisia australis. Choose the site carefully for blue false indigo, as it is commonly called. Once it puts down its deep roots, it resents being moved. It is easy to grow in just about any soil, except soggy, in full sun to light shade. Looking more like a shrub than a perennial, it grows up to 4 feet tall and wide and shows off spikes of indigo blue flowers from late spring to early summer followed by large near-black seed pods in late summer and fall.
Hakonechloa macra ‘Aureola’ was named Perennial Plant of the Year of 2009. Elegant, arching, green leaves striped with gold add color to shade gardens. Plant Japanese forest grass in consistently moist, but well-drained soil amended with organic matter for best performance. Hakonechloa macra ‘Aureola’ is gorgeous tickling the edges of a shaded path or cascading over the edges of a container.
In 2008, Geranium ‘Rozanne’ was named the prize winner. This perennial geranium is a non-stop blooming machine. In all but the hottest of summers, it boasts violet-blue flowers from late spring until fall. Plants with lightly marbled, deep green foliage grow up to 20 inches tall and at least 2 feet wide. Grow Geranium ‘Rozanne’ in average, well-drained soil in full sun to part shade and let it weave its way through neighboring perennials.
The winner of the Perennial Plant of the Year award in 2007 was Nepeta ‘Walker’s Low’. This catmint grows about 2 feet tall and not quite as wide and favors well-drained soil in full sun to part shade. It tolerates drought but cannot survive in soggy soil. Lavender-blue flowers bloom in abundance over gray-green, fragrant foliage in spring. If flowers are cut back after blooming, another round of flowers follows in summer.
Dianthus gratianoplitanus ‘Firewitch’ received the honor in 2006. This little cutie shows off bright magenta flowers from mid-spring to early summer. Diminutive mounds of silvery-blue, evergreen, needle-like foliage with a clove-like fragrance grow up to 6 inches tall and slightly wider. As long as it is very well-drained, especially in winter, Firewitch cheddar pinks are not fussy about soil but require a site basking in sunlight.
In 2005, shade gardeners celebrated when Helleborus x hybridus took home the coveted prize. Given well-drained soil rich with organic matter, hellebores are a shade gardener’s best friend. Nodding flowers in shades of yellow, chartreuse, white, pink, burgundy and near black bloom in very early spring when little else has awakened from their winter nap. Hellebores prefer part shade but perform in full shade, too. Shiny, leathery, evergreen foliage grows up to 18 inches tall and wide.
Athyrium niponicum ‘Pictum’ won the Perennial Plant of the Year award in 2004. Japanese painted ferns contribute color and texture to the shade garden. Eighteen-inch, arching fronds are gray-green frosted with silver and highlighted with burgundy stems and veining. Spreading by rhizomes, Japanese painted ferns form dense colonies if planted in moist, but well-drained soil that has been generally amended with organic matter.
The Perennial Plant of the Year in 2003 was Leucanthemum ‘Becky’. Three- to four-foot sturdy stems present large, yellow-centered, white, daisy-like flowers all summer long over fresh green foliage. Deadheading flowers will help plants realize their blooming potential. Other than demanding well-drained soil, Becky is easy to grow in full sun.
Phlox ‘David’ won the award in 2002. The most mildew-resistant white-flowering phlox, this garden phlox grows 3 to 4 feet tall and 2 to 3 feet wide. Planted where it will receive good air circulation in moist but well-drained soil, Phlox ‘David’ blooms from mid to late summer in full sun to light shade. Best flowering occurs in full sun. Be sure to water garden phlox if there is not sufficient rainfall to keep the soil slightly moist.
In 2001, Calamagrostis x acutiflora ‘Karl Foerster’ was named Perennial Plant of the Year. Commonly called feather reed grass, clumps of bright green foliage grow up to 3 feet tall and 2 feet wide. Feathery, 5-foot plumes the color of sand rise above the foliage in early summer. Karl Foerster feather reed grass grows best in average to wet soils in a site with full sun. While they thrive in moist soil, they tolerate drier conditions, too.
In 2000, Scabiosa columbaria ‘Butterfly Blue’ received the coveted prize. Pincushion flower, as it is commonly called, grows up to 15 inches tall and wide and blooms and blooms and blooms, if deadheaded, from late spring until frost convinces it to stop. Multitudes of frilly, lavender-blue flowers top stiff, wiry stems above gray-green foliage. All Scabiosa columbaria ‘Butterfly Blue’ asks in return for an endless supply of flowers is a site in full sun with well-drained soil, especially in winter.
Rudbeckia fulgida var. sullivantii ‘Goldsturm’ received the award in 1999. The botanical name is a mouthful for the perennial commonly known as black-eyed Susan. A mainstay in summer landscapes, they flaunt bright, golden yellow, daisy-like flowers with dark brown centers beginning in June and continuing to September. Clumps of dark green foliage spread slowly by rhizomes, reaching up to 3 feet tall and 2 feet wide in average, well-drained soil in full sun to light shade.
Echinacea purpurea ‘Magnus’ was named Perennial Plant of the Year in 1998. Just like the black-eyed Susan, purple coneflowers are traditional favorites in summer gardens. Easy to grow in average, well-drained soil in full sun to light shade, butterflies love them as much as gardeners. Magnus purple coneflowers grow up to 3 feet tall but just 18 inches wide, displaying rose-purple petals – held more horizontally than other varieties – surrounding large, deep orange cones. Goldfinches snack on seeds if spent flowers are left standing for winter.
In 1997, Salvia ‘May Night’ was the award recipient. Eye-catching spikes of tiny, tubular, deep purple-blue flowers on stems reaching up to 24 inches tall bloom from late spring to early summer. Cut back flowering stems after flowers have faded and another flush of blooms will follow in a few weeks. Planted in full sun in average, well-drained soil, Salvia ‘May Night’ glows when partnered with silver-foliaged neighbors.
The Perennial Plant of the Year in 1996 was Penstemon digitalis ‘Husker Red’. Ruby red basal foliage adds color to sunny perennial borders all season long. In late spring to early summer, stems rise up to 3 feet tall presenting so many pink-blushed white, tubular flowers they sometimes need staking. The only demand Penstemon digitalis ‘Husker Red’ makes is to be planted in well-drained soil. Soggy soil will cause its death. Bees, butterflies and hummingbirds visit flowers in summer. If left standing, songbirds nibble on seed heads in fall and winter.
In 1995, Perovskia atriplicifolia was the award winner. Commonly called Russian sage, it is lovely in classic summer combos with pink coneflowers or golden yellow back-eyed Susan. It grows 4 feet tall and almost as wide in average, very well-drained soils. Long stems of fragrant, silvery, gray-green foliage bear small and sweet, lavender-blue flowers beginning in mid-summer and continuing into fall. Perovskia atriplicifolia grows satisfactorily in part shade, but best flowering occurs in full sun. The stems of plants grown in too much shade will be lax.
Shade gardeners were delighted when Astilbe ‘Sprite’ was named the winner in 1994. As long as it has consistently moist, but well-drained soil amended with compost and a spot in part to full shade, this little beauty flowers like crazy in early summer. Water regularly and apply mulch around plants to help keep soil moist. Astilbe ‘Sprite’ produces masses of 12- to 18-inch feathery plumes of shell pink flowers over mounds of bronze-green, fern-like foliage. Consider Astilbe ‘Sprite’ when planting containers for the shade.
In 1993, Veronica ‘Sunny Border Blue’ was chosen as Perennial Plant of the Year. Speedwell, as it is commonly called, is an ideal choice for the front of a sunny border. As long as the soil is very well-drained, especially in winter, Veronica ‘Sunny Border Blue’ is very easy to grow given a spot with full sun. Eighteen to twenty-four inch spikes of dark violet-blue flowers bloom from late May until October if they are deadheaded regularly. Glossy, crinkled, dark green foliage is attractive all season.
Coreopsis verticillata ‘Moonbeam’ claimed the title in 1992. Easy-going and easy to grow, Coreopsis verticillata ‘Moonbeam’ is a must have in a sunny border. Plants grow up to 2 feet tall and wide. Hundreds, maybe thousands, of soft yellow flowers bloom at the top of fine-textured, needle-like foliage all summer long. It is not fussy about the soil it is planted in but must have full sun. If deadheading is your garden therapy, this plant will provide more therapy than any gardener can possibly need. Instead of deadheading each flower stalk, wait until the plant has finished its first flush of blooms and then cut the whole plant back by half to enjoy another round of flowers in early fall.
Heuchera micrantha ‘Palace Purple’ was named the Perennial of the Year in 1991. Commonly referred to as coral bells, gardeners loved this one with purple foliage so much hybridizers started creating new varieties and haven’t stopped yet. Palace Purple coral bells grows up to 2 feet tall and about half as wide in compost-amended, well-drained soil in light to part shade. It can handle some direct sunlight if it is cooler, gentler morning sun. Although it wouldn’t be grown for the flowers, it does offer tiny creamy white flowers on wiry, dark red stems in early summer. Add a layer of mulch around plants after the soil has frozen in winter to prevent frost heaving.
In 1990, Phlox stolonifera was the very first perennial to be named a Perennial of the Year. Commonly called creeping phlox, it has brightened spring landscapes for gardeners for many years. It forms a dense carpet of lavender less than a foot tall, spreading by stems on or just below the ground in full sun to part shade in moist, well-drained soil rich with organic matter.