Asters are the last great show of the season
Updated: 5 hours ago
In September at Thuya Garden as the garden symphony of colors slows down, and the crescendo has been heard, a new cadence of the garden begins – the blooming of the perennial New England aster, Symphyotrichum novae – angliae, begins. The asters’ blooms serve as a colorful bridge for our eyes through the fall season, preparing us for the browning end of autumn. The bright colored blooming continuum says, “Wait, it’s not quite over yet!”
New England asters may be among the most familiar native wildflowers in North America, but their value to the landscape is extraordinary. They are considered a keystone species and provide critical support for pollinators and birds at a time of year when many other plants have finished blooming. Their vibrant blues, purples, pinks, and whites bring a final burst of color to the garden just as autumn begins to settle in.
The New England aster flower itself is worthy of description. As aptly described by PlantNative:
The flowers are the plant’s crowning glory – numerous composite flower heads arranged in dense, flat-topped to dome-shaped clusters (corymbs) at the stem tips. Each flower head is 1 to 1½ inches across, composed of 30-50 narrow ray petals (technically ray florets) surrounding a central disc of tiny yellow tubular florets.
There are four asters at Thuya Garden, all with sunny center discs. These asters provide a wonderful melody of color – magenta pink petals of the cultivar ‘Alma Potschke,’ the cooler blue violet tones of the cultivar ‘Skyscraper,’ the soft whites of ‘Chilly Winds,’ and the straight native species – taking us through fall until the cold and shortened days are here to stay.
‘Skyscraper’ is the first to bloom in the fall, usually around September 1. The remaining three asters will follow suit, beginning to bloom approximately the second or third week of September. ‘Skyscraper’ is a long bloomer, starting with a few at first and increasing each day. Its delicate bright periwinkle blue petals surround the sunny yellow center and provide a colorful dome-like mass higher up in the larger, deeper Thuya border. It is four to five feet tall with a width/spread of three to five feet. Some staking or brushing for stability is often needed to keep them corralled a bit. We had two plants in early September.
The straight native species Symphyotricum novae – angliae grows three to six feet high with a width span of two to three feet. We have one plant at Thuya that pairs nicely next to one of the ‘Skyscraper’ asters. The different blue tones of each play nicely together. The one growing here averages four to five feet tall.
‘Alma Potschke’ cultivar features a fine petaled magenta or bright rose pink petaled bloom with the sunny yellow center. It is tolerant of wet soil conditions and is mildew resistant. It averages three to four feet in height and two to three feet wide across the top, occasionally reaching four feet across as ours have. We had two plants in early September.
New England asters are the showiest of the genus Symphyotricum. They have a lot going for them. Their cultivars are a hardy, adaptable perennial for the landscape and garden. They are tolerant of various soil and light conditions, and unpalatable to deer and rabbits. They provide a crucial late season nectar and pollen source for pollinators preparing for winter or, for fall migrations, when many plants have stopped producing. The pollinators that visit include butterflies, skippers, bees, and moths. The asters are a host plant for the Pearl Crescent moth caterpillar. Birds will forage the seeds from late fall through winter. Some do reseed into the garden beds, but we are easily able to identify and pull these in the spring and summer.
_______________________
Powdery mildew on asters is a common fungal disease that causes white or gray powdery spots on leaves and stems. This has not been a problem here at Thuya. The ‘Chilly Winds’ and ‘Skyscraper’ cultivars can often display the characteristic brown leaves midway down and to the ground after it has started blooming. Planting companion plants around it helps camouflage some of that. The ‘Chilly Winds’ is more extreme in the brown lower leaves than the others in our experience, with ‘Alma Potschke’ having the least.
For maintenance of the New England asters here at Thuya, we place metal round supports with the grid pattern on most of them in the spring. This provides some directional support near to the ground, which we find helpful. Selecting an appropriate size is necessary. We also prepare to use large pea brush later on for some corralling; occasionally a bamboo and twine surround is needed.
At Thuya Garden, these asters create one of the season’s most memorable displays, alive with butterflies, bees, and other late-season visitors. We hope you will visit this fall and enjoy their beauty for yourself while experiencing one of nature’s last great garden performances before winter arrives.
Story by Wendy Dolliver, Thuya Garden Head Gardener; Photos by Wendy and Eddie Rivera, Thuya Seasonal Gardener
Comments