The shrub known as Autumn Olive (Elaeagnus umbellata) is a tenacious non-native invasive species affecting landscapes across North America. Introduced from Asia in the 1800s, it was widely planted in the mid-20th century for erosion control and wildlife habitat. However, this plant has proven highly aggressive. Its rapid spread displaces native plant communities in forests, fields, and along roadsides. Landowners must actively manage this species because its unchecked growth alters natural ecosystems, impacting biodiversity and soil chemistry.
Recognizing the Plant and Its Invasive Nature
Identifying Autumn Olive is the first step in effective removal. The leaves are grayish-green on top, but a dense layer of silvery or brown scales on the underside gives the foliage a characteristic shimmery appearance. In spring, the shrub produces clusters of small, fragrant, creamy yellow flowers. These are followed by small, round fruits that ripen to a speckled red or pink in late summer and fall.
The plant’s success as an invader is due to two primary biological traits. Primary, it is a non-leguminous nitrogen-fixer, meaning it takes nitrogen from the air and deposits it into the soil. This allows it to thrive in poor or degraded sites where native plants struggle. This ability shifts the soil chemistry, favoring its own growth while suppressing other species. Another element is its prolific seed production: a single mature shrub can produce up to eight pounds of fruit annually, each containing a single viable seed. Birds and mammals readily consume these seeds, dispersing them widely and establishing new infestations far from the parent plant.
Manual and Mechanical Eradication Methods
For very young infestations or small seedlings, manual removal is an effective control method. Hand-pulling is most successful in early spring when the soil is moist, ensuring the entire root system is extracted. If the root crown is not completely removed, the plant will vigorously resprout.
For larger, established shrubs, mechanical removal is often necessary but requires caution. Simply cutting the trunk or repeatedly mowing stimulates prolific growth of new shoots from the root crown. This results in a denser, multi-stemmed plant that is more difficult to manage later.
To successfully use mechanical methods on large shrubs, the goal is to remove the root mass or prepare the stump for chemical treatment. Specialized equipment, like a stump grinder or a heavy-duty winch, can pull out the entire root crown and minimize resprouting. If only cutting is possible, it should be the first step in a two-part process, clearing the way for a targeted herbicide application to the remaining stump.
Targeted Chemical Control Strategies
For medium to large Autumn Olive shrubs, chemical control using systemic herbicides is the most reliable way to achieve complete eradication of the root system. Systemic herbicides, such as glyphosate or triclopyr, are absorbed by the plant and translocated to the roots, ensuring the entire organism is killed. The most effective approach is the cut-stump treatment, which concentrates the herbicide directly where it is needed.
This technique involves cutting the trunk level with the ground and immediately applying a concentrated herbicide solution to the fresh cut surface. This application specifically targets the outer ring of living tissue known as the cambium layer. Applying a 20% to 50% concentration of glyphosate or a 20% triclopyr ester mixed with basal oil is recommended. The application must occur within minutes of cutting, before the plant forms a protective seal. The late growing season (July through September) or the dormant season are the optimal times for cut-stump treatment because the plant is actively moving resources down to the roots.
Another effective method for smaller, intact shrubs (six inches in diameter or less) is the basal bark treatment. This involves applying an oil-soluble triclopyr ester solution, usually at a 20% to 30% concentration mixed with basal oil, directly to the bark. The solution should thoroughly wet the entire circumference of the lower 12 to 18 inches of the stem, avoiding excessive runoff. Basal bark applications can be performed year-round, except when the bark is wet or the ground is frozen.
Foliar spraying, where a diluted herbicide solution is sprayed directly onto the leaves, is reserved for young seedlings or widespread resprouts less than six feet tall. A solution of 2% glyphosate or triclopyr in water is used, and a surfactant may be added to ensure the chemical adheres to the waxy leaves. Due to the risk of drift, foliar applications should be used cautiously to avoid damaging desirable native plants nearby. Always wear appropriate Personal Protective Equipment (PPE) and strictly follow the herbicide product label for application rates and safety instructions.
Preventing Recurrence and Site Restoration
Achieving long-term control requires a dedicated follow-up strategy beyond the initial removal of mature shrubs. The most persistent challenge is the seed bank, as seeds remain viable in the soil for several years, leading to continuous germination. Monitoring the treated area for at least three to five years is necessary to catch and remove new sprouts before they mature and produce more seeds.
Any cut material containing fruit must be disposed of properly, as the berries can continue to ripen and disperse seeds even after the branch is severed. Chipping the material or burning it in compliance with local regulations are viable options to prevent further spread.
The final phase of eradication involves actively restoring the site with robust native vegetation. Autumn Olive thrives in disturbed, open areas, so establishing a competitive canopy and ground cover is crucial to suppress future seedling growth. Planting native trees, shrubs, and grasses adapted to the site’s conditions will help shade out new Autumn Olive seedlings and prevent the re-establishment of this invasive species.