Elaeagnus pungens

Silverthorn

Nonnative to FloridaFISC Category 2 Invasive

Species Overview

In the early 1800’s Elaeagnus pungens, or silverthorn, was introduced from China and Japan as an ornamental plant. Silverthorn is used in the United States as a landscape plant, often grown as an evergreen hedge and barrier and is regularly planted along highways. Unfortunately, many Florida nurseries and homeowners are not aware the Florida Exotic Pest Plant Council considers this plant a Category II invasive exotic species. This means silverthorn has the potential to cause ecological damage by altering native plant communities by hybridizing with native Elaeagnus species, displacing native species, and changing community structures or ecological functions.

Species Characteristics

Elaeagnus pungens is an evergreen shrub that is able to grow 3 to 25 feet in height. Although silverthorn is primarily considered a shrub, it also can take the form of a climbing plant, growing over and shading out other plants. Take caution when handling this plant. Its common name, silverthorn, comes from the thorns on its branches.

Impacts

Silverthorn is a fast-growing, weedy ornamental. It is able to grow and thrive in a variety of conditions, and can tolerant shade, drought, and salt. Animals and birds disperse seed, widening its area of distribution. Reproduction also occurs via stem sprouts. When silverthorn is in the climbing form, it can climb into trees, leading to the displacement of native vegetation.

Control Methods

Preventive Measures

Remove all silverthorn plantings to prevent the spread and dispersal of seed. Educate the public on the potential dangers of invasive plants to prevent future plantings.

Cultural/Physical

Remove plants prior to seed production.  Revegetate natural areas with native species.

Mechanical

Aggressive tillage and/or mowing is an option whenever possible.  Repeat as needed to control regrowth. 

Biological

Silverthorn has very few pests or diseases in landscapes. There are no known biological agents.

Chemical

Foliar applications of imazapyr or glyphosate with a surfactant in water have been used to treat silverthorn. Triclopyr as a 20% solution in a petroleum base with a penetrant can be used for upper stem treatments, as well as to young bark as a basal spray. Large stems can be cut and stumps treated immediately with imazapyr (10% solution), triclopyr (50% solution) or glyphosate (20% solution) in water with a surfactant.