How to control Russian olive tree, an invasive species in America

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The Russian Olive tree, as opposed to native American silverberry, is a highly invasive species in some parts of the United States and Canada.

The latin name of this tree is Elaeagnus angustifolia. Though it looks very similar to the common olive tree,  they belong to different plant families. Getting rid of Russian olive is very labor-intensive but quite straightforward.

• See if Russian olive is invasive in your area

Russian olive tree, a short story

This short tree is actually native to central Asia and Eastern Europe. Reports of its use date back to ancient Persia and India, since edible Russian olive fruits were harvested for oil.

This hardy and vigorous plant spread to many parts of Europe, and until today, Russian olive is used there as an ornamental and useful shrub.

The many qualities of Russian olive set the stage for its introduction in North America: a fast-growing, resilient plant was needed to stave off erosion. In the early XX^th century (1900s), horticulture stores imported Russian olive and sold it to their customers. It helped mark property edges, stabilize river banks, provide melliferous flowers for bees and serve as wind-resistant ornamental hedges.

Russian olive then started spreading and overcrowding native vegetation. The very reasons for which it was imported led to an imbalance in local vegetation. Upcoming generations are now learning to control Russian olive, truly a force unleashed by their forefathers.

• Do you live in Russian olive’s native habitat? Read more on how to plant and care for Russian olive.
• Russian olive thrives in the same type of habitat as tamarisk, another invasive shrub.

Controlling Russian olive, raising awareness

Take local action against Russian olive

What makes dealing with this plant quite difficult is that it’s also very appealing. Fruits are useful and the fragrance is nice, so it’s difficult to raise awareness about the invasiveness of Russian olive.

Moreover, getting rid of Russian olive is a bane because of its thorns and the vigorous growing back. Even persons who understand the issue don’t easily engage into the work-intensive labor required.

But it actually isn’t so difficult to reduce Russian olive infestations once your mind is set to it.

Local regulations written to control Russian olive

In both the United States and Canada, local governments where the plant has become invasive have added Russian olive to their noxious weed list. The local Department of Agriculture can inform you on whether your area is subject to restrictions on growing Russian olive.

Possible restrictions can be that:

• it is illegal to plant, grow or cultivate Russian olive,
• sale of Russian olive not allowed,
• transplanting Russian olive is not permitted,
• commerce or sharing of Russian olive seeds is disallowed,
• cutting down or removing of existing specimens is mandatory.

Usually, local ordinances and governments can support taking action through:

• Russian olive weed-control programs,
• propagation maps and zone reports,
• dedicated forest management teams and task forces,
• stipends or grants to refund expenses for removing Russian olive,
• hotlines or complaint lines to report places where Russian Olive grows.

How to stop invasive Russian olive

As said earlier, it’s very labor-intensive to wipe out Russian olive trees over a wide area. However, it is possible, and the recommended method to kill Russian olive without endangering native plants is the cut stump method.

• Wear protective clothing against thorns.
• Cut the Russian olive at the stump as low as you can.
• Apply a natural herbicide directly on the stump along the outer growth rings.

Remember that if you don’t apply the herbicide, the Russian olive will grow back even more vigorous than before. High-strength vinegar will do the trick.

A few tips on how to make weeding out Russian olive easy:

• Use a chainsaw or even heavy forest machinery to speed the cutting up, if you’ve got a large surface to cover.
• Work as a team, with one person cutting and the other spraying the natural herbicide on the cut stump.
• Check that you also get rid of smaller trees and saplings.
• Spray only the outermost growth rings to save on herbicide, since the center won’t sprout anyways. Focus on the live circle just near the bark.
• Seedlings under a year old can be pulled out manually with the root.
• Spray more vinegar on the stump every fortnight for two months.
• Check in subsequent years for new growth.

Other ways to remove Russian olive

Other weed removal solutions are ineffective against Russian olive, unless conducted by professionals. So don’t try to ignite fires, spray herbicide on vast areas, or simply cutting without using herbicide.

Burning Russian Olive

Some pest control specialists advocate for using fire to control Russian Olive. This is possible, but it only works in rare circumstances.

Risks associated to fire far outweigh the benefits.

Indeed, russian olive can sprout back from roots and stump after burning, especially where soil is deep. Precautions for this technique to work are:

• Involve the local fire department
• Prepare native re-vegetation plants, sow/plant immediately after burning (as soon as the soil is cool).
• Protect area from livestock
• Monitor for re-growth monthly at least

Incidentally, Russian olive is a great species for firewood, so collect any logs, dry them off (at least one whole year), and you’re set for winter!

Biological control against Russian olive

• Here, you’ll find a few advances regarding Russian olive biological control.
• Long-term success is only possible by promoting growth of native plants.

• Read more on how to plant and care for Russian olive.
• An alternative to Russian olive: American silverberry.