How to Identify Autumn Olive

Autumn olive grows as a large shrub in open areas and along forest edges. It has light green leaves that are silvery underneath. Small fragrant clusters of pale yellow flowers bloom in spring. The fruits mature in late summer turning bright red with silver dots. The fruits are edible and are high in lycopene, the same anti-oxidant found in tomatoes.

Photo courtesy of Pennsylvania Department of Conservation and Natural Resources - Forestry Archive, Bugwood.org

Being a Nitrogen-Fixer Is Not Always Helpful

Autumn olive can also change soil nutrient conditions because bacteria associated with its roots turn nitrogen from the atmosphere into organic nitrogen in the soil. Often we think of more nutrient-rich soils as being a benefit, but many native plant species are adapted to low-nutrient soils and invasive exotic species out-compete them in enriched soils.

Photo courtesy of Chris Evans, River to River CWMA, Bugwood.org

How to Control Unwanted Autumn Olive Shrubs

Seedlings of autumn olive can be hand-pulled, particularly in moist soils. For large shrubs, cut the trunk as close to the ground as you can. Within 2 minutes of cutting, drive 4 or 5 holes into the stump and pour concentrated herbicide containing glyphosate, such as Roundup® Weed & Grass Killer Concentrate Plus, into the holes. This treatment is most effective in late summer when the shrubs are beginning to move carbohydrates back down into the roots for winter storage. Shrubs can also be sprayed with a product like Roundup® Ready-to-Use Poison Ivy Plus Tough Brush Killer, following the instructions on the label.

Autumn Olive's Relatives

Closely related to autumn olive is Russian olive, a small tree with dry yellow fruits. Russian olive (shown) is seldom planted in the eastern U.S. but is a problem plant in the western U.S.. Farmers grow sea buckthorn shrubs, a thorny relative of autumn olive, commercially in Canada for the vitamin-rich fruits, and it is promoted as an ornamental shrub in coastal communities. It has become invasive in Canadian prairies along floodplains.

Great Alternatives to Autumn Olive

You can choose among many great shrubs to replace autumn olive. Bayberry (shown in photo) and southern wax myrtle will have about the same height and shape as autumn olive. Nannyberry viburnum has glossy leaves and colorful fruits that birds love and that people can eat too. Maple leaf viburnum, also called highbush cranberry, has bright red, edible fruits.

»  Find out about another problem shrub, multifora rose