When I visit with landowners, I have noticed thickets of thorny olive (Elaeagnus pungens) and/or autumn olive (Elaeagnus umbellata) throughout woodlands, especially in bottom lands. It was introduced from China and Japan in the 1830s and was widely planted for wildlife habitat and ornamental purposes. While animals do like the fruits from these olives, they outcompete our native plants, and they are listed as a non-native invasive species. American Beautyberry is a good native alternative to olives and benefits wildlife.
Thorny olive and autumn olive can look similar to one another, but they do have some differences that help with identification. Thorny olive is an evergreen shrub that will grow between 3 to 25 feet in height. The branches have thorns scattered with thick leaves that are silver-brown on their underside. Autumn olive is a deciduous shrub that grows 3 to 20 feet in height. It will also have scattered thorns along the branches, with a silvery underside to the leaves.
The leaves of the thorny olive are alternate and oval to elliptic. The leaves range in size from 0.4 to 4 inches long. The margins are irregular and wavy. Autumn olive leaves range from 2-3 inches long and all the leaves will be elliptic in shape.
The timing of the flowers and fruit can also help in identification. Thorny olive flowers from October to December, while autumn olive flowers from February to June. Fruits of the thorny olive will set from March to June, while the autumn olive sets its fruit from August to November.
Control Methods:
Control methods for both thorny olive and autumn olive are similar and listed below.
- Foliar – Thoroughly wet all leaves.
- Arsenal AC or Vanquish – 1% solution in water applied from April to October. Nontarget plants may be killed or injured by root uptake.
- Basal Bark – For stems too tall for foliar sprays. Apply to young bark as a basal spray from January to February or from May to October.
- Garlon 4 – 20-percent solution in basal oil, vegetable oil, crop oil concentrate, diesel fuel, or kerosene (2.5 quarts per 3-gallon mix)
- Pathfinder II – undiluted
- Cut Surface – large stems and immediately treat the stumps.
- Arsenal AC – 10-percent solution in water (1 quart per 3-gallon mix). Nontarget plants may be killed or injured through root uptake.
- Glyphosate – 20-percent solution in water (2.5 quarts per 3-gallon mix).
Author
Jeff Fellers, Cooperative Extension, Forestry and Wildlife Agent
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