Mum About Asters

Images: Light lavendar is a native Illinois aster, purple and bright pink are hybrid asters, and the gold is an annual mum.

For autumn color in the garden, you can’t beat the Aster family. The stiff stemmed plant with daisy like flowers blooms from August through October.

Wildflowers, Bush Aster (Aster dumosus), Calico Aster (Aster lateriflorus) and Frost Aster (Aster pilosus) have white to pale lavender rays surrounding a pale yellow disk. The Calico and Frost are Illinois native flowers. These asters are the parents of many beautiful hybrids.

The aster spreads easily but is seldom considered invasive. The seeds are distributed by the wind. Some hybrids spread by rhizomes. To increase the area where the wildflowers bloom, gather dried seed heads and simply toss in an area where you want flowers.

Mature plants attract many kinds of beneficial insects, including bees, wasps, flies, moths and butterflies. Because asters are one of the last blooming flowers before frost, they are a valuable source of pre-winter nourishment for many insects.

Asters prefer light shade and moist conditions. Growth is best in moist rich organic soil but will do well in clay because it retains moisture. The hybrids are more tolerant of full sun and dry conditions. You are probably seeing asters in places you’ve never seen them before due to our very moist spring and summer.

Asters are from 1-3 foot in height. The hybrid varieties are typically more bushy and shorter. Asters may be pinched back a couple of times during the summer months to keep them from becoming “leggy.” Do not pinch after they set flower buds.

Native wildflower asters have no scent although many hybrids are aromatic. Color has also been bred into hybrid asters. Purples and magenta are but two of the very colorful varieties. Size and form differences are also a result of hybridization.

Perennial mums are also from the aster family. These are the mums you see in nurseries in the spring although they typically bloom in the fall. The mums found in stores in the fall should be considered an annual.

Annual mums are particularly useful for fall decoration: In pots, used with pumpkins and gourds, placed with corn stalks, and even in the house. Do not allow the soil to become dry.

If you desire the perennial variety, make sure to ask at the nursery if they are hardy to our zone 5. Even then, they may need to be planted in a protected area and you can expect to lose some if we have a particularly severe winter. A protected area could be under the outer edge of an evergreen bush, a foundation plant, or on the south side of a building, fence or trellis.

Asters cut well and stay nice in a vase for weeks.

Whether you have native or hybrids asters, the autumn colors will enhance your garden. Add plant fall blooming asters to your spring “to do” list!