AMES — Fall in Iowa is often one of the best times, with warm days and cool nights, low humidity and the brilliant autumn colors of the trees. Horticulturists with Iowa State University Extension and Outreach share information about adding trees with colorful fall foliage to home landscapes. Homeowners with additional questions should contact ISU Hortline at 515-294-3108 or firstname.lastname@example.org.
Which shade trees have colorful fall foliage?
Shade trees that possess excellent fall foliage include Freeman maple (Acer x freemanii), red maple (Acer rubrum), sugar maple (Acer saccharum), black maple (Acer nigrum), white oak (Quercus alba), red oak (Quercus rubra) and black gum (Nyssa sylvatica). Freeman maples are hybrids of red and silver maples. Their leaves vary from orange to red in fall. Popular Freeman maples include Autumn Blaze, Sienna Glen and Firefall. The red maple cultivars Red Sunset, Redpointe, and Scarlet Jewell have dark red foliage in fall. Sugar maples are native to eastern Iowa. Their fall foliage varies from yellow to orange to reddish orange. ‘Commemoration,’ ‘Legacy’ and Fall Fiesta are excellent sugar maple cultivars. The fall foliage of black maples varies from yellow to orange. In fall, the foliage of white oaks is often reddish brown, while red oaks have wine red foliage. Black gums are not widely grown in Iowa. They are somewhat difficult to transplant and prefer moist, well-drained, acidic soils (pH 6.0 to 6.5).
However, the black gum possesses outstanding fall foliage. Its foliage is often bright red in fall.
Additional trees include yellowwood (Cladrastis kentukea) with yellow fall foliage, ginkgo (Ginkgo biloba) cultivars ‘Autumn Gold’ and Presidential Gold with golden yellow fall color, honeylocust (Gleditsia triacanthos var. inermis) with yellow fall color, ‘Moraine’ sweet gum (Liquidambar styraciflua ‘Moraine’) with foliage that varies from yellow to red to purple, and Dutch elm disease resistant American elms (Ulmus americana), such as ‘Jefferson,’ ‘Princeton,’ and ‘Valley Forge,’ with yellow fall foliage.
Which small trees have colorful foliage in fall?
Small-stature trees (those less than 30 feet in height) that possess good fall foliage include serviceberry (Amelanchier spp.), American hornbeam (Carpinus caroliniana), and redbud (Cercis canadensis). Serviceberries, such as ‘Autumn Brilliance,’ turn yellow to orange to red in fall. The American hornbeam cultivars Firespire and ‘J.N. Strain’ have red-orange fall color. The heart-shaped leaves of redbud turn yellow-green to clear yellow in fall.
Which shrubs have good fall color?
Several deciduous shrubs have colorful fall foliage. The fall foliage of fothergilla (Fothergilla spp.) varies from yellow to orange to red. Common witchhazel (Hamamelis virginiana) has yellow leaves in fall. In autumn, the foliage of Virginia sweetspire (Itea virginica) varies from yellow to orange to reddish purple. Spicebush (Lindera benzoin), staghorn sumac (Rhus typhina), and blackhaw viburnum (Viburnum prunifolium) have yellow, red and reddish purple foliage respectively.
Why does fall leaf color on trees and shrubs vary from year to year?
The weather in early fall largely determines the intensity and duration of leaf color in those tree and shrub species capable of producing good fall color. Best fall color typically develops when days in early fall are sunny and mild and nights are cool (but remain above freezing). Long periods of cloudy, rainy weather or a hard freeze in early fall will mute fall colors.