Abstract: Perennial weeds are controlled by deeply placing selected volatile chemical soil fumigents, 14 to 24 inches below ground level, at 18 to 30 inches of horizontal spacing, and applied at rates ranging between 2.5 to 30 gallons per acre, to destroy their vegetative and reproductive roots. Examples of such perennial weeds that are effectively and economically controlled and/or eliminated are morning glory, which is also called field bindweed or Convolvulus arvensis and Canadian thistle, which is also called Cirsium arvense. Examples of the volatile soil fumigants are respectively: 1-3 dichloropropene and related chlorinated C 3 hydrocarbons containing fumigants known by various marketing names and symbols, such as Telone, Vidden-D DD, 1-3 D, and Vorlex; Methyl bromide contaning fumigants known as M. B.; and/or ethylene dibromide containing fumigants known as E.D.B.