Top Performing Perennials of 2018
December 16, 2018
Brought to you by Bob and Joe, Greenland’s resident “perennial geeks”, who are constantly trialling new and old varieties alike and gathering feedback from friends, customers, and staff. Here is a list of some of the perennials that performed admirably in central Alberta this year. Some new, some old, some “rediscovered”, any of these are sure to impress.
Check our website in March for a listing of perennials we expect to have available in 2019, and look out for these!
Wooly Rock Jasmine - Androsace lanuginosa
- Vigorous alpine groundcover
- Forms a low mat of silvery-grey, woolly foliage
- Bright pink, yellow-eyed flowers appear almost continuously from late spring to fall
- Great in rock gardens, alpine gardens, retaining walls or as a groundcover in hot and dry areas
- Requires excellent soil drainage
- 2-3” x 18-24”, full sun, zone 3
Dwarf Bergenia - Bergenia 'Flirt'
- A newer miniature variety of a classic garden perennial
- Forms a compact clump of glossy deep green, evergreen foliage
- Foliage turns deep plum-purple in fall and winter
- Produces a profusion of intense pink flowers in spring
- Fantastic in rock gardens, dry shady areas or as a border edger
- Easily grown in any average garden soil
- 6-8” x 8-10”, shade or sun, zone 3
Alpine Bellflower - Campanula chamissonis
- Beautiful alpine groundcover version of a garden classic
- Plants gradually spread to form a mat of deep green, glossy leaves held almost at ground level
- Up-facing, bell-shaped, bright blue flowers with white interiors appear in spring and early summer
- A great addition to rock gardens, alpine gardens, retaining walls, or as a groundcover in areas with fertile, moist but well-drained soil
- Hardy and easy to grow
- 2-3” x 12-18”, sun to pt. shade, zone 3
Clematis 'Joe Zary' - Bigpetal Clematis
- One of the hardiest Clematis for the Prairies
- Vigorously growing plants produce masses of down-facing, violet-blue flowers with white centres almost continuously from late spring to late summer
- An easily grown vine preferring fertile, moist, well-drained soil
- Prune lightly each spring, thinning out the oldest wood; flowers are produced from old and new wood
- 8-10’ x 3-4’, sun to pt. shade, zone 3
Lady's Slipper - Cypripedium 'Memoriam Shawna Austin
- Stunning hardy orchid hybrid for the outdoor garden
- Plants gradually multiply to form clumps, topped with gorgeous slipper-shaped flowers in spring
- Blooms have a copper-orange background, heavily overlaid and suffused with deep plum-red
- Ideal for the shady border or woodland garden
- Requires loose, moist, slightly acidic, well-drained soil
- 12-18” x 12”, pt. shade, zone 3
Garden Pink - Dianthus plumarius 'Pikes Pink'
- One of the hardiest and best-performing pink varieties on the Prairies
- Forms a tidy clump of needle-like, frosty blue-grey foliage
- Double, clove-scented, light pink flowers appear continuously from late spring through most of the summer
- A great plant for rock gardens, border edging, and hot and dry areas
- Requires excellent soil drainage
- 8-12” x 12”, full sun, zone 3
Goldleaf Bleeding Heart - Dicentra spectabilis 'White Gold'
- This new white-flowered form of the popular ‘Gold Heart’ variety is surprisingly luminescent in the garden
- Strands of heart-shaped, pure white flowers against the bright golden leaves and stems absolutely glisten in the morning sunlight and really brighten up a shady area
- Forms a large, bushy clump
- Prefers moist, well-drained soil
- 2-3’ x 3’, pt. shade to shade, zone 3
Stemless Gentian - Gentiana acaulis 'Undulatifolia'
- Superb alpine perennial
- Forms a low mat of glossy evergreen leaves
- Large, up-facing, trumpet-shaped, royal-blue flowers with green throats appear in spring to early summer, often reappearing in fall
- A prime candidate for rock gardens, alpine gardens, or as a groundcover in areas with fertile, moist, well-drained soil
- Excellent soil drainage is essential
- Avoid sun-baked areas with dry soil
- Also try Gentiana verna (spring gentian), a tiny alpine species with electric blue flowers with white centres that appear in early spring
- 3-4” x 12-18”, sun to pt. shade, zone 3
False Sunflower - Heliopsis helianthoides var. scabra 'Burning Hearts'
- A fabulous newer variety that is performing extremely well for us
- Upright clumps of disease-resistant, purple-tinged foliage on sturdy stems
- Daisy-like, eye-popping yellow flowers with orange-red centres bloom from midsummer to fall – very long-blooming
- Easily grown in any average garden soil
- Also try Heliopsis helianthoides ‘Sunstruck’ – a dwarf variety with stunning cream-variegated foliage
- 4’ x 16 inches, full sun, zone 3
Coralbells - Heuchera 'Forever Red'
- A new variety with incredibly rich, fiery red foliage that retains its colour all year in locations that receive at least a few hours of direct sunlight
- Sprays of deep pink flowers last all summer
- Prefers fertile, moist, well-drained soil
- Foliage is evergreen, so do not cut back in fall, but lift clumps every 3-4 years and replant at the proper depth, as they like to climb out of the soil
- Mulch for winter if good snow cover is not guaranteed
- 12-18” (with flowers) x 12-16”, pt. shade to sun, zone 4
Coralbells - Heuchera Northern Exposure Series
- New breakthrough breeding utilizing northern species has resulted in hybrid coralbells that are hardier, better performers on the Prairies, without sacrificing the amazing colours that can be had in the “fancier” varieties
- Try ‘Amber’, ‘Black’, ‘Lime’, ‘Purple’, ‘Red’, and ‘Silver’
- Plants quickly form thick crowns for overwintering performance
- Prefers fertile, moist, well-drained soil
- Foliage is evergreen, so do not cut back in fall, but lift clumps every 3-4 years and replant at the proper depth, as they like to climb out of the soil
- 12-18” (with flowers) x 12-16”, pt. shade to sun, zone 3
Hosta 'Curly Fries'
- Relatively new variety of small-sized Hosta
- Produces a compact clump of narrow, wavy-edged leaves in a chartreuse-yellow colour that will be brighter with more sun exposure
- A profusion of lilac-purple, lily-like flowers on tall stems lasts most of the summer
- Excellent in rock gardens, woodland gardens or the front or edge of a border
- Easily grown in any average garden soil
- 12-18” (with flowers) x 10-14”, shade to sun, zone 3
Bitterroot - Lewisia 'Constant Comment'
- A dwarf, reblooming variety of this beautiful arid plant
- Produces a low clump of narrow, deep green, succulent leaves
- Masses of intense pink flowers on short stems appear almost continuously throughout the summer and into fall
- Perfect in rock gardens, alpine gardens and xeriscaping
- Requires sharply-drained soil; plant crowns on sand or grit to avoid rot
- 4-6” x 6-8”, full sun, zone 3
OT Lily - Lilium 'Touchstone'
- OT lilies, also called orienpet or “tree” lilies, are the result of crossing Oriental lilies with trumpet lilies
- These hybrids have the very large and scented flowers of Oriental lilies, but are hardier and more vigorous growers
- ‘Touchstone’ has enormous, deep reddish-magenta flowers with yellow-green throats, appearing in midsummer
- Stems are tall and strong, clothed with attractive foliage; excellent for cutting
- Bet in rich, moist, well-drained soil
- Mulch for winter where good snow cover is not guaranteed
- 4-6’ x 12-18”, full sun, zone 3
Lupine - Lupinus Westcountry Series
- This newer line of lupines developed by Westcountry Nurseries in the UK has produced some of the finest lupines ever seen, with incredibly large and full flower spikes in very bold colours
- Some of our favourites we have tried so far are ‘Blacksmith’ (bicolour blue/white), ‘Gladiator’ (bicolour pink/yellow), ‘Manhattan Lights’ (bicolour purple/yellow), ‘Masterpiece’ (solid purple), ‘Persian Slipper’ (solid blue), and ‘Red Rum’ (solid red)
- We are still trying to determine whether these plants are monocarpic (die after blooming), as some lupines are, or whether they are not fully hardy in central Alberta. We have found that mature plants self-seed and the seeds do germinate the following spring, but the parent plants do not return
- Lupines grow best in well-drained soil that is not too rich
- 20-30” x 12-18”, full sun, zone 4 (tentative)
Campion - Lychnis x arkwrightii 'Scarlet O'Hara
- A fabulous clump-forming perennial for the sunny border
- Produces mounds of purple-tinged foliage, topped with large, fringed, scarlet-red flowers in early summer
- Plants will rebloom if deadheaded, and can benefit from a shearing back in midsummer to maintain a compact and tidy growth habit
- A very similar variety, with bright orange flowers, is ‘Orange Gnome’
- Prefers moist, well-drained soil
- 10-16” x 12-18”, full sun, zone 3
Itoh Peony - Paeonia 'Bartzella'
- Despite the many newer varieties of Itoh peonies now available, this is still our favourite
- Itoh peonies are hybrids between herbaceous garden peonies and tree peonies; they inherit the large flower size, incredible colours and sturdiness of tree peonies, and the hardiness of herbaceous peonies
- Semi-double blooms can be nearly dinner plate size, bright yellow with red flares near the centre, and do not attract ants as herbaceous peony blooms do
- After several years, mature plants form a large and dense, bushy clump and can have as many as 100 flowers on a single plant, appearing over 3 weeks in the first half of summer
- Prefers fertile, moist, well-drained soil
- Another excellent variety to try is ‘Duchesse de Lorraine’, which is essentially the fully double form of ‘Bartzella’
- 3-4’ x 3-4’, full sun, zone 3
Alpine Beardtoungue - Penstemon rupicolo 'Pink Holly'
- A woody alpine groundcover perennial
- Forms a low mat of woody stems clothed in evergreen leaves
- Masses of large, tubular, bright pink flowers appear in late spring to early summer and will attract butterflies and hummingbirds
- A superb addition to rock gardens, alpine gardens, retaining walls, or as a groundcover in sunny areas with well-drained soil
- Excellent soil drainage is required
- 4-6” x 12-18”, sun to pt. shade, zone 3
Hybrid Moss Phlox - Phlox Chicagoland Series
- This newer line of hybrids incorporating several alpine Phlox species has demonstrated superior qualities compared to older moss phlox and arctic phlox varieties
- Plants will develop a mat or spreading cushion of lush semi-evergreen, needle-like foliage, completely smothered with fragrant, colourful flowers from late spring, well into summer
- Blooms attract butterflies
- A few of our favourites are ‘Violet Pinwheels’ (purple), ‘Running with Scissors’ (lavender with darker centre), and ‘Plumtastic’ (purple fading to lilac)
- Plants are very resistant to downy mildew
- Fantastic in rock gardens, alpine gardens, retaining walls, or as groundcover in sunny areas
- Excellent soil drainage is required
- 2-4” x 12-18”, full sun, zone 3
Auricula Primrose - Primula auricula Bavarian Gaudi Series
- A fantastic line of primula developed in Europe
- Plants develop a low, compact clump of rosetted, semi-evergreen, succulent foliage
- Clusters of gorgeous, fragrant flowers appear on short stems in spring and are so perfect, they almost look artificial
- Some of our favourite varieties from the series are ‘Mariandl’ (deep purple/white with lighter purple edge), ‘Basti’ (red/yellow), ‘Hanni’ (burgundy/yellow), and ‘Berti’ (pink/white)
- Ideal for rock gardens, alpine gardens, or at the front or edge of a semi-shaded border
- Require fertile, moist, well-drained soil; not for either hot and dry areas or wet areas with poor drainage
- 6-8” x 6-8”, pt. shade to sun, zone 3
Salvia or Blue Sage - Salvia nemorosa 'Blue Marvel' and 'Rose Marvel'
- Newer varieties of a garden classic
- Both versions are remarkable for having a more compact growth habit and more colourful, more densely-packed flower spikes compared to older varieties
- ‘Blue Marvel’ has deep blue flowers, while ‘Rose Marvel’ has deep pink flowers
- The blooms appear most of the summer (deadheading encourages more rebloom) and will attract butterflies and hummingbirds
- Foliage is aromatic
- Prefers moist, well-drained soil
- 12” x 12”, full sun, zone 3
Little Bluestem - Schizachyrium 'Smoke Signal'
- A stunning newer variety of perennial ornamental grass
- Plants develop upright clumps of blue-green blades, gradually changing to a deep smoky-purple colour by fall
- An ideal low-maintenance option, excellent for hot and dry areas, that will provide interest year-round
- Requires well-drained soil that is not too rich
- 3-4’ x 18-24”, full sun, zone 3
Stonecrop - Sedum Sunsparklet Series
- We are still raving about this superior line of compact, mound-forming sedums
- The tidy mounds of succulent foliage are available in several eye-popping colours
- Excellent in rock gardens and xeriscape
- Some of our favourites are ‘Lime Zinger’, ‘Lime Twister’, ‘Firecracker’, ‘Dazzleberry’, ‘Plum Dazzled’, ‘Blue Elf’, ‘Blue Pearl’, and ‘Wildfire’
- The foliage will be complimented by dazzling flowers from midsummer to fall, which are bee magnets
- Require excellent soil drainage; very drought tolerant
- For an excellent upright sedum, try ‘Elsie’s Gold’, which has gorgeous golden-variegated foliage
- 6-12” x 12”, full sun, zone 3
Hen & Chicks - Sempervivum Chick Charms Series
- This newer series of hens & chicks varieties has taken this incredibly attractive and easy-growing perennial to the next level
- Plants form low, clumping rosettes of succulent leaves, which come in a range of intense colours that will really set off the area they’re in
- The colour is most intense in fall, winter, and spring, when temperatures are cooler
- Some of our favourites to check out from this series are ‘Appletini’, ‘Berry Blues’, ‘Bing Cherry’, ‘Chocolate Kiss’, ‘Cranberry Cocktail’, ‘Gold Nugget’, and ‘Plum Parfait’
- These are excellent for rock gardens, alpine gardens, border edging, and xeriscaping, and even make great container plants, as they are one of the few perennials that will reliably overwinter in containers in central Alberta!
- Try combining several different varieties with decorative rocks to create a beautiful and low-maintenance outdoor succulent dish garden
- Requires excellent soil drainage
- 2-3” (without flowers) x 6-12”, full sun, zone 2