With the arrival of spring, many people across the state are eyeing their local nurseries, greenhouses and garden centers for trees and shrubs to plant to spruce up their property. However, the process of selecting a species can be overwhelming, with dozens of choices at greenhouses and exponentially more available through mail-order catalogs. With infestations of Emerald Ash Borer in the state, it is logical to avoid planting the various ash species. Maples constitute a staggering percentage of urban trees, averaging approximately 34% according to the Iowa Department of Natural Resources, and should be avoided to promote diversity within the landscape. So what should you plant, if not ash or maple?
When selecting a species to plant in your landscape, evaluate the particular site conditions and any height or size restrictions. Consider the desired benefits of the tree, are you looking for a phenomenal wildlife species, or one that offers a unique appearance throughout the year? Next, look around your neighborhood and try to plant a species that is not represented in your local landscape. The following species are outside of the ash and maple families, well suited to the harsh urban climate and would make great additions to any landscaping project. This is by no means a comprehensive listing, simply a few unique species to consider for your site. Photos and additional information from ISU Forestry Extension are available at the links under the tree names.
Large shade trees for open spaces with no overhead clearance restrictions:
- Shingle Oak (Quercus imbricaria) will grow from 50-75' tall and 40-70' wide. This tree does not have the characteristic oak shaped leaves, featuring narrow, oblong, smooth leaves instead. Shingle oak is low maintenance with good resistance to pests and diseases. The fall color varies from reddish to yellow-brown. This species can show iron deficiency symptoms if planted on high pH soils but can adapt well to most other conditions. An Iowa native.
- Kentucky Coffeetree (Gymnocladus dioicus) grows to 60-75' tall and 40-50' wide. A native tree to Iowa that is highly adaptable to different soil and climate conditions. Produces seedpods similar to an Eastern Redbud but slightly larger. A hardy tree perfect for urban sites. Offers uniquely large leaves consisting of up to 40 smaller leaflets.
- Ginkgo (Ginkgo biloba) var. 'Autumn Gold' or 'Presidential Gold' will grow 50-80' tall and 25-35' wide. Distinct and interesting fan-shaped, bright green leaves. Highly adaptable to different soil and climate conditions. Perfect for use as a street tree, tolerating small spaces and salt sprays. The two varieties listed have foliage that will turn a brilliant gold color in the fall.
- Bald Cypress (Taxodium distichum) is a deciduous conifer, which means it has needles like other conifers but loses those needles each year. It will grow 50-70' tall and 20-30' wide. Adaptable to wet and dry soils and is well suited for urban conditions. A beneficial wildlife tree used by many different species.
- European Larch (Larix decidua) is another deciduous conifer, growing 70-75' tall and 25-30' wide. It is adaptable to different soil conditions and tolerant of Iowa's urban climates. This tree can add a unique appearance to your landscape with beautiful fall color, turning a golden yellow.
Low growing trees for locations with height restrictions, typically under 30' tall:
- Eastern Redbud (Cercis canadensis) grows 20-30' tall and 25-35- wide. Beautiful pink flowers in the spring and heart shaped foliage, which turns yellow-gold in the fall. Produces a seedpod similar to a pea pod that will remain on the tree throughout the winter months. An Iowa native.
- Common Chokecherry (Prunus virginiana) grows 20-30' tall and 15-25' wide, and is an Iowa native. Adaptable to different conditions and can tolerate heavy pruning year to year. Produces small, delicate white flowers in the spring and nearly black berries. Once ripe, the berries are edible to humans and loved by wildlife.
- Hawthorn (Crataegus sp) has varying height and width growth depending on your chosen cultivar. Prefers moist, well-drained soils but can adapt to other conditions. Uniquely shaped foliage with light pink spring flowers. Dark red to orange berries in clusters used by many different wildlife species. An Iowa native.
- Japanese Tree Lilac (Syringa reticulata) grows 20-30' tall and 15-25' wide. This tree provides the beauty and enticing aroma of the lilac bush but in a more upright and manageable form. It prefers moist, well-drained soils, however, it is tolerant of other soil conditions. Quite tolerant of salt spray and enjoyed by wildlife species.