At The Garden Corner, we choose to treat chrysanthemums as a fall annual, adding a burst of color to primarily evergreen baskets and container planters. Technically a perennial, you might consider planting hardy mums in the ground where it will get all-day sun in the spring and summer, or a minimum of six hours of sun a day. This encourages loads of blooms and healthy upright plants that can grow anywhere from 12 to 36 inches tall and about as wide. Any springtime buds that appear can be pinched out to increase the density of blooms in late summer/fall. Mulching the plants heavily as the temps dip also ensures good blooms the following year.