A potted mum will bloom indoors for approximately four weeks when kept slightly moist to on the dry side. But once the blooms have faded you can rebloom them next fall, however, most indoor conditions will not be sufficient if you wish to rebloom the plant. Move the mum outdoors after any danger of frost. Place mums in an area where they receive at least six hours of sunlight. Continue watering and fertilizing the plants through summer. Potted mums cannot tolerate a frost, so bring them indoors in fall before the first frost occurs. Typically, a mum will bloom again in late October or November.