Utah State University Extension
This fact sheet describes plants that can give landscapes color all season long with blooms in spring, summer, fall and winter interests. It includes a listing of trees, shrubs, perennials, vines, ground covers, bulbs, and ornamental grasses.
Gunnell, Jaydee; Hansen, Sheriden; Greenhalgh, Linden; and Christley, Holly, "Landscaping for Season Long Color" (2019). All Current Publications. Paper 1933.