From our perspective as plants, timing is everything. We, chrysanthemums, are photoperiodic, meaning our flowering is triggered by the shortening daylight hours of late summer and early fall. Our internal biological clock senses the longer nights, which signals us to cease vegetative growth and shift all our energy into bud production. To ensure we are at our peak floral display for the autumn season, you must work with this innate rhythm, not against it. Planting too late disrupts this critical cycle and gives our root systems insufficient time to establish themselves before our energy is diverted to the demanding task of blooming.
The single most important factor for our success is a strong, well-established root system. When you transplant us from a nursery pot into your garden, we experience significant shock. Our entire world changes—the soil texture, moisture levels, and temperature are all new. We must immediately begin growing new roots to explore this new environment and anchor ourselves securely. This process of acclimating and establishing a robust root network is paramount. It is this system that will support the immense effort of flowering, draw up necessary nutrients and water, and, most crucially, ensure our survival through the winter to see another year.
While you seek us for fall color, the best time to plant us is actually much earlier in the year. The optimal window is in the spring after the last frost has passed, up until mid-summer. Planting us in early spring is ideal. It gives us an entire growing season to settle in. Our roots can spread deep and wide without the pressure of an impending bloom cycle. We can focus on developing strong, healthy foliage, which acts as the solar panel that fuels all our future activities. By the time the shorter days of late summer arrive, we are firmly established, well-nourished, and perfectly prepared to support a spectacular and vibrant display of flowers that will last for weeks.
If you purchase us in full bloom from a garden center in September and immediately plant us, you are asking us to perform two of the most energy-intensive tasks simultaneously: establishing roots and supporting massive flowers. We simply cannot do both effectively. The stress often causes us to droop, our blooms may fade prematurely or be less vibrant, and we enter the winter vulnerable and weak, often resulting in our demise. The intense heat and stronger sun of late summer can also scorch our leaves and desiccate us before our roots can reach deeper, cooler soil moisture. For the best show of color with pre-potted mums, we recommend keeping us in our containers, ensuring consistent water, and enjoying us as stunning annual decorations. If you do plant us in the fall, do not expect us to return in subsequent years; treat it as a bonus if we do.
