Chrysanthemums, commonly known as mums, are a popular symbol of autumn, providing vibrant color as other blooms fade. Many people wonder if these potted plants can be moved into the permanent garden landscape. The answer is yes, but success depends heavily on the specific variety purchased and the timing of the transplant. Understanding the different types and providing the right conditions allows the plant to establish its root system, giving it the best chance to survive colder temperatures and return as a perennial.
Understanding Mum Varieties
A chrysanthemum’s long-term survival depends on whether it is a “Garden Mum” or a “Florist Mum.” Garden mums, also called hardy mums, are perennial varieties bred for cold tolerance, typically surviving winter in USDA Hardiness Zones 5 through 9. These plants develop a robust root system and produce underground shoots (stolons), which are necessary for overwintering and returning the following year.
Florist mums are often treated as annuals and cultivated primarily for potted fall displays. While engineered to produce a dense, uniform ball of blooms, they possess a shallower root system with few or no stolons. This lack of a deep, hardy structure makes them vulnerable to freezing and thawing cycles, significantly reducing their chance of survival. Florist mums are often identifiable by their tightly packed, dome shape and high volume of flowers, suggesting greenhouse cultivation for a single seasonal display.
Successful Transplanting Steps
For perennial survival, the best time to plant a mum is in late summer or early fall, ideally six to eight weeks before the first hard frost. This timing allows the roots sufficient time to establish themselves before the ground freezes. Select a site that receives full sun, meaning at least five to six hours of direct sunlight daily.
The soil must be well-draining, as mums do not tolerate being waterlogged, which can lead to root rot. Prepare the planting hole by digging it twice as wide as the root ball and incorporating organic matter like compost to improve drainage and fertility. Gently loosen any tightly coiled or root-bound roots before planting to encourage outward growth.
Set the mum so the top of the root ball is level with or slightly below the surrounding soil surface. Do not bury the plant’s crown—the point where the stems meet the roots—too deeply, but ensure the root mass is completely covered. After backfilling, water the plant thoroughly to settle the soil and eliminate air pockets.
Ongoing Care for Established Mums
After transplanting, maintain consistent moisture, as mums require plenty of water while their root system expands. Do not allow the soil to fully dry out, especially during the first few weeks, but avoid overwatering. As flowers fade, deadheading (removing spent blooms) should be performed. This redirects the plant’s energy away from seed production and toward root development.
Once the blooming season ends and foliage is killed by the first heavy frost, prepare the plant for winter. Do not cut the plant back immediately; leaving the dead top growth provides natural insulation for the crown throughout the cold months. After the ground freezes, apply a loose, airy mulch, such as straw or pine needles, several inches deep over the planting area. This mulch prevents the soil from repeatedly freezing and thawing, which causes damaging frost heaving.
In the spring, once new growth emerges, cut the old, dead stems back to just above the soil line. To encourage a bushy habit and prevent the plant from becoming leggy, use a technique called “pinching” throughout the spring and early summer. Pinching involves removing the top half-inch of new growth on each stem every few weeks until early July. This forces the plant to branch out, resulting in a higher density of fall flowers.