Autumn olive | The Morton Arboretum

Autumn olive is an exotic weed in Illinois. The Illinois Exotic Weed Act prohibits the sale or distribution of this plant in Illinois. This plant spreads through its numerous seeds that are typically dispersed by animals. It commonly grows in disturbed areas, and other common habitats can include woods, grasslands, or forests. The shrub is intolerant of moist environments. Autumn olive was introduced from Asia as an ornamental, as well as for erosion control. The plant has spread vigorously and today can be throughout the Eastern United States, as well as in a few western states.

Autumn olive is also an invasive plant. An invasive plant is a plant species that is non-native to the location being considered and whose presence and spread negatively impacts (or is likely to impact) ecological and economic health. Autumn olive has the ability to generate hundreds of thousands of seeds. The rapid growth rate of seedlings allows them to outcompete other nearby plants for space and sunlight. This can result in the displacement of other plants, and lead to a monoculture of autumn olive. This plant is also known to change the nutrient composition of soil and make environments favorable to its own growth, while simultaneously making the area less inhabitable for other plants (allelopathy). Data collected at The Morton Arboretum show that this tree is invasive on the Arboretum grounds.

In its place, white sage (Artemisia ludoviciana) can be planted as a good alternative. This herbaceous perennial is hardy, has a shrublike growth pattern, and has leaves with a similar silver appearance. There are a number of native and non-native species that could be used in place of autumn olive. More desirable species may be found using the online Search Trees and Plants page of the Arboretum website. Before purchasing or planting, be sure to check for any local or state guidelines on these species, and ensure that the plant is suitable for its habitat by checking its attributes at mortonarb.org or plants.usda.gov.

More Information

Size and Method of Spreading

Autumn olive is a large shrub that typically reaches 10 feet, but can grow to be up to 20 feet tall and 30 feet wide.

Bark Color and Texture

The dark gray bark begins with a smooth texture with elongated marks (lenticels). As the tree matures, the bark can peel into thin strips.

Leaf Description

The upper side of the leaves are usually light green to dark green in color with silvery undersides. The small, alternate leaves are 1 to 3 inches wide and 1 to 1 ¼ inches wide. The leaves are lanceolate with entire leaf margins.

The fragrant, yellow-white flowers are bell shaped with four petals. Abundant clusters of flowers ½ inch long appear from mid- to late spring.

Fruit Description

The dry fruit (achene) is oval shaped and covered by a fleshy layer giving it a drupe-like appearance, similar to a cherry. As the small fruit emerges, it is a pale yellow color. Through the process of maturing, it takes on a darker red color, and silver scales begin to appear on the fruit.