Many gardeners are continually on the lookout for the newest compact cultivars to add to their gardens. Maybe it is because after years of gardening they are running out of room. Perhaps they have moved to a downsized home with a downsized garden. Or maybe their hearts just soften at the sight of little cuties and reckon they can always find room for one more petite perennial.
While I enjoy smaller versions of perennial favorites as much as the next gardener, I adore the big guys – those perennials that grow more than 4 feet tall. Some might shy away from tall perennials, fearing their stems may flop about the garden. And sure, there may be some high-maintenance perennials in the 4-foot-and-over category, but there are also plenty of tall plants with stems strong enough to stand defiantly upright, even in summer thunderstorms.
Some of these towering perennials are most attractive when massed; others are beautiful planted as specimens. Generally, the more substantial and dense the form of the plant, the more likely it can go it alone. Large perennials with open habits often look better when planted in a group.
One of my current favorite perennials, Aralia ‘Sun King’ grows to gigantic proportions in my landscape. Plants growing in more shade top out at 3 feet, but the specimens growing with a bit more direct sunlight are shooting up to 5 feet tall!
Their leaves emerge bright gold in spring and retain their color if they receive a few hours of direct sun each day. In shadier situations, their foliage turns chartreuse. Aralia ‘Sun King’ is a lovely choice to plant as a specimen. Its large, colorful foliage and bold habit adds a ray of sunshine anywhere its planted.
If you need a tall perennial for a lightly shaded spot, check out Aruncus dioicus, or goatsbeard. It resembles an astilbe on steroids – the same lacy foliage and fluffy flower spikes in exaggerated size. It grows 4 to 6 feet tall in moist, compost-enriched soil and blooms in spring. Goatsbeard can also thrive in full sun with consistent moisture.
The fine-textured, shrubby form of Boltonia asteroides is covered with tiny, white, daisy-like flowers from late August to mid-September. Commonly called false aster, it grows 5 to 6 feet tall. For best performance – growth, stem strength and flowering – plant this pollinator favorite in full sun and well-drained soil that has been amended with compost.
If you have inherited false asters that haven’t been sited properly and their stems flop, try cutting them back by a third in late spring. They will be shorter, but they’ll stand upright. ‘Snowbank’ is a shorter version – just 3 to 4 feet tall – so while it doesn’t make this list of tall perennials, it is a very nice selection.
I love the Eupatorium family, many of which grow very tall. The strong stems of Eupatorium maculatum, commonly called spotted Joe Pye weed, grow up to 6 feet tall. Clusters of dusty rose-colored flowers bloom in July and August. Given the full sun and rich, moist soil it prefers, it may spread so give it some room in the garden. If full sun is unavailable in your landscape, grow Eupatorium purpureum, or sweet Joe Pye weed. It is similar in both size and flower color but prefers open woodlands and average to moist soil. Butterflies, bees and other pollinators find them both irresistible!
Invite royalty to take up residence in your garden. Queen of the prairie (Filipendula ‘Venusta Magnifica’) is a show stopper in part to full shade. It has coarse leaves on robust, 5- to 6-foot stems topped with baby pink flower plumes from early to mid-summer. Flowers remain attractive even as they age.
Queen of the prairie is an ideal candidate for massing. Plant some in moist to wet soil. It thrives by a drainage ditch in my landscape.
The tropical-looking blossoms of perennial hibiscus (Hibiscus moscheutos) add a bold punch of color to the summer garden. Late to break dormancy in spring, they quickly grow 4 to 6 feet tall. Cultivars bloom in a wide range of colors, including pink, red, lavender and white. Plant perennial hibiscus in moist soil in a spot with full sun for the most blooms.
Rudbeckia ‘Herbstonne’ is another sun-loving perennial with commanding presence, soaring to nearly 7 feet and covered with large, golden yellow, daisy-like blossoms from mid-summer to fall. Grow it in moist, compost-amended soil in full sun. Get a step ladder and deadhead spent flowers to encourage more blooms.
I love Thalictrum rochebrunianum. Commonly called meadow rue, its foliage looks like an oversized columbine, and its tiny flowers float over the foliage like a lavender-purple cloud in mid to late summer. Plants grow 4 to 6 feet in full sun to part shade. Meadow rue is jaw-dropping gorgeous when planted in mass.
Take flowers and foliage to new heights in your landscape by planting tall perennials. Share your favorite tall perennials and garden with me!