Chrysanthemums, often called mums, are a staple in autumn gardens, providing a burst of color when most other flowers have faded. Understanding the plant’s appearance before it flowers is key to successful cultivation. Identifying the plant during its vegetative growth phase and recognizing the subtle changes that signal impending bloom allows gardeners to provide the specific care needed for a spectacular fall show.
The Vegetative Stage (Foliage and Growth)
During the spring and early summer, the chrysanthemum plant is in its vegetative stage, focusing energy on producing stems and foliage rather than flowers. The leaves are a primary identifying feature, typically presenting as deeply lobed and serrated along the edges in a dark green color. This leafy growth is dense and full, creating the characteristic bushy, mounding habit of a healthy mum plant.
The foliage has a distinct texture and aroma, often being slightly fuzzy or aromatic when handled. Stems begin as herbaceous (soft and green) but develop a tougher, slightly woody base over the growing season. The plant’s structure during this phase involves vigorous upward and outward growth, with new shoots continually emerging.
The Budding Process (Pre-Bloom Transformation)
The transition from a leafy plant to one ready to bloom is triggered by shortening day length in late summer and early fall. Chrysanthemums are classified as short-day plants, requiring less than 12 hours of daylight to initiate flower bud formation. This photoperiodic signal causes growth at the stem tips to shift from producing leaves to developing flower structures.
The first visible signs of budding appear as tiny, compact, green structures emerging from the leaf axils (where leaves meet the main stem) and at the stem tips. These developing buds are initially small and tightly enclosed by sepals, which are protective modified leaves. At this stage, the buds are generally spherical or slightly conical.
As the buds mature, they swell noticeably but retain their green color, showing no hint of the final flower hue. Buds often form in tight clusters at the top of each stem. The central, or terminal, bud is typically the largest and opens first, indicating the final stage before the flower begins to unfurl.
Care and Timing for Successful Blooms
The plant’s appearance during the vegetative stage is influenced by “pinching.” Pinching involves removing the top inch of new shoots in the spring and early summer to encourage side branching. This practice leads to a fuller plant with many more flower-producing stems. Pinching is generally continued until about mid-July to ensure the plant develops a compact shape before bud set begins.
The timing of this care is important because the plant needs approximately 100 days of undisturbed growth before the desired bloom time. Once flower buds are visibly forming in late summer, the focus of fertilization shifts away from promoting green growth. Gardeners typically stop applying high-nitrogen fertilizers and may switch to a formula higher in phosphorus to support the developing blooms.
Bud initiation is dictated by the environment, as the plant responds to decreasing daylight hours. This environmental cue means the plant will naturally begin to set buds in late summer, regardless of cultivar. Providing full sun exposure is necessary to ensure the plant receives the correct light signals and has the energy needed to produce healthy, vibrant buds ready to open with the cooler temperatures of autumn.