Chrysanthemums, commonly known as mums, are a signature plant of the autumn season, typically purchased as dense, potted arrangements for porches and patios. The longevity of their display is a frequent question for consumers who want to maximize their investment in fall color. The duration of the blooms depends on understanding the plant’s biology and environmental needs.
Understanding the Potted Mum Bloom Cycle
The expected bloom duration for a potted mum ranges from four to eight weeks once the flowers begin to open. This range depends significantly on the plant’s maturity level at purchase; choosing a plant with many tight, unopened buds provides the longest display. Mums are naturally short-day plants, initiating flowering as nights lengthen in the fall. Commercial growers manipulate this cycle using artificial darkness to force plants into bloom earlier for the market.
Deadheading is an effective way to extend the visual display. This simple process involves removing the spent, faded flower heads. This action prevents the plant from diverting energy into seed production. Instead, the plant redirects resources toward encouraging secondary flower buds to open. This continual removal keeps the plant tidy and allows for a fresh succession of blooms over several additional weeks.
Environmental Influences on Bloom Longevity
Temperature management significantly affects how long a mum stays in bloom. Chrysanthemums prefer cool temperatures, ideally between 50°F and 65°F. Exposure to temperatures consistently above 70°F rapidly shortens the blooming period and causes premature fading. Conversely, a hard frost can quickly damage the petals and foliage, abruptly ending the display.
Potted mums require consistent and even moisture, as their dense root systems and container environment cause them to dry out quickly. Inconsistent watering, whether over- or under-watering, causes stress that leads to flower drop and wilting. Overwatering can lead to root rot, while dry soil causes severe wilting, both shortening the life of the blooms. Check the soil by feeling an inch below the surface; if it is dry at that depth, the plant needs water.
The placement of the pot regarding light also plays a part in flower preservation. Mums need bright light, ideally receiving at least six hours daily to maintain vibrant color. However, intense, direct afternoon sun, especially in warm temperatures, can scorch the flowers and cause them to deteriorate quickly. Positioning the pot in bright, indirect light or morning sun with afternoon shade is the best strategy for maximizing their lifespan.
Transitioning the Potted Mum Post-Bloom
Once the blooms have faded and the foliage has browned, the plant enters its dormant phase. Mums are perennials, meaning they can return the following season if properly cared for during the winter. Owners must choose between disposal or attempting to save the plant.
To prepare the mum for overwintering, cut the stalks back to three to six inches above the soil line. The pot should then be moved to a protected location, such as an unheated garage or basement. The storage area needs to remain cool, ideally between 32°F and 50°F, to keep the plant dormant.
During dormancy, the plant requires very little water, typically a light watering about once a month, only to prevent the roots from completely drying out. For the best chance of survival, plant the mum directly into the garden bed at least six weeks before the ground freezes, allowing the roots to establish before winter dormancy. If planting is not possible, burying the pot in the ground provides better insulation for the roots than leaving the container exposed.