Overview

The Autumn olive (Elaeagnus umbellata) is an invasive, deciduous shrub or small tree. This densely branched plant can grow up to 20 feet and up to 30

feet wide. (Figure 1). The twigs have tiny scales, which also appear on the fruit, and undersides

of leaves. The Autumn olive is a fast grower and prolific seed producer. While roots are capable of fixing nitrogen in the soil, Autumn olive out-competes and displaces native shrubs.

Autumn olive, native to China, Japan, and Korea, is found in the U.S. from Maine, south to northern Florida, west to Nebraska, with scattered infestations in the Northwest U.S. It was introduced into the U.S. in the 1830s, for erosion control and as a windbreak, and for its showy foliage, flowers and berries.

Russian olive (Elaeagnus angustifolia) is similar in appearance and also invasive in Connecticut, but less common. The Russian olive can be distinguished from Autumn olive by its leaves, which have silvery scales on both sides, and its mealy, yellow or silvery fruit.

Other characteristics of Elaeagnus umbellata include:

• LEAVES: Alternate, oval, simple, leathery, 2-4 in long, with finely pointed tips and short petioles. Green tops of leaves, with silvery scales on the lower surface. Margins are often wavy and lack teeth. Leaves emerge early, in mid- March.
• BARK/STEMS: Young stems and buds are silvery-gray with brownish scales (lenticels), producing a speckled appearance. One to three inch sharp thorns are formed on branch spurs. Mature bark is light gray to gray-brown, commonly furrowed, with prominent lenticels (intercellular spaces appearing at the bark level).
• FLOWERS: Small, yellowish-white, tubular (fused at the base), with four petals, which are pointed at the tips; arranged in clusters of one to eight flowers which are prolific from April to June, with peak bloom in mid-May. Highly fragrant, with a lily-like scent. Pollinated by insects.
• FRUIT: Fleshy, round, abundant clusters of drupes from August to October. Emerge silvery with brown scales; mature to bright red, finely dotted with metallic scales, with a rough, sandpapery feel.
• REPRODUCTION/SPREAD: Predominately by seed, which is eaten and dispersed by birds and mammals. Some vegetative propagation also occurs. Open-pollinated, often by insects.

Autumn olive out-competes and displaces native shrubs, forming monotypic stands that reduce habitat diversity. An aggressive invader of roadsides, pastures, old fields, and other disturbed habitats that spreads rapidly. It thrives in full sun and a variety of soil and moisture conditions; it is moderately shade tolerant. It is extremely hardy and tolerates drought, wind, and air pollutants. As a nitrogen fixer, it can interfere with natural plant succession and nutrient cycling, and can change soil suitability for other shrub species.

Control

For best results, undertaking a combination of control tactics to manage this plant is recommended. Refer to CIPWG’s Management Calendar (cipwg.uconn.edu) for more information.

Mechanical Control may be sufficient to eradicate small infestations. For established stands, mechanical controls may be used in conjunction with chemical controls for more effective results. Any Autumn olive plants found to be newly colonizing an area should be removed as soon possible, by pulling or digging to remove seedlings and small plants. Tools such as the Extractigator® or Root Talon© can help facilitate removal of larger plants. Root crowns must be entirely removed in order to prevent resprouting. Hand removal of specimens larger than 3.5 in. in diameter is not recommended, due to the likelihood of resprouting from any roots that remain in the soil. Removal is easiest when the soil is moist. Minimize soil disturbance and tamp down soil after completion. Wear thick gloves and/or long canvas sleeves for protection from the plant’s thorns.

Repeated cutting or mowing this plant will limit autumn olive’s spread, but resprouting will occur from the root crown. Resprouts can be treated with herbicide for greater efficacy. Girdling of the tree trunk may be an effective method to reduce vigor or kill large trees. A cut through the bark, approximately six inches above the ground, and a cut completely around the trunk, will kill the top of the tree. However, resprouts are common, and several years of follow-up treatments may be required.

When considering chemical treatment, follow label directions.

Foliar sprays (e.g.,triclopyr) are effective from one month after leaf expansion until mid-autumn.

Cut-stem treatments: Immediately after cutting, apply a systemic herbicide (e.g., triclopyr) to freshly cut stems or stumps with a paint brush or sponge applicator. Treatment can be applied anytime during the year when the plant is actively growing, except in early spring, when plant sap is flowing upwards from roots to sprouts/stems.

Basal bark treatments: A concentrated mixture of herbicide in basal oil is applied to the entire circumference of the lower 12-18 in. of the intact stem, anytime during the year.

For larger trees, three approaches are possible:

• Girdle the tree (see description above), and apply triclopyr* in the cut around the trunk;
• Cut down tree and apply triclopyr* into the freshly cut surfaces of the stump; or
• Cut down tree and spray re-sprouts before they get too tall to correctly spray the top surface.

Autumn olive plants treated with any herbicide should be monitored for several years, as they may resprout.

*Refer to Michigan Dept. of Natural Resources for more details. Penn State Extension provides more information and a management calendar.

Native Alternatives

This plant’s prolific production of berries was once considered a good source of food for wildlife. The fruit has been found to be low in nutritional value in comparison to the native shrub species they displace.

Recommended native alternatives:

For persistent berries and bright fall color:

• Aronia arbutifolia (red chokeberry)
• A. melanocarpa (black chokeberry)

For persistent berries:

• Ilex verticillata (winterberry)
• Viburnum opulus ssp. americanum (syn. V. trilobum)
• Highbush cranberry (NOT the European V. opulus ssp. opulus)

For fall wildlife food source:

• Cornus amomum (silky dogwood)
• C. racemosa (gray dogwood)
• C. sericea (red twig dogwood)

Additional Resources

Chandran, R. & Loyd, B. (n.d.). Autumn Olive. West Virginia University Extension. https://extension.wvu.edu/lawn-gardening-pests/weeds/autumn-olive

Maine Natural Areas Program. (n.d.) Maine Invasive Plants Bulletin #2525: Autumn Olive/Russian Olive. University of Maine Cooperative Extension. https://extension.umaine.edu/publications/wp-content/uploads/sites/52/2015/04/2525.pdf

Michigan Department of Natural Resources. (2012, February). Invasive Species - Best Control
Practices: Autumn olive. https://mnfi.anr.msu.edu/invasive-species/AutumnOliveBCP.pdf

National Park Service & U.S. Fish and Wildlife Service. (2010). Autumn Olive. In Plant Invaders of Mid-Atlantic Natural Areas, 4th ed. https://www.invasive.org/alien/pubs/midatlantic/elum.htm

Picone, P. (2000). Invasive Plant Information Sheet: Autumn Olive. Connecticut Invasive Plant
Working Group. https://cipwg.uconn.edu/wp-content/uploads/sites/244/2013/10/final-Autumn-Olive-factsheet.pdf

Templeton, S. Gover, A., Jackson, D., & Wurzbacher, S. (Updated 2021, October 27). Autumn Olive. PennState Extension. https://extension.psu.edu/autumn-olive

Varricchio, E. & Connecticut Invasive Plant Working Group. (n.d.). Connecticut’s Invasive Plant
Management Calendar: The Top 10 Invasive Plants [PowerPoint slides]. Connecticut Invasive Plant Working Group. https://cipwg.uconn.edu/wp-content/uploads/sites/244/2018/10/Invasive-Plant-Management-Calendar.pdf

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