Perennially Reliable Performers
Joe Gadbois, June 9, 2025
Did you know that June is Perennial Gardening Month? This has been promoted by the Perennial Plant Association for years, because, after the mad spring planting rush of May, June is an excellent time to visit your local garden centre and peruse the perennial section. Perennials available for sale are typically more mature, and at Greenland you will find plenty of colour as summer perennials begin to bloom. In the absence of crowds of people frantically trying to fill their carts with plants, you can take a more relaxed, methodical approach to selecting plants for your garden, and our staff are happy to help you make informed decisions.
In the spirit of Perennial Gardening Month, I wanted to share with you some of the perennials I find easy to recommend because they are reliable, strong performers.
Daylily (Hemerocallis spp.)
Not a true lily, the daylily is one of the all-around best perennials for Alberta. It forms a well-behaved clump of attractive grassy foliage (the old-fashioned, weedy orange daylily, Hemerocallis fulva, is no longer available in the trade). In summer, tall scapes bearing clusters of lily-like flowers appear. Depending on the variety, plants may reach anywhere from about 14 inches to 4 feet in height, and about 18-30 inches wide. The blooms come in a variety of colours and can be fragrant. The name “daylily” alludes to the fact that each flower only lasts a day, but they open in succession so you will have blooms for several weeks. Many varieties are reblooming and will put on an extended show over most of the summer.
Daylilies prefer full sun to part shade and are not picky about soil as long as it is not waterlogged. Plants do not need regular division, but old clumps will eventually need dividing in fall if they stop blooming well.
Recommended varieties in stock now: Aramis, Bakabana, Bela Lugosi, Calico Jack, Chicago Apache, Golden Zebra, Hanalei Bay, Marque Moon, Moses Fire, Night Beacon, Pardon Me, Perceptive, Simmons Overture, Water Dragon.
Hosta (Hosta spp.)
One of the easiest plants to recommend for shade, in fact no shade garden is complete without at least one! This is one of the most reliable perennials out there. Grown for its foliage, there are countless choices available, with a few broad categories: green, chartreuse, blue, and variegated; variegated varieties can have a green, chartreuse, or blue base colour and can have numerous different patterns. Plants range from miniatures that are only a few inches tall and wide, to gargantuan specimens 4 feet tall and 5 feet wide, with leaves that can individually be over a foot across! Most lie somewhere in-between these two extremes, and there is a choice for any size requirement. They are invaluable accents in the garden, providing contrast in both colour and texture.
Dainty lily-like flowers also appear in summer, and in most varieties are a pale mauve colour, but can also be white (or very rarely pale yellow). Some varieties have fragrant flowers. Hostas are long-lived and low maintenance, rarely needing division. They do best with rich, moist, well-drained soil. For best results, amend your soil with up to one-third Sea Soil or compost by volume at planting time, then add 1-2 inches of Sea Soil or compost to the soil around the plants each spring.
Green and chartreuse varieties, as well as those with variegated margins, are adaptable to sunny positions as well.
Recommended varieties in stock now: Autumn Frost, Coast to Coast, Drop-dead Gorgeous, Gold Standard, Liberty, Party Streamers, Patriot, Silly String, Wiggles & Squiggles, Wild Imagination, Wind Beneath My Wings, Wu-La-La
Siberian Iris (Iris sibirica)
I have always loved Irises for the rainbow of colours and kaleidoscope of patterns they come in. Siberian Irises are a very hardy type which have the benefit of grassy foliage that looks great even when the plants aren’t blooming. People often mistake them for ornamental grasses when they aren’t blooming; the upright clumps are tidy and well-behaved. When they do bloom in June, mature clumps provide a nice splash of colour, and today’s hybrids offer a greater variety of colours than ever before. Depending on variety, plants will reach about 2-3 feet tall and 18-24 inches wide at maturity.
Siberian Irises will grow almost anywhere: sun to part shade, and in most soil types, tolerating both drought (once established) and wet areas. Old clumps may start to die out in the centre, necessitating division in the fall.
Recommended varieties in stock now: Butter & Sugar, Caesar’s Brother, Cape Cod Boys, Jeweled Crown, Miss Apple, So Van Gogh, Uncorked
Peony (Paeonia spp.)
I am one of countless people who grew up around peonies – they were my grandma’s favourite flower. Her birthday also landed around the time they would start to bloom in our garden, so as a boy I would always pick her a bouquet of peonies for her birthday. In my opinion, they are hard to rival as a cut! Most people think of peonies as a double, fragrant, rose-like bloom that comes in pink, white, or red. What’s amazing about peonies is that in addition to these lovely choices there are numerous other forms and colours of bloom out there. For example, single-flowered varieties look like giant poppies and don’t usually need support because the blooms aren’t as heavy. Customers often overlook these when shopping for peonies but exclaim when they see them in full bloom in our display garden, and don’t even recognize them as peonies! There are also the exotic tree peonies, and Itoh peonies which combine the best traits of both tree peonies and standard herbaceous peonies.
The handsome bushy foliage of a peony is adorned with their large, incredibly showy flowers in early to midsummer. If you plant a range of different varieties, which bloom at slightly different times, you can extend the bloom season from late May to early/mid July. It’s important to understand that peonies are slow to establish, and it will take several years after planting for a peony to develop into a mature plant. Young peonies often have smaller flowers that don’t display their mature form. The clumps will gradually increase in size each year, but all above-ground growth for the season occurs in spring, so once flower buds are showing and leaves are fully unfurled, the plant will not grow any larger that season. Most varieties reach about 3 feet tall and wide when fully mature.
Plant in full sun for best results, but peonies will also grow well in part shade. The soil should be fertile, moist, and well-drained. Avoid planting too deeply or plants will not bloom; plant at the same level as plants were potted or so eyes are no more than 2 inches below the soil surface.
Recommended varieties in stock now: Bartzella, Bowl of Cream, Bridal Shower, Duchesse de Nemours, Festiva Maxima, First Arrival, Krinkled White, Paula Fay, Pietertje Vriend Wagenaar, Sarah Bernhardt, Sonoma Ye Do, Red Grace
Pinks (Dianthus spp.)
I rave a lot about pinks, which I prefer to call by their scientific name, Dianthus. If you’re looking for a perennial that will bloom all summer, this is one of the few that fits the bill. Older varieties will only sporadically rebloom after the main flush in late spring/early summer, but modern varieties bloom continuously the entire season. Related to carnations, border Dianthus can have single or double flowers in eye-popping colours ranging from shades of pink to red, purple, white, and even yellow. The blooms have a lovely clove-like scent and sit atop a mound or mat of semi-evergreen blue-green foliage that is attractive in its own right. Plants typically reach about 8-12 inches tall and 12-18 inches wide.
Dianthus must have well-drained soil and are drought tolerant once established. Never plant in heavy or waterlogged soil. They also need full sun. They’re ideal for rock gardens and edging sunny borders.
Recommended varieties in stock now: Kahori, Kahori Scarlet, Mad Magenta, Mountain Frost Series, Sunflor Series, Vivid Bright Light, Vivid Cherry Charm
Salvia (Salvia spp.)
Salvia is hands-down one of the best landscape perennials for reliability and performance. These form an upright, bushy clump of aromatic foliage, topped with spikes of showy blooms. They are among the longest blooming perennials and are rarely troubled with pest and disease problems. Traditionally available in shades of blue and purple, shades of pink and white are also available. Shear plants back after blooming for a second flush of blooms a few weeks later. The flowers will attract all sorts of pollinators.
Salvia is easy to grow and prefers fertile, moist, well-drained soil but will thrive in any well-drained soil and is drought tolerant once established. Full sun is ideal, but part shade works also. Depending on the variety, plants will reach 10-30 inches tall and 12-24 inches wide.
Recommended varieties in stock now: Big Sky, Blue by You, Blue Marvel, Caradonna, May Night, Rose Marvel, Spring King Mini