Chrysanthemums, commonly known as fall mums, are a bright symbol of autumn, providing color when other garden flowers fade. Prized for their dense, mounding growth and wide array of shapes and hues, they are extensively used to decorate porches, patios, and garden beds. How long a mum lasts depends on whether it is treated as a short-term seasonal accent or a long-term perennial addition to the landscape.
The Typical Lifespan of Fall Blooms
The immediate lifespan of a fall mum, once purchased, typically ranges from four to eight weeks. This duration refers specifically to the current cycle of flowers remaining vibrant before they fade, depending on the plant’s condition and environmental factors.
To maximize the display, select a plant with numerous tight, unopened buds rather than one already covered in fully open flowers. A plant with mostly buds will gradually open its blooms over several weeks, extending the period of color. Conversely, a mum purchased at the peak of its bloom has already begun fading, limiting its remaining decorative life.
Temperatures also play a significant role in flower longevity. Extended periods of warm weather can cause the blooms to age and wilt more quickly. The ideal conditions for maintaining the bloom cycle involve cooler temperatures, which naturally align with the late fall season.
Essential Care Practices for Maximum Display
Consistent and appropriate care ensures a mum reaches the maximum end of its short-term bloom period. Mums are shallow-rooted plants, making them susceptible to drying out quickly, especially in containers. The soil should be kept consistently moist, but never waterlogged, to prevent plant stress.
When watering, apply water directly to the soil at the base of the plant, avoiding overhead watering of the foliage. Wet leaves can encourage fungal diseases, which shortens the display time. For optimal flowering, chrysanthemums require full sun exposure, ideally receiving at least six hours of direct sunlight daily.
A simple maintenance technique known as deadheading is crucial for extending the bloom time and improving appearance. This involves pinching or snipping off spent, faded flowers down to the nearest set of healthy leaves or new buds. Removing these aging blooms signals the plant to produce new flowers rather than setting seeds, encouraging a continuation of the floral display.
Understanding Long-Term Survival and Overwintering
The potential for a mum to survive past the current season depends on whether it is a “florist” mum or a “garden” mum. Florist mums are often forced to bloom early and are not bred for hardiness, meaning they are treated as seasonal annuals. Garden mums, however, are typically hardy in USDA Zones 5 through 9 and can survive winter to return in subsequent years.
For a perennial garden mum to successfully overwinter, it must be planted early enough to establish a robust root system before the first hard frost. Planting in late August or early September allows sufficient time to anchor itself. Late fall plantings often fail because the plant is focused on flowering, not root development, which is why many fall-purchased mums do not return the following spring.
Once the plant has finished blooming and the ground freezes, apply a thick layer of mulch (three to four inches deep) around the base. This helps insulate the root crown from extreme temperature fluctuations. The dead stems should be left intact until spring, as they provide additional protection and help the plant survive.