Iowa has two USDA Hardiness zones--4 and 5--where the winter temperatures get as low as -30 and -20 F. degrees respectively. Perennial flowers for Iowa are tough, cold-hardy plants that survive the winters on the open prairies and come back the next spring. Gardeners in Iowa choose from these plants and create gardens with flowers that have grown wild in the state for centuries.
The Canadian anemone (Anemone canadensis L.) is also known as round-leaf thimbleweed, Canada anemone, windflower and meadow anemone, and is a member of the buttercup family. Deeply lobed leaves grow at the base of the plant, while a circular cluster of leaves grows on a stem 1 to 2 feet tall. A single flower with white petals and a golden center blooms from the middle of the cluster in April, May and June. Plant Canadian anemone in full or partial shade and a moist soil.
False aster (Boltonia asteroides) grows from 5 to 6 feet tall and 2 to 4 feet wide. Lance-shaped, gray-green leaves grow up to 5 feet long. Flowers with white, pink, lilac or purple petals and yellow centers measure 3/4-inch across grow in clusters in August and September. Plant false aster in full sun and a moist, well-drained soil.
Virgin's bower (Clematis virginiana L.) is a member of the buttercup family. The plant is a vine that grows from 12 to 15 feet long with clusters of small, white flowers that bloom in July, August and September and bright-green leaves. The female flowers produce feathery tails that contain the seeds in late summer. Plant virgin's bower in full sun, partial shade or full shade and a soil that is moist to dry. Hummingbirds and bees will come by for their share of the nectar.
Illinois bundleflower (Desmanthus illinoensis) is also known as bundleflower, prairie bundle flower, prickleweed and Illinois desmanthus, and is a member of the pea family. The plant grows from 1 to 5 feet all with feathery, fern-like compound leaves with six to 15 small stems, each one with 20 to 30 leaflets. Green or white flowers grow in small bell-shaped clusters on their own stems from May through September. Illinois bundleflower need full sun and a moist soil and are a favorite of buttleflies.
White Dog's Tooth Violet
White dog's tooth violet (Erythronium albidum) is also known as trout lily. The plant grows up to 1 foot tall with single, bell or lily-shaped, white flowers accented with yellow markings that bloom in April. Each flower stalk has two tongue-shaped leaves at the base. Plant white dog's tooth violet in partial to full shade and a soil that is organic and moist.