Plant mums in areas that receive sun for at least half of each day. Rich, fertile soil high in organic material is best, along with good drainage. Plant them in your flower bed at the same depth that they were growing in its pot. Mums prefer constantly moist—but not soggy—soil. It is important to make sure they have enough water as they head into winter. A lot of root growth will occur, even after the tops have gone dormant. Mums don’t require fertilizer until their growing season in spring.
It can be useful to “de-bud” 50-75% of the buds—the plant will force fewer but much larger and showier blooms.
If you plan on using them as perennials, be sure to give them adequate space. They can grow and multiply rather quickly.