Arlington County police spokeswoman Det. Crystal Nosal says the protesters were charged Tuesday with trespassing. They were among 21 people protesting the ban on hemp farming.
Hemp is related to marijuana and currently all hemp products sold in the U.S. must be imported.
The Hemp Industries Association is lobbying lawmakers on Capitol Hill to decriminalize hemp farming for products like clothing and rope.
A farmer from North Dakota and another from Vermont were arrested. Police say they had shovels but did not appear to have any drugs and caused only minor damage to the lawn.