Chrysanthemums, often simply called mums, are a popular fixture in gardens, providing a welcome burst of color as the growing season winds down. These late-season blooms offer a vibrant display when most other flowering plants have faded. The duration of this spectacular autumn showing depends heavily on the specific variety and the conditions they experience. Targeted care can maximize the bloom period.
Typical Length of the Bloom Cycle
A single chrysanthemum plant typically provides a continuous visual display for a period ranging from four to eight weeks once the buds begin to open. This duration is highly dependent on the plant’s genetics and the external environment. The wide variety of available cultivars means bloom times are staggered across the fall season.
Garden mums, which are bred for hardiness, generally offer a robust but slightly shorter and more intense bloom period. Florist mums, often sold in pots for temporary display, are cultivated for an abundance of large flowers and tend to provide a show closer to the eight-week range under ideal conditions. Selecting a mix of early, mid, and late-season varieties can extend the chrysanthemum color in a garden from late summer until the first hard frost.
Environmental Factors Affecting Duration
Chrysanthemums are classified as short-day plants, meaning their flowering is triggered by the reduction in daylight hours that naturally occurs in late summer and early fall. Once the period of uninterrupted darkness lengthens sufficiently, the plant initiates bud formation, leading to the autumn bloom. The specific timing of the bloom cycle is determined by the cultivar chosen by the grower.
Temperature is the primary external factor influencing how long the flowers last once they open. Cool, consistent temperatures above freezing are the most favorable conditions for prolonging the display. These cooler temperatures slow the metabolism of the plant and the aging process of the flowers.
Conversely, an unexpected heat wave during the blooming period can drastically shorten the flower life. High temperatures cause the flowers to mature and fade quickly. Protecting the plants from intense afternoon sun can mitigate this heat stress and help preserve the blooms.
Practical Steps for Prolonging the Flowers
The most effective action for extending the bloom period is deadheading, which involves removing the spent, faded flowers. This practice forces the plant to redirect its energy away from the production of seeds and towards developing remaining unopened buds. By preventing the plant from completing its reproductive cycle, the gardener prolongs the season.
When deadheading, remove the entire faded flower head by pinching or cutting the stem back to the nearest set of healthy leaves or an emerging side bud. Performing this task regularly, perhaps once or twice a week, will maintain a tidy appearance and ensure that the plant’s resources are efficiently channeled into future flowers. For a mass of spent flowers, a light shearing of the top layer can quickly remove the bulk of the dead material, exposing the lower, unopened buds to light.
Consistent moisture in the soil is important for sustaining the bloom, especially when the plant is actively flowering. Allowing the soil to completely dry out stresses the plant and can cause the flowers to wilt and prematurely drop. However, avoid overwatering, as overly saturated soil can lead to root rot and quickly end the life of the plant.
Placing the plants where they receive morning sun and are shielded from the intense heat of the afternoon can help prevent the flowers from scorching and fading quickly. Finally, the chrysanthemum’s display will immediately cease with the arrival of a hard frost, which causes cellular damage to the foliage and blooms. Moving potted mums to a sheltered location or covering in-ground plants on nights when a hard freeze is predicted will protect the remaining flowers and maximize the number of weeks you can enjoy their color.