Asters add brilliant life to the fall garden

Purple Dome Asters
Purple Dome Asters begin to bloom in mid-September and will last through the month of October. Photo taken on 09/25/20 by John Zvirovski

Asters are one of the best fall perennials to have in the garden next to the chrysanthemums. They have many great characteristics such as, they thrive in regular to clay soils, they don’t mind wet feet during the summer, and they tolerate cold temperatures quite well during the autumn season.

Most perennial asters bloom in early to late fall and have a variety of colors and heights that will fit any area of your garden. They do prefer full sun to keep them at their recommended heights as too much shade will make them tall and leggy. If they are planted in too rich of a soil, they will also tend to get taller than their normal range, causing them to hang over in some of the larger sizes.


Available in shades of white, lavender, blue, purple, pink and red, these are great plants to extend that rich color through the month of October. Most selections are mound forming, but some of the taller ones are not and tend to need staking in non-protected areas.

Based on their sizes, there are types that will work well for all areas of the sunny garden. If you are looking for border selections that do not get too tall, try the Woods Purple producing a deep purple flower, Woods Blue with its lavender blooms, Bonney Blue with its powder blue flowers, or the Pink Dome with its deep pink flowers. These selections reach about eight to twelve inches tall and about two feet around in a tight mound form. Their one inch blooms will literally cover the mounded plants with flowers for nearly a full month starting at the end of September.

For varieties in the middle portion of your garden, try Purple Dome with its rich purple blooms, Bonningdale White with its semi double white blooms, Aroma, and Eventide with its light purple flowers. These selections grow between eighteen and thirty inches tall. They create a larger mound formation of two to three feet around and are quite compact.

If you are looking for taller varieties for the back of your garden, choose from September Ruby or Alma Potschke with its deep pink flowers, Crimson Brocade with its nearly red blooms, or Bluebird with its light blue flowers. These selections are taller and bloom later in the season. Some of these types may need staking to keep them upright when they are in bloom.


One of the key techniques to learn with the fall-blooming asters it to pinch the ends of the plants back up until the fourth of July to promote numerous stems and multiple flower buds. This technique also creates a very compact plant that is resilient to weather events and becomes a beacon of color later on.

Perennial asters only need dividing every three to five years to keep them vigorous and healthy. As with most perennials, they will begin to die out in the center when they become too large or start to decline in vigor and produce less blooms at a shorter plant height. Easy to divide, I usually do this in the springtime when I lift them, break the roots ball apart into smaller plants and then replace them into the same place or a variety of places within the garden. These divisions will bloom within the same year they are divided.

Similar to chrysanthemums, when putting them to rest for the winter, make sure their roots are not sitting in moist soils through the winter as this will cause the roots to rot. Always pay attention when you are planting these perennials to make sure they are not in a poorly drained area so they can survive well from one year after the other.

Asters are great when planted in the fall-blooming flower bed that is mixed with annuals for summer color or planted in groupings throughout the seasonal garden within your landscape. However you want to use them in your gardens, they are a definite asset to extend the blooming season within your garden. In our short growing year, what better way to enjoy our plants’ blooms than by adding this autumn sensations.

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