Champaign, IL - U of I Extension Horticulture Educator Ryan Pankau talks mums.
Mums (short for chrysanthemums) are one of the quintessential fall flowers in Midwestern gardens. They are readily available in garden centers this time of the year and offer a wide variety of beautiful colors. Most all varieties for sale are hardy mums, meaning they are perennials that will survive our winters and flourish again next growing season.
Spring planting of mums is recommended to ensure winter survival in our area. However, fall planting is most often done as they are readily available in fall. It can be successful with some additional considerations. During milder central Illinois winters, mums should have no problem surviving, but in colder winters, with temperatures dipping into the single digits more often, mums may be at risk of winter kill.
The reason mums die in winter is that their shallow, fibrous roots system may get frozen as the upper soil layer freeze and thaw over winter. When mums are planted in fall, their root system may still be fairly small when winter sets in, as opposed to spring-planted mums which have an entire growing season to develop a larger roots system. So, anything we can do to promote extensive root growth before winter is important.
As with all newly planted plants, watering is important. Pay attention to fall rains and if we wind up with a dry fall, some watering will be needed. Another important consideration is planting location (which goes for both spring and fall plantings). Mums prefer well-drained soils and full sun. They cannot be planted in a poorly drained area as root growth will be limited by soil conditions. In addition, full sun is needed for these plants to thrive and produce large, extensive roots. If you can find a more protected area in your yard, one that is closer to your home, south facing, and less exposed to wind and shade, pick one of those sites.
One huge help for both fall and spring planted mums is mulching. Plan to mulch your mums at the end of fall as blooming begins to wane. Mulch them with wood chips or straw to a depth of about 4inches. Leaves are not the best mulch as they tend to flatten and stick together over time, offering less insulation.
Mums are not the only beautiful plant for you garden in fall. They are members of the aster family, so other asters do provide excellent, showy flowers in fall. A lot of other asters provide more height than mums, which are typically on a few feet tall. New England Aster, native to Illinois, can get up to 5-6 feet tall and provide multitudes of beautiful fall flowers.
There are several varieties of sedum that provide wonderful fall flowers. ‘Autumn joy’ is one of my favorites. Sedums are shorter in stature than New England Aster, only reaching 2-3 feet in height, similar to mums.
If you are looking for a plant that provides beautiful foliage, as opposed to showy flowers, consider planting ornamental kale in fall. Although it is rarely perennial, so it typically won’t survive our winter, these plants come in variety of colors and provide beautiful dark blue-green, red, purple and pink foliage. They are relatively inexpensive for the beauty and variety they add to our fall gardens.