Autumn Olive

Most Virginia gardeners are familiar with the highly-invasive autumn olive (Elaeagnus umbellata), a fast-growing deciduous shrub that can get quite large —  up to 20 feet tall and 30 feet wide. It is native to eastern Asia and was introduced to the United States in 1830.  Unfortunately, autumn olive was planted for erosion control, mine reclamation — and even landscaping — beginning in the 1950’s.  Eventually, its ability to form a shrub layer so dense that it displaces native plants and overtakes open woodlands, old agricultural fields, forest edges, and roadsides became abundantly clear.  How does it do this?  Autumn olive has a number of traits that give it major advantages over other plants:  (1) it produces a large seed bank which is spread by the birds who eat its berries, (2) it is highly tolerant of salinity, extreme pH, and heavy metals, (3) it has the ability “to create its own absorbable form of nitrogen, altering the local nitrogen cycle to which native plant communities are adapted.” Penn State Extension/Autumn Olive.

Autumn olive is now recognized as invasive in much of North America (but it’s apparently not a problem in the arid West). Autumn olive is identified as an invasive species by the Va. Cooperative Extension, and is labeled as highly invasive by the Virginia Dept. of Conservation and Recreation.  A plant acquires the “highly invasive” label when it spreads easily, alters ecosystem processes, and can cause substantial impacts on undisturbed natural plant communities. Virginia is far from alone in this regard; a number of states, including Tennessee and Kentucky treat autumn olive as a “severe threat” — due to its ability to spread easily and displace native vegetation. It is identified as an invasive by most states in the eastern half of the U.S. as well as by numerous national organizations, including the USDA’s National Invasive Species list.

As it spreads, autumn olive creates a shrub layer so dense that it prevents the growth of other plants. The fact that it can transform large areas into a monoculture is a major concern.   Autumn olive has been busily transforming a large field between my family’s back yard and the forested area that borders our property.  Our field is Exhibit A on the impact of autumn olive; no dogwoods, redbuds or other desirable plants have been able to worm their way into the bulwark of autumn olives in our field. I now spend a goodly (badly?) portion of my time fighting it.  

Recently, I’ve noticed a few new sprouts growing from a dead plant I thought I had already eradicated.  I began to wonder if I was applying the “cut-stump” method correctly.  Soon it occurred to me that expert guidance on this subject might be welcomed not only by me, but by the many others dealing with this shrub.  I contacted the Blue Ridge PRISM and was delighted that one of their expert trainers — Tim Maywalt —  was willing to demonstrate exactly how to deal with autumn olive.  And we are all doubly fortunate that Tim’s demonstration was turned into an educational video by Angela Orebaugh, a fellow Master Gardener who is also an expert videographer.  The video — Controlling Invasives:  Autumn Olive — is attached here and also below.   I believe it will be helpful to all who are fighting this invasive. 

This video provides comprehensive guidance on how to control autumn olive, showing you exactly how to proceed with each method available, from mechanical to “cut-stump” to “basal bark” and everything in between.  You’ll also appreciate Tim’s discussion of the advantages and disadvantages of the various approaches, which can help you make the best possible choice.  It is well worth your time.

By the way, if you have had any dealings with the thicket-forming autumn olive, you’ll probably be as gobsmacked as I was to discover that some recent research suggests that autumn olive may have some healing medical properties.  See “Prospects for the use of Physiologically Active Compounds of umbellata,” International Journal of Life Sciences, http://www.crdeepjournal.org/wp-content/uploads/2021/06/Vol-10-3-1-IJLS.pdf (2021).  I discovered another surprising article about autumn olive titled Elaeagnus umbellata: A miraculous shrub with potent health-promoting benefits from Northwest Himalaya. I’m not making this up.  The articles I looked at mostly come from countries where autumn olive is a native and apparently NOT invasive.  We in North America must remain vigilant in restraining autumn olive,  These articles did give me cause to wonder  if autumn olive might have some saving grace after all — at least in areas where it is not invasive. But if autumn olive is to be grown for medical use, it will need to be carefully contained — especially if it’s anywhere near North America — or my backyard!

SOURCES:

With deep gratitude to Tim Maywalt of Blue Ridge PRISM (Blue Ridge Partnership for Regional Invasive Species Management, Virginia’s first Cooperative Weed Management Area and to Angela Orebaugh, Piedmont Master Gardener and UVA professor.

Controlling Invasives: Autumn Olive, a video jointly developed by Piedmont Master Gardeners, Blue Ridge PRISM, and Charlottesville Area Tree Stewards

“Autumn Olive:  Aggressive and Persistent,”  Blue Ridge Prism Fact Sheets.

“Invasive Exotic Plant Species: Autumn Olive (Elaeagnus umbellata),” Va.Coop.Ext.Publication No.420-321

“Autumn Olive,” Invasive.Org Center for Invasive Species and Ecosystem Health, University of Georgia, Invasive.org

Distribution Map, Autumn Olive in the United States, www.eddmaps.org, Center for Invasive Species
and Ecosystem Health, University of Georgia

“Watershed Vulnerability to Invasive N2–Fixing Autumn Olive and Consequences for Stream Nitrogen Concentrations,”  Journal of Environmental Quality, onlinelibrary.wiley.com (2019) (“Results from this study demonstrate how encroachment of autumn olive can influence water quality and transform biogeochemical cycles in natural systems, which points to the need for effective management of autumn olive in the edge watersheds and riparian zones that are vulnerable to invasion and increased N export.”)

“Rangelands in a fragmented grass-dominated landscape are vulnerable to tree invasion from roadsides,” Biological Invasions, springer.com   (2022)

“Prospects for the use of Physiologically Active Compounds of umbellata,”  International Journal of Life Sciences, http://www.crdeepjournal.org/wp-content/uploads/2021/06/Vol-10-3-1-IJLS.pdf (2021)

Elaeagnus umbellata: A miraculous shrub with potent health-promoting benefits from Northwest Himalaya, Saudi J Biol Sci. (2023)

“Autumn Olive: A Potential Alternative Crop,”pubag.nal.usda.gov/download/40095 (USDA National Agricultural Library, Ingrid M. Fordham, Richard H. Zimmerman, and Brent L. Black