We offer several true northern hardy varieties of Mums from the Mammoth™ series, including Mammoth™ Lavender Daisy, Mammoth™ Yellow Quill, and Mammoth™ Dark Bronze Daisy.
“Mums” are an autumn garden classic. Every fall, as the tree leaves begin to change their hue, customers come in looking to add colorful mums to their plantings. Along with the ever-popular seasonal fall mums, consider using winter-hardy mums for year-round interest.
Chrysanthemums (“mums”) are among the most popular flowers in the world. They are native to East Asia and have been described in writings as a cultivated plant in China as far back as the 15th century B.C.
Early Chrysanthemums were primarily yellow, and their name comes from the Greek words for “yellow flower”; chrysos (yellow) and anthemon (flower). Modern Chrysanthemums, however, come in almost every color, shape, and size. There are currently over 20,000 named cultivars of Chrysanthemums.
While the National Chrysanthemum Society recognizes 13 different classes of mums, the most important classification for northern gardeners is Florist Mum versus Garden Mum.
These are frequently sold as gift plants and are intended to be enjoyed as houseplants during their bloom period and are usually simply discarded after bloom. Long-stemmed florist mums are also grown for the floral trade since they make an exceptionally long-lasting cut flower.
These are often misleadingly labeled as “Hardy Mums” and are usually sold in autumn to add color to patio containers and front beds at a time when most perennials have stopped blooming. While many of these Mum varieties are indeed hardy, they are unlikely to overwinter in our northern gardens. This is because they are entering the winter in a weakened state. Growers pamper them in greenhouses throughout the season. In fall, when the plants are supposed to divert energy into root development to survive the upcoming winter, growers pump them with fertilizer to produce a profusion of flowers.
To improve the likelihood of your plants survive the winter, we recommend planting them in a protected spot and leaving the top growth alone through the winter. Once the soil freezes, apply a loose mulch (or evergreen boughs) over the top of your plants. This will minimize freezing and thawing, which can heave the roots out of the ground.
How do you know which Mums are hardy?
In general, the densely flowering mums that are offered for sale in full bloom in the fall should not be counted on to overwinter. You should find true winter hardy mums offered at garden centers alongside other hardy perennials, available throughout the planting season. Ideally, these should be planted in spring or summer to allow the roots a chance to establish before winter.
Our favorite of the reliable, winter-hardy mums are the Mammoth™ series. These were developed at the University of Minnesota and were bred for extreme cold hardiness and exceptional garden performance. Their habit is described as a “shrub cushion” because they grow quite large (36” x 36”), form even mounds without pinching and pruning, and are completely covered in flowers when in bloom.