Chrysanthemums, often called mums, are popular ornamental plants cherished for their diverse forms and vibrant autumn blooms. Understanding their growth stages is key to successful cultivation and maximizing bloom potential. Native to East Asia and northeastern Europe, they offer a wide array of colors and shapes, from single daisies to large, showy flowers.
Early Development
Chrysanthemums begin life from a seed or a cutting. When starting from seed, germination requires consistent moisture and a warm environment. For cuttings, rooting occurs in a humid setting with indirect light, taking several weeks to develop a root system.
Young chrysanthemum plants require careful handling. They thrive in bright, indirect light and consistent moisture, without becoming waterlogged. Maintaining temperatures between 60-70°F (15-21°C) aids establishment. Once a small plant with true leaves has formed, it is ready for transplanting into a larger container or garden bed.
Vegetative Growth
This stage involves an increase in size, developing strong stems and lush foliage. During this period, chrysanthemums build energy reserves for future flowering. Healthy vegetative growth is shown by full, dark green leaves and sturdy stems.
Proper watering is important, encouraging deep root development rather than shallow surface roots. A balanced fertilizer, applied monthly, supports foliage development and plant vigor. Pinching, which involves removing the tips of young stems, encourages branching, leading to a bushier form and more blooms later in the season.
Budding and Flowering
As day lengths shorten, typically in late summer or early autumn, chrysanthemums transition from vegetative growth to forming flower buds. This photoperiodic response triggers blooming. Initially, buds appear as small, green nubs at stem tips, gradually enlarging and developing their characteristic shape.
During budding and flowering, the plant’s water needs increase, requiring regular and thorough watering to sustain the developing blooms. Fertilization should shift to a formula lower in nitrogen and higher in phosphorus and potassium to promote flowers over foliage. Controlling light duration, such as providing 12-14 hours of darkness, is important for optimal bud set and bloom timing, especially for specific varieties. Deadheading, the practice of removing spent flowers, encourages more blooms and can extend the flowering period.
Post-Bloom and Dormancy
After the vibrant display of flowers concludes, as temperatures drop and days shorten, the chrysanthemum naturally prepares for its resting phase. The foliage yellows and dies back as the plant channels its energy towards its root system.
For perennial chrysanthemums, cutting back spent stems to a few inches above ground conserves energy and prepares it for winter. Applying a thick layer of mulch around outdoor plants provides insulation and protects roots from freezing temperatures. During dormancy, the plant requires less water due to reduced metabolic activity, conserving energy for spring growth.