The autumn olive, Elaegnus umbellata, is a common deciduous shrub widely established across the United States. It is recognized by its distinctive silvery leaves and the abundance of small, speckled red fruit it produces in the autumn. This large, multi-stemmed plant often grows 10 to 16 feet tall. Its widespread presence makes it a familiar sight in disturbed areas, along roadsides, and in open fields.
Botanical Identity and Characteristics
Elaegnus umbellata is classified as a large deciduous shrub or a small, sprawling tree belonging to the Oleaster family. It typically reaches 10 to 20 feet in height with a spread of 20 to 30 feet, forming a dense, bushy crown. The bark on older trunks is gray and may appear split or furrowed, while younger branches are covered in small, silvery-brown scales.
The leaves are arranged alternately along the stems and are typically elliptic-oblong, growing up to three inches long. The top surface is dull green, while the undersides are a striking whitish-green, densely covered with tiny, silvery-white scales. These leaves emerge early in the spring, often before many native plants, giving the shrub a competitive advantage.
In late spring to early summer, the plant produces small, fragrant flowers that hang in clusters from the leaf axils. These flowers are tubular, pale yellowish-white, and have four lobes, emitting a sweet, strong scent that attracts pollinators. Following the bloom, the plant develops small, round, fleshy fruits (technically drupes) about one-third of an inch in diameter. These fruits mature in the autumn, changing to a speckled bright red, which is the source of the plant’s common name.
Geographic Spread and Ecological Impact
The autumn olive is native to East Asia, spanning from the Himalayas to Japan and Korea. It was first introduced to the United States in the 1830s as an ornamental shrub. Widespread establishment in North America began in the mid-20th century when it was actively promoted by the U.S. Soil Conservation Service.
It was planted extensively for windbreaks, highway beautification, erosion control on strip-mined lands, and as a source of food and cover for wildlife. These efforts quickly demonstrated the plant’s aggressive nature, leading to its rapid naturalization across most of the central and eastern U.S. The plant’s success is due to its remarkable tolerance for poor conditions, including drought, salt, and nutrient-deficient soils.
The primary mechanism making the autumn olive invasive is its ability to fix atmospheric nitrogen. Like legumes, it forms root nodules in symbiosis with specialized bacteria, allowing it to thrive and enrich soils low in nitrogen. This biogeochemical change favors the autumn olive and other weedy species, enabling it to out-compete and displace native plants adapted to infertile conditions.
The shrub is also a prolific seed producer, with a single mature plant capable of generating up to 200,000 seeds annually. The bright red, palatable berries are readily consumed by birds and mammals, which distribute the seeds widely across landscapes. Once established, the fast-growing shrubs form dense, monoculture thickets that shade out and suppress the growth of native species, severely reducing local biodiversity.
Culinary Use and Nutritional Profile
The fruit of the autumn olive is fully edible and has a distinctive sweet-tart flavor profile. The berries are astringent if harvested before they are fully ripe, but they develop a juicy, pleasantly acidic taste once they mature in the fall. They are commonly used to make jams, jellies, sauces, and fruit leather, often serving as a substitute for other tart fruits.
The fruit is notable for its exceptional nutritional content, particularly its high concentration of the antioxidant lycopene. Lycopene levels in the red berries typically range from 15 to 54 milligrams per 100 grams of fresh fruit. This concentration is substantially higher than the lycopene content found in fresh tomatoes, traditionally considered a major dietary source of this carotenoid.
In addition to lycopene, the fruit contains other beneficial carotenoids, such as beta-carotene and lutein, and is a good source of Vitamin C. The high antioxidant content has led to increased interest in its potential health benefits, especially in supporting cardiovascular health. Consuming the berries with a source of fat can enhance the absorption and bioavailability of the lycopene.