The spring and summer months keep gardeners busy with soil preparation, planting and associated gardening maintenance chores. The rewards are non-stop flower production through the dog days of August. As summer winds down, however, many perennials have already bloomed. Flowering annuals have exhausted their resources. Finding plants that are in season in September will keep the garden going during those shorter daylight hours and cooler nights.
Bugbane 'Pink Spire'
Bugbane (Actaea) 'Pink Spire' is a buttercup family perennial hardy to minus 30 degrees Fahrenheit. Standing up to 4 feet high with a 1-to-2-foot spread, 'Pink Spire' has a 2-foot high mound of airy, compound, toothed purple-bronze foliage. Its leaves make this plant an attractive garden addition even when it's not in bloom. In August and September, stems rising above the foliage have pale pink spikes of brush-like flowers. The flowers spires may curve toward bright light.
This usually insect-and-disease-resistant plant may develop rust or leaf spot, or suffer from leaf scorch in dry soil. Use it, advises the Missouri Botanical Garden, as a tall plant in the rear of your perennial border or shade garden. Plants make the best impression when massed. Give 'Pink Spire' partial to full shade and fertile, evenly moist, well-drained soil. Protect them from strong wind.
Sneezeweed (Helenium) 'Bruno' is a late-summer and fall, aster family perennial. Forming clumps up to 4 feet high and 18 inches wide, it's hardy to minus 40 degrees Fahrenheit. 'Bruno' has 6-inch, lance-shaped deep green leaves. From August to October, its stiff stems have clusters of bronze-centered, 2-inch blooms with mahogany-colored rays (petals). Plants may develop rust, leaf spot or powdery mildew but are otherwise relatively problem free.
Use 'Bruno,' suggests the Missouri Botanical Garden, in a perennial border or in wildflower gardens. Give it full sun and moist, rich soil. Cutting plants back in June will control their height, increase branching and produce heavier flowering. Removing dead flower heads will prolong the flowering season. Divide the plants periodically when bloom decreases.
A bellflower family perennial, cardinal flower (Lobelia cardinalis) brings brilliant red blooms to the garden. Standing up to 4 feet high and 2 feet wide, this plant is hardy to minus 40 degrees Fahrenheit. Cardinal flower grows wild along streambeds and swamps and in moist woods. It has serrated, lance-like dark green leaves on unbranched stems. From July to September, the stems have upright spikes of bright red, tubular flowers that draw hummingbirds to the garden.
Use this problem-free plant, suggests the Missouri Botanical Garden, in a native plant or woodland garden or in the perennial border. Give it full sun to partial shade--best where summers are hot--and fertile, consistently moist to wet soil. Divide large clumps in spring to promote better bloom.