Flowers for the Midwest United States are in the USDA hardiness zones of 3 to 6. Flower bed plants will need to be hardy to a zone 3 in the northernmost areas and to a zone 6 in the southernmost part. Use heat-tolerant perennials, as they can withstand periods of lesser rain and high humidity. Plants for this region should not be inclusive of these zone numbers.
Shore juniper, Juniperus conferta, is from the cypress family and also known as Blue Pacifica juniper and Japanese shore juniper. It is an evergreen shrub that is drought tolerant and has fragrant grayish green or bluish green leaves in the shape of needles. The plant will get between 12 and 18 inches in height but can be 10 feet in width. Plant this one in well-drained soils and full sun. It can grow in partial shade but will not be dense coverage. Propagate by tip cuttings, and grow in USDA hardiness zones of 5 through 10.
The knockout rose, Rosa Radrazz, is an easy-to-grow shrub. It is fast growing, fragrant and tolerant of many conditions. It has red flowers in terminal clusters with foliage getting burgundy color in the fall season. The shrub will get 4 feet tall and 3 feet wide. Plant this one in full sun or partial shade in any soil or moisture. Do not propagate this cultivar, as it is under patent and propagation is illegal. It is grown in USDA hardiness zones of 4 through 9.
Powis Castle Artimisia
Powis Castle artimisia, Artemisia x Powis Castle, is from the aster/daisy family and is a perennial shrub. Mounds get 2 to 3 feet tall and twice as wide with silvery gray foliage. There is rarely a flowering one, but when they do flower, blooms are silvery yellow and in 6 inch panicles. Plant this one in full sun or partial shade with regular watering in a well-drained soil. Propagate via cuttings. It is grown in USDA hardiness zones of 6 through 8 (good for the southern Midwest only).