Garden Blog

Fall for Mums this year!

Fall is the natural time for garden mums to flower and their bright colors and tight plant habits make delightful additions to containers, color pots, and perennial beds. They are delightful pick-me-ups for the garden this time of year when the annuals are spent or dead after the first frost. 

What’s unique about the Mammoth Mums™? In the second and subsequent years of growth, each plant will grow to a larger size than normal—as much as 2’-3’ tall and 3’-5’ wide! Thus, they can be used as brilliant accents in your landscape and in large containers as specimen plants. You can also plant them in the ground and they can form a large hedge when they’re spaced 1’-2’ apart. These plants do not need pinching during the growing season but will naturally produce a hemisphere shape edged with flowers in the fall.

Here are some answers to frequently asked questions about garden mums:

• When is the best time to plant hardy mums in the garden? Spring. If you want to plant them in the fall after you’ve enjoyed them in containers, then plant them no later than mid-late October before the soil freezes. Be sure to mulch heavily around the crown of the plant so that the soil stays warmer for root growth and prevention of frost heaving.
• When should I cut the tops back? Everyone’s tendency is to cut these back after the first freeze. However, our milder winters (less snow cover) mean that it is best to cut the tops back in the spring so that they can act as a ‘snow fence’ during the winter months and catch as much snow as possible.
• Why did my mums flowers so soon this year? Due to the cold summer that we had, many of the mums flowered unseasonably early. This was an unusual year and, hopefully, next year will be warmer!
• Are all ‘hardy mums’ really hardy? No! Every retailer seems to sell them this way, but to be sure that you’re purchasing perennial, rather than annual, mums—read the label! If they say ‘Mammoth™’ or are in the ‘Minn’ series then they’re hardy. Most of the U of Minnesota mums are hardy in USDA Zones 3-4.
• Why didn’t my plants flower very much? Most likely this is due to not enough sunshine (mums need to be planted in full sun). Partial shade will cause a delay in or even stop flowering. Also, too much fertilizer (especially Nitrogen) will create lush plant growth and less flowers.
• Can I divide my mums and when? The best time to divide mums is in the spring when the new shoots have started to emerge from the rhizomes. It can also be done in the fall, but there is less chance for survival if it’s done too late or the root system doesn’t become established in the soil prior to when the ground freezes solid. Note, however, that any patented cultivars cannot be divided as that violates the U.S. Plant Patent laws!
• How can I ensure good winter survival? ‘Survival of the fittest’ comes into play here….plant them in the spring (rather than fall), feed and water them throughout the growing season (to maintain healthy, vigorous plants), don’t remove the dead above-ground stems until spring (see above), and mulch! Mulching is good gardening…it ensure cool soil temperatures during the summer, keeps water in the soil longer, stops weed seeds from germinating (more time to enjoy the garden than pulling weeds), and insulates the upper soil layer during the winter.

Happy Gardening, one and all!