Securigera varia | Wikimedia Commons
Pennsylvania extension agronomist Fred Grau came across crown vetch that was across more than 10 acres of poor-quality soil in 1935. Penn State records list the release of Penngift crown vetch in 1953. Penn State’s roadside vegetation research says that crown vetch was first used on Pennsylvania roadsides in 1948, and wider operational use began in the 1950s. Crown vetch went from trace amounts in 2003 to covering 46% of the area by 2005 on one Iowa restoration site, and the restoration project was abandoned.
The Pennsylvania State University account says that the plant apparently entered the country as a contaminant in European alfalfa seed, and the farmer who owned the land called it “dot veed” because it kept returning after cultivation. Grau collected seed and took it back to Penn State, where he and colleagues identified the plant as crown vetch, and his work eventually produced the Penngift variety, which was named using “Penn” for Pennsylvania and “Gift” for farmer Robert Gift. The plant had survived in an area little else could grow, with Grau beginning to study it as a possible ground cover, and within two decades, crown vetch was being planted extensively for erosion control and revegetation across North America. The discovery happened near Reading, Pennsylvania, where Grau found the plant growing on harsh cinder and shale soil. Crown vetch was particularly suited to the steep, infertile slopes that were created by road construction, and spreads through creeping stems and can establish on soils that have relatively low fertility, which makes it useful where it was difficult to maintain conventional grass cover. Penn State researchers later documented another problem, which was that the crown vetch planted along roads could spread when soil was moved during construction and maintenance. Its hard seeds can remain viable for years, while its creeping root system can expand outward from established plants. The Forest Service now notes that dense crown vetch can limit the establishment of native herbs, shrubs and trees. The Pennsylvania discovery had begun with a plant that could survive where other vegetation struggled, and the same characteristic that made crown vetch useful for erosion control later made it difficult to contain once it moved beyond the places where people had planted it.
