Add fall color to your garden

By Debbie Nelson, Master Gardener, U of M Minnesota Extension Service, Hennepin County

Fall colors usually mean the crimson, orange and gold of the trees of autumn. But autumn is not without its share of the pinks, blues and purples of blooming and colorful plants–the most common being chrysanthemums and asters.

“Mums” come in a myriad of colors from white, pink and purple to yellow, orange and burgundy. They range in size from dwarfs to the shrublike Maxi-Mums™ developed by the University of Minnesota. If planted in a sunny location and well-drained soil, and provided winter protection, mums can provide a bouquet of color in your fall garden for many years. In wet soils, they will exhibit poor growth and may suffer winter kill. In shadier spots, the plants will be taller and spindlier and most likely will bloom later.

Garden mums in containers can be planted almost anytime, spring, summer or fall. You can also propagate mums from rooted cuttings, divisions or rooted suckers, but these are best planted in the spring in order to give them enough time to develop a strong root system and bloom in the fall. Plant the plants 18”-24’ to allow for plenty of air circulation and add peat moss, compost or manure to the soil when planting. Water the plants if the soil becomes dry soaking it 6”-8”, but avoid standing water.

Mums should be ‘pinched back’ early in the growing season. Pinching off the tips will produce bushy, compact plants that will provide more blooms. Continue to pinch back early blooming varieties until mid-June and until July 4th for September bloomers. Mums are susceptible to several diseases and pests, including septoria leaf spot, powdery mildew, leaf hoppers, leaf miners and aphids. The best way to avoid these threats is to inspect your plants for pest or disease before you purchase them. Plant them where they will receive plenty of sun and far enough apart to allow for good air circulation, and weed your garden regularly and remove other diseased plant material.

Most mums are frost resistant but vary widely in cold hardiness. The University of Minnesota has produced numerous varieties of cold hardy chrysanthemums over the last 50 years, including MinnAutumn, Minnglow, Minngopher, Minnpink, Minnqueen, Minnrose, Minnruby, Minnwhite and Minnyellow. They range in color from white, yellow, pink, red and bronze, and bloom between early and late fall. Whatever the variety winter protection is critical. After the have finished blooming, cover the plants with 4-6” of shredded leaves, hay, straw or evergreen boughs.

Asters are another fall blooming plant. They produce daisy-like flowers in white, pink, blue and purple. They can range in height from less than 1’ to more than 2’, like the New England Aster. Asters benefit from being pinched back, just like mums, and from adding compost or fertilizer to the soil. They are more tolerant of dry periods, but prefer moist, but not wet, soil. Because of their sturdy stalks they are ideal for cutting for bouquets.
With a little bit of planning in the spring you can add your own color to the fall landscape.