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 landscape with less maintenance should look for perennials that are both easy to grow and offer a long flowering period. Most perennials bloom two to four weeks, but the longest perennials, such as cones and catnip, measure their flowering period in months, not weeks.
The Most Perennial
When planning a garden with long-flowering perennials, the same design rules apply; choose a mixture of early, mid-season and after flowering plants. Of course, they can also affect the flowering period and the length of the flowering period with pruning practices; pinching, Deadheading and shearing. Read on to find out how you can encourage flowers for months by combining smart pruning with the longest flowering perennials.
Catnip ‘Walker’ s Low ‘(Nepeta racemosa ‘Walker’ s Low’, Zones 3 to 9). With its relaxed and hassle-free growing habit, the “Walker’s Low” Catmint fits perfectly in a Cottage or rock garden or on the leading edge of a perennial border or rose garden. In addition, plants bloom from after spring to mid-autumn with a strong show of blue-purple flower spikes, which are extremely attractive to pollinators and beneficial insects. No wonder this drought-resistant plant was voted perennial of the year in 2007. As soon as the initial rinse of the flowers begins to fade, give the plant a haircut and cut it by about half. Without pruning, the plant continues to bloom moderately, but good pruning promotes neat foliage and many flowers that last 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 12-to 18-inch-high mounds from spreading foliage, which are crowned with two-inch-wide blue-violet flowers from early summer until frost. After the first flowering, the plants pump a moderate amount of fresh flowers for months. However, if you reduce the plants by a third after the first flowers fade, you encourage another strong floral exposure.
Bleeding heart ‘luxuriant’ (Dicentra formosa ‘luxuriant’, zones 2 to 9). Long-flowering perennials for shady rooms are difficult to get, but here shines “lush”! This rustic selection grows only to the knee and produces clusters of reddish-pink heart-shaped flowers in after spring and summer. The lazing foliage is also attractive and makes a beautiful leaf for old-fashioned flowers. Plant this shade-tolerant perennial in a wooded garden, shady edge, or along a tree-lined path. Cutting withered flowers ensures a flowering of several months.
Pruning tip-do not be afraid to grab this pruner as soon as the initial flowering of spring flowers begins to end. Many perennials, such as geranium ‘Rozanne’, will produce flowers throughout the Season, but in smaller quantities. If you want heavier flowering, shear plants one-third to one-half to bring out fresh foliage and flowers.
Ornamental onion ‘Millenium’ (Allium ‘Millenium’, Zones 5 to 9). The 2018 perennial plant of the Year, ‘Millenium’, is a striking selection with herbaceous foliage and rounded tufts of flowers two inches in diameter in a cheerful lavender-purple hue. The flowers bloom every summer for about six weeks and attract every bee, butterfly and useful insect for miles. The one-foot high and wide tufts are perfect for the front of a perennial border or stone garden where spherical flowers can be enjoyed. Technically, this plant is usually sold as a pot perennial and can be planted in spring or autumn. Unlike many perennials, pruning no longer produces flowers.
Sun hat to ‘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. Gardeners have countless varieties available, but for months of flowers it is difficult to surpass old-school choices like” Magnus “and”White Swan”. ‘Magnus’ is a classic lilac cone flower, while ‘White Swan’ has large flowers with white petals and copper-orange cones. Both bloom from the beginning of summer to the middle of autumn, especially if they are regularly dead.
Coreopsis ‘Full Moon'(Coreopsis x ‘Full Moon’, Zones 5 to 9). This remarkable plant is one of the longest flowering perennials, with a Season that stretches from early summer to early autumn. It’s also the first introduction to Coreopsis’s new “Big Bang” series, featuring large, soft yellow flowers that grow up to three inches wide. It also has excellent drought tolerance and is popular with pollinators. ‘Moonbeam’ is another popular long flowering Coreopsis with light yellow flowers, smaller but no less abundant than those of’Full Moon’. In both varieties, Deadhead blooms when they fade to favor new buds.
Astilbe (Astilbe species, zones 4 to 9). Astilbe stands out among the longest flowering perennials. Not only are they super easy to grow, but they also thrive in sunny and shady gardens and have feathered flowers that offer months of graceful color. Speaking of color, the flowers can be white, lavender, lilac, Bubblegum, dark pink, apricot or red, often with bronze or purple foliage. The plants form neat clumps with flower flags that appear in early to mid-summer and persist until winter. Plants enjoy abundant moisture, and regular watering in dry summers can prolong the flowering period. The most notable varieties are ‘Bridal Veil’, ‘Pumila’and ‘ Fanal’.
Achillea (Achillea millefolium, Zones 3 to 9). Yarrow is a favorite butterfly and a robust summer bloom with pretty flat flowers that bloom for 6-8 weeks. Mealy foliage appears in early spring and is followed in early summer by flower stalks two to four feet tall. Yarrow is one of the longest flowering perennials, which grows best in full sun with well-drained soil of medium fertility; over-fertilization can tip the stems. Floral colors can range from soft pastel tones to rich jewel tones. Deadhead passed flowers by cutting the flower stem back to the main foliage. Among the best varieties are ” Moonshine “with pale yellow flowers and” Cherry Queen”, a bright cherry-red bee magnet.
Pruning tip-as summer flowers wither, often deadhead, cut on a fresh stem or a set of leaves. This will encourage plants to continue to produce more flowers. Small flowering perennials, such as” Moonbeam ” Coreopsis, can be quickly and easily pickled with a hedge trimmer instead of cutting individual flowers. At the end of summer, when flowering decreases, stop Deadheading so that a few flowers can reach the seed. Seedling heads provide valuable food for birds and cause interest in the winter garden.
Fantastic Autumn Flowers:
Black-eyed Susan ‘golden storm’ (Rudbeckia fulgida ‘golden storm’, Zones 3 to 9). Widely considered one of the best perennials of all time, “Goldstrum” lights up the after summer garden with weeks and weeks of bright colors that last until October. Each Coneflower-shaped flower has a raised chocolate brown central cone surrounded by golden petals. Drought tolerant plants grow to 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). Maiden grasses 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 girl grass that grows three to four feet tall and changes from light green to bright red-orange in early autumn. Attractive feathers are silvery white and remain on 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 from the previous Season are cut off before fresh growth occurs.