A well-designed garden offers interest from early spring to after autumn and beyond, if you also choose plants for the winter structure. But for the main growth period, much of this interest comes from flowering and deciduous plants. Gardeners who want a lower care landscape would be wise to look for perennials that are both easy to grow and offer a long flowering period. Most perennials bloom for two to four weeks, but longer perennials like coneflowers and catnip measure their flowering in months, not weeks.
The Longest Perennials
When planning a garden with long-flowering perennials, the same basic rules of design apply; choose a mixture of early, medium and after flowering plants. Of course, you can also set both the flowering period and the duration of the flowering period with pruning practices; pinching, dead head and shearing. Read on to find out how you can promote the flowering months by combining smart pruning with longer flowering perennials.
The First Bloomers:
Catmint ‘Walker Low’ (Nepeta racemosa ‘Walker Low’, Zones 3 to 9). With its habit of relaxed and trouble-free growth, the “Walker’s Low” catnip is ideal for a cottage garden or rock garden, or for the front edge of a perennial border or rose garden. In addition, plants bloom from after spring to mid-autumn with a heavy view of blue-purple flower grains, which are extremely attractive to pollinators and beneficial insects. No wonder this drought-resistant plant was voted perennial of the year 2007. As soon as the original color of the flowers begins to fade, give the plant a haircut and cut it By about half. Without cutting, the plant will continue to bloom moderately, but good shearing will promote neat foliage and many flowers that will persist until frost.
Geranium ‘Rozanne’ (geranium x ‘Rozanne’, zones 4 to 9). I don’t like to throw the term “low maintenance” at irresponsibility, but with “Rozanne” it’s the perfect description. This winter-hardy plant forms mounds 12 to 18 inches tall of spreading foliage that is crowned with two inches wide, blue-purple flowers from early summer to frost. After its first flowering, the plants will continue to pump a moderate amount of fresh flowers for months. However, if you shear the plants by a third after the first flowers disappear, you will encourage another flower show.
Heart blood ‘luxuriant’ (Dicentra formosa ‘luxuriant’, zones 2 to 9). Long-flowering perennials for shady spaces are difficult to find, but here shines “lush”! This rustic selection grows knee-deep and produces reddish-pink heart-shaped flowers in after spring and summer. Ferny foliage is also attractive and makes a beautiful leaf for old-fashioned flowers. Plant this shade-tolerant perennial in a wooded garden, on a shady edge or along a tree-lined path. Cutting withered flowers ensures months of flowering.
Ornamental onion ‘Millenium’ (Allium ‘Millenium’, Zones 5 to 9). The 2018 perennial plant of the Year, ‘Millenium’, is a striking selection with grassy leaves and round flowering shrubs two inches in diameter in a cheerful lavender-purple hue. The flowers bloom every summer for about six weeks, attracting every useful bee, butterfly and insect for miles. The one-foot tall and wide tufts are perfect for the front of a perennial border or stone garden where spherical flowers can be enjoyed. Technically a bulb, this plant is usually sold as a potted perennial and can be planted in spring or autumn. Unlike many perennials, pruning no longer produces flowers.
Echinacea ‘White Swan’ and ‘Magnus’ (Echinacea purpurea, Zones 3 to 9). Coneflowers are the cornerstone of a perennial summer garden that blooms for months even in dry, warm conditions, providing food for butterflies, bees and other pollinators. There are countless varieties for gardeners, but during months of flowering it is hard to beat Old-school selections like’ Magnus ‘and’White Swan’. ‘Magnus’ is a classic echinacea with purple flowers, while ‘White Swan’ has large flowers with white petals and orange-copper cones. Both bloom from the beginning of summer to the middle of autumn, especially if they have died regularly.
Coreopsis ‘Full Moon'(Coreopsis x ‘Full Moon’, Zones 5 to 9). This showy plant is one of the longest flowering perennials, with a season from early summer to early autumn. This is also the first launch of Coreopsis’s new “Big Bang” series, featuring large, soft yellow flowers that can grow up to three inches in diameter. It also has excellent drought tolerance and is popular pollinator. ‘Moonbeam’is another popular long-flowering Coreopsis, whose pale yellow flowers are smaller but no less lush than those of ‘Full Moon’. With both varieties, deadhead flowers fade to favor new buds.
Astilbe (Astilbe species, zones 4 to 9). Astilbe is one of the longest flowering perennials. In addition to being super easy to grow, they thrive in sunny and shady gardens and have feathered flowers that offer months of graceful color. And when talking about color, the flowers can be white, lavender, lilac, bubblegum, dark pink, apricot or red, often with bronze or purple foliage. Plants form tidy clumps with flower wings that appear from early to mid-summer and persist into winter. Plants appreciate moisture very much, and regular watering during dry summers can prolong the flowering period. The most notable varieties are ‘Bridal Veil’, ‘Pumila’and ‘ Fanal’.
Fantastic autumn flowers:
Black-eyed Susan ‘golden storm’ (Rudbeckia fulgida ‘golden storm’, Zones 3 to 9). Widely regarded as one of the best perennials of all time, ‘Goldstrum’ lights up the garden in after summer with weeks and weeks of bright colours lasting until October. Each echinacea-shaped flower has a raised chocolate-brown central cone surrounded by golden petals. Drought tolerant plants grow about two feet tall and provide the best visual effect when planted en masse. Deadhead faded flowers to prolong the flowering period.
Purple flame grass (Miscanthus sinensis ‘Purpurascens’, Zones 3 to 9). Young herbs give the perennial border a striking shape and texture throughout the summer. In after summer, many varieties produce soft, pinnate feathers that appear above the narrow foliage. Purple Flame Grass is a medium-sized grass that grows three to four meters high with foliage that turns from bright green to fiery red-orange in early autumn. The beautiful feathers are silvery white and remain on the plants all winter. Plant it in a sunny place with well-drained soil. Pruning is necessary only in early spring, when dried foliage and flower stems of the previous season are cut before the appearance of fresh growth.