Some Outstanding Woody Ornamentals Native to Missouri

The idea of landscaping with native plants is becoming increasingly popular. It makes sense to use trees and shrubs in landscape designs that have evolved in our climate and have proven themselves in their native habitats. However, the fact that a plant is native does not guarantee that it will perform well in the difficult soils and microclimates often found in commercial and residential landscapes. A plant that thrives in the understory of an oak/ hickory forest may struggle to survive when planted in a clay soil with low organic matter in full sun. When considering a native tree or shrub, a little homework on its cultural requirements will help in site selection and preparation to maximize the chances of success. In some cases, it may be better to choose a different plant than to attempt to modify the site to simulate the conditions found in the natural habitat of the native.

Following is a short list of shrubs and small trees generally classified as native to Missouri which I consider to have outstanding ornamental features and to be somewhat forgiving of less than ideal site conditions. There are, of course, many other woody species that could be included on the list, but these are a few of my favorites that I consider under-utilized.

Winter Witchhazel (Hamamelis vernalis) is an outstanding, upright, multi-stemmed shrub growing to about 10 feet. It has glossy, dark green foliage turning a beautiful, clear yellow in fall. Small globose flower buds usually open in January to display reddish, strap like petals, creating winter interest. In addition to its ornamental features, H. vernalis is useful because it tolerates clay soils and partial shade well. It also tolerates high soil pH better than its native cousin, common witchhazel (H. virginiana) While it is a little large and informal for some uses, this is a great plant for use as a naturalizer on the edge of the woods.

Blackhaw (Viburnum prunifilium), a native viburnum with outstanding, season-long ornamental features is another good naturalizer. A small, thickly branched tree or large shrub, growing to 15 or 20 feet, it has glossy, serrate leaves that often have an exceptionally good red fall color. With attractive white flowers in spring and excellent, multi-colored fruit display in fall, this is a plant with something for everyone. As indicated by the fact that this species is commonly encountered in the woods over most of the state, it is adaptable to a wide range of soil conditions and tolerates a fair amount of shade. This is definitely an under-utilized plant.

Inkberry (Ilex glabra) is a broadleaf evergreen shrub useful for hedges, or massing. With thick, glossy leaves, it creates an interesting texture in the landscape. While I. glabra is native to southern Missouri, the species is too large and ungainly for most landscape situations. However, compact cultivars such as ‘Nordic’ (4 feet) and ‘Shamrock’ (3 feet) are commonly available in retail nurseries. Unlike most evergreens, inkberry can tolerate wet soils fairly well, often being found in swampy areas in the wild.

Possumhaw (Ilex decidua). Possumhaw is a deciduous holly that, although a bit wild and wooly, is worth planting for its fruit display alone. It grows to 15-20 feet, developing horizontal branches that produce multitudes of bright red fruits that persist well into the winter. Due to its size and tendency to sucker, possumhaw needs some space. It should be planted where the red berries can be viewed against the snow or with an evergreen background. It tolerates high pH soil better than its more refined cousin winterberry (Ilex verticillata) which is also considered a Missouri native by some.

Pawpaw (Asimina triloba). While pawpaw is not a plant for everyone, given the right planting site, it can create a lot of interest in the landscape. With foot-long, tropical looking leaves, lurid purple flowers and edible fruit, it stirs the imagination. As a bonus, its pure yellow fall color rivals that of Ginkgo. Pawpaw prefers a deep, moist but well drained, slightly acidic creek bottom type soil and partial shade. However, if grown in full sun, the tree has a much less gangly growth habit and better fall color than it does in the dense shade where it is often found in the wild.

Black Gum (Nyssa sylvatica) is an excellent, slow growing, medium-sized (40 feet) specimen tree with glossy, dark green leaves and a formal pyramidal form. With simultaneous fall colors on a single tree ranging from yellow to orange to purple to scarlet, black gum has arguably the best fall color of any Missouri native tree. Although it is generally considered difficult to transplant, it is increasingly common to find it in nurseries as a container grown plant. Once established, black gum is reasonably stress tolerant and grows well in wet sites if the pH is below 6.5.

American Hophornbeam (Ostrya virginiana) is an outstanding small (30 feet), oval-headed tree that performs well in urban landscapes. Its horizontal or drooping branches, serrate leaves, hop-like fruit and exfoliating bark make it interesting in all seasons. Although it is considered somewhat difficult to transplant, it is drought tolerant once established and has no serious insect or disease problems. It grows in full sun or partial shade.

American Hornbeam (Carpinus caroliniana) is another excellent and under-utilized small tree that illustrates the confusion caused by using common names. In addition to American hornbeam, it is known as blue beech, water beech, musclewood, ironwood and various other monikers, depending on where one finds oneself in the country. Being a member of the Betulaceae (birch family), it is definitely not a beech. American hornbeam is a small (20-30 feet), multi-stemmed tree often found in the forest understory, where it tolerates dense shade. The common name “musclewood” refers to the fluted appearance of the smooth, grayish bark that may remind one of rippling muscles. This is a species that might provide interest as an understory tree in a “mature” landscape with large trees. While fall color is variable, it is often an attractive yellow-orange.

It is important to note that, while many Missouri natives may be excellent, adaptable, stress tolerant ornamentals with few pest problems, they may be difficult to find in retail nurseries. To stay in business, a nursery must stock plants that people actually buy. In some cases, a native species may seem too common to be appealing to a retail customer. In other cases, the customer may simply be unaware of the outstanding features of the plant because he or she may not have seen it used in landscapes and may not recognize its name. All too often, nurseries stock native trees and shrubs like yellowwood or possumhaw only to find them in the “leftover” section at the end of the season. Hopefully, this situation will improve as more Missourians become aware of the terrific natives around them and learn how they can be used to simulate natural settings in commercial and residential landscapes.

Chris Starbuck, Woody Ornamental Horticulture, UMC (573) 882-9630