Weed of the Month | Autumn Olive (Elaeagnus umbellata)

In the 1950’s the U. S. government recommended this East Asian native for a number of projects including strip mine reclamation, erosion control, windbreaks, highway plantings, plantings for wildlife and ornamental landscaping. Autumn olive has many desirable features including attractive leaves, fragrant flowers, showy red fruits edible by humans and wildlife and the abilities to fix nitrogen in the soil and grow just about anywhere. However, this large thorny shrub can also send out suckering roots to form vast thickets and can bloom and fruit at a young age and spread its numerous seeds far and wide. Birds and other wildlife find the fruits irresistible, and many humans find them tasty and nutritious, too. Because autumn olive is such an aggressive colonizer, it easily outcompetes and displaces native vegetation, prompting many states in the eastern U. S., including New York, to ban its sale, distribution or cultivation. Prairies, meadows and open woodlands are native habitats especially endangered by this invasive.

Multi-stemmed and a rapid grower, autumn olive can be up to 20 feet tall and 20 feet or more wide. Thorny branches arch to the ground and create a dense canopy under which very little else grows. Leaves are elliptical, dark above and silvery beneath. Silvery white or dull yellow flowers appear in drooping clusters in early spring and are followed by the desirable, sweet-tart fruits in late summer.

Autumn olive is now naturalized across much of the eastern half of the U. S., from Zones 4-9. Often found in disturbed areas, it is also common along roadsides, fence rows and woodland edges and in meadows and abandoned fields.

Control of autumn olive once it has taken hold of a landscape is difficult, if not impossible. Young plants can by pulled and slightly older plants can dug by hand. It’s important to pull or dig all the roots.

For large plants and established stands, most government agencies recommend cutting stems at the base and painting or spraying exposed cuts with herbicide. Without herbicides, plants need to be dug with large equipment, a costly and damaging operation that may require habitat or landscape restoration when completed.

At Bridge Gardens, during some recent work in the woodland garden, we found and promptly removed several relatively young autumn olives and will do so again if we find any more. As with any weed, monitoring regularly and removing the problem before it gets too big are the best means of control.