It's a challenge to design a flower garden with the right combination of plants that look vibrant throughout the summer. You can count on many annuals to perform well right up until frost, but most perennials produce flowers for two, maybe three weeks, then call it quits. And it's not at all unusual for flower gardens to peter out toward the end of the season. Luckily, there are some terrific perennials that can add pizazz to your garden in summer's waning days.
Sure, you know about the many garden mums that bloom reliably each August and September. But here are a few other late-flowering favorites.
New England asters (Aster novae-angliae) and New York asters (Aster novae-belgii) are just two of the many types of asters that are extremely hardy (in fact, they're hardy to 40 below). Though some cultivars are only about 18 inches tall, many will grow to a height of 4 or 5 feet. In bloom, they're quite spectacular, covered with clusters of semidouble blossoms in shades of white, pink, lavender, purple or rose-violet.
'Purple Dome,' a compact plant with tiny, dark purple blossoms, and 'Alma Potschke,' a 3-foot plant with bright, salmon-pink blooms, are standouts among the New England asters. 'Wonder of Staffa,' a popular Frikart's aster, has larger lavender flowers, beginning midsummer, but is hardy only to 20 below. It's usually short-lived here, even with winter protection.
Going to weed
Until recently, Joe-Pye weed (Eupatorium maculatum or E. purpureum) was considered a weedy wild plant, rarely seen in cultivated gardens. Now it's prized for its stature (plants may grow from 4 to 7 feet tall) and dramatic, huge clusters of rosy to pinkish-purple flowers. Joe-Pye weed begins to bloom in late summer and continues to bloom up to eight weeks or the first real frost.
These hardy plants will thrive in moist soil, but it's not an absolute necessity. A bonus: Their fragrant flowers attract butterflies.
Here's to Helen
Helen's flower (Helenium autumnale) produces blossoms similar to smaller coneflowers, but in rich, warm, fall colors -- golden yellow, butterscotch, red-orange and mahogany. Its other name, "sneezeweed," has probably prevented some people from planting it, but the flowers won't make you sneeze any more than goldenrod, another late-blooming perennial with an undeserved bad reputation.
Like Joe-Pye weed, Helen's flower will also thrive in moist soil. Plants range from about 3 to 5 feet in height when grown in full sunlight. Most begin blooming in late summer and keep on until frost.
There's no common name for boltonia (Boltonia asteroides), which may be why it's not well known. It's a lovely plant, if you have room for it. In late summer, it becomes a billowy, 5-foot cloud of small, yellow-centered daisies of pink, lavender or white with delicate stems and small, slender leaves.
'Snowbank' is a particularly desirable cultivar that's a bit more compact, growing 3 to 4 feet tall. Its pristine white blossoms contrast beautifully with the more intense colors of asters, mums and other fall flowers.
Russian sage (Perovskia atriplicifolia) combines lacy, silvery foliage with long, branched plumes of lavender blooms. It starts blooming in midsummer, but becomes even lovelier heading into fall, when its flower-covered stems elongate and send out more side shoots.
This plant can grow to a height of 4 or 5 feet in full sunlight, but becomes taller and floppier when grown in partial shade.