The potted chrysanthemum, commonly called a mum, is the defining flower of the autumn season, providing a dense burst of color for temporary seasonal displays. Mums are often purchased in full bloom to decorate porches and patios, but their lifespan varies greatly depending on the environment and the post-purchase care they receive. The length of time you can enjoy your mum ranges from a few short weeks to many years, determined by whether the plant is treated as a temporary decoration or a permanent fixture. Understanding their specific needs is the first step toward maximizing their vibrant display life.
Factors Determining Bloom Duration
The typical lifespan of a potted mum display ranges from four to eight weeks once the flowers begin to open. The greatest influence on this duration is the plant’s condition at the time of purchase, making selection a crucial factor in longevity. To ensure a longer bloom time, choose plants heavily laden with tight, closed buds rather than those already featuring a full canopy of open flowers, as the latter have already expended most of their energy.
Temperature is another primary determinant of how quickly a mum fades, as these plants thrive in cool autumn weather. High temperatures, particularly those soaring into the 80s Fahrenheit, accelerate the bloom cycle, causing flowers to brown and wilt quickly. Mums perform optimally in cooler conditions, with temperatures around 61 to 65 degrees Fahrenheit supporting the longest, most sustained flowering period.
The type of chrysanthemum also impacts its potential lifespan. Garden centers sell two main categories: florist mums and garden mums. Florist mums are bred for large, showy blooms and are designed only for a short-term display life, unlikely to survive winter. Garden mums, conversely, are hardy perennial varieties that can withstand colder temperatures and have the potential for long-term survival in the landscape.
Care Practices to Extend Potted Life
The most impactful action to prolong the life of a potted mum is addressing its moisture needs, as these flowers are exceptionally thirsty. The dense root ball and small nursery pot cause the soil to dry out rapidly, often within a single day, leading to quick wilting and flower loss. Check the soil daily, watering thoroughly whenever the top inch feels dry to the touch, ensuring water runs out of the drainage holes.
To properly hydrate a thirsty, root-bound mum, submerge the entire pot in a bucket of water for about 10 minutes, allowing the root mass to fully soak up moisture. While consistent moisture is necessary, avoid letting the pot sit in standing water, which can lead to root rot and fungal disease. Repotting the mum into a larger, decorative container with fresh potting mix immediately after purchase helps mitigate the root-bound issue and provides greater soil volume to retain moisture.
Managing spent flowers, known as deadheading, is important for encouraging the plant to focus its energy on developing remaining buds rather than seed production. Simply pinch or snip off any blooms that are faded or turning brown, which keeps the display looking fresh and may stimulate a second, smaller flush of blooms. Mums require full sunlight, or at least six hours of direct sun daily, but protect the plant from intense afternoon sun, as this can scorch the foliage. Supplementary feeding is not necessary during the short autumn season, as the plants were heavily fertilized by the grower.
Moving Mums to the Landscape for Perennial Growth
To transition a potted mum from a temporary decoration to a permanent garden plant, the process must begin well before the harshest winter weather arrives. The best window for planting a hardy garden mum is approximately six weeks before the first hard frost is expected, which allows the root system sufficient time to establish itself in the ground. This process is most successful with the perennial garden mum varieties, as the tender florist types rarely survive the transplanting and overwintering process.
When moving the plant to the landscape, select a location that receives at least six hours of sun daily and features well-drained soil. Mums will not survive a winter in saturated soil, as waterlogged roots are susceptible to rot and death during the cold season. Dig a hole twice as wide as the pot the mum came in, gently loosen the tangled roots, and plant the mum so the top of the root ball is level with the surrounding garden soil.
After the mum has finished blooming, cut the stems back to a height of three to four inches above the soil line. This pruning helps the plant focus its energy on root development rather than maintaining dead foliage. Applying a thick layer of dry mulch, such as straw or shredded leaves, over the planting area provides insulation, protecting the crown and roots from severe temperature fluctuations throughout the winter months. Leaving the cut stems and mulch in place until new growth appears in the spring helps ensure the perennial returns the following year.