A new garden chrysanthemum with a shrub plant habit is released as a descendent of a cross involving two hexaploid species: Chrysanthemum weyrichii (Maxim.) Tzvelv. (female) × C. ×grandiflorum Tzvelv. (male). Chrysanthemum ×hybridum Anderson MN 98-89-7 [U.S. Plant Patent (PP) 14,495] is a vigorously growing shrub chrysanthemum for garden culture, exhibiting extreme hybrid vigor. Single daisy reddish-purple flowers cover the foliage in the fall, numbering >3000 on second-year plants. This selection displays excellent winterhardiness in U.S. Department of Agriculture (USDA) Z3b+ (–34.4 to –37.2 °C) as well as frost-tolerant flowers. In its second and subsequent years of growth after planting, MN 98-89-7 grows into a fall flowering (August–October), herbaceous shrub ranging in plant height from 61.0 to 91.4 cm with a diameter of 76.2 to 152.4 cm. Its spherical plant shape is achieved naturally with self-pinching, creating a highly manicured appearance; it also attracts honey bees and butterflies as pollinators. MN 98-89-7 is a vegetative product and this unnamed selection is being released for germplasm purposes as well as for potential licensing and naming.