The Garden Bug: Hardy Mums
By Brenda Weaver
Unlike "florist mums" that are grown only for fall flowering and treated as annuals, "hardy mums" are cold-hardy garden perennials. These plants grow best in rich soil with a slightly acidic to neutral soil pH (6.2 to 7.0).
Good drainage is needed to avoid root rot. Hardy mums are photoperiodic, meaning they bloom in response to shorter days and longer nights, so don't plant them near street lights; artificial lighting wreaks havoc with their flowering.
Source: www.thespruce.com