Chrysanthemums, or mums as they are often called for short, are staples for fall color in the Midwest landscape. Now is the time to plant them in Kansas gardens — cooler days are already here and the official first day of the season is just a few weeks away on Sept. 22.
Mums’ popularity for fall plantings comes from their long, late bloom season and the wide variety of colors available. When many flowers have finished blooming, mums have just begun. Some varieties will maintain their blooms until temperatures drop well below the freezing point later in the fall. Mums have flowers that are white, yellow, gold, bronze, pink, red, green and many shades of and between these colors.
When selecting mums at the garden center, select a plant that is the appropriate size to fill the container it will be planted in or the space it will fill in the landscape or garden. The plant is as big as it is going to get this year, and it should be enjoyed for what it is now (unlike a tree that is planted for what it will be years down the road).
Look for colors you enjoy and/or that complement other plantings in your garden, your home, containers in which they will be planted, etc. Cultivars rapidly come in and out of style, so it may be hard to find the same variety from year to year. Focus more on color and style — mums are usually sold with plant tags bearing pictures of the flowers for guidance. Newer cultivars offer more flower shapes and sizes and more 2-toned blossoms.
Mums look great mixed with ornamental grasses, pumpkins, gourds, straw bales, corn stalks, scarecrows, and other fall garden display items. They can also be planted en masse to create striking blocks of color. They grow well in containers or directly in the ground.
A common question about mums is whether they are perennial/hardy in Kansas. Mums are hardy enough to survive the winter and can certainly be kept as an all-year round plant in the Kansas garden. They need a lot of extra care to be kept, though, so many gardeners prefer to treat them like other annual plantings and enjoy them for a single season.
Gardeners who want to try to keep mums over the winter and through more seasons should cut plants back to a few inches after blooms fade in late fall to early winter. Mulch over the tops of the plants to provide extra insulation and continue to water deeply and infrequently through the winter as needed in dry periods.
Overwintered mums benefit from supplemental fertilization applied in spring at the first signs of new growth. At that point, gardeners may also be interested in dividing plants. Since potted mums may have extensive root systems in light potting media, digging up the plants and cutting them into 2 or more sections allows roots to expand into the surrounding garden soil rather than being caught in a tight ball. Dividing in this manner also provides additional plants for the garden.
Overwintered mums need to be pinched or sheared until about the first of July, or use the Fourth of July holiday as a reminder. Pinching or shearing removes the stem tips and encourages plants to get bushy instead of tall and leggy. Pinching or shearing prevents early flowering.
— Jennifer Smith is a former horticulture extension agent for K-State Research and Extension and horticulturist for Lawrence Parks and Recreation.