Annual rye grass is a popular grass used to overseed home lawns during cold winter months. It is also frequently grown as a cover crop to provide food for grazing cattle. Rye grass grows in bunches rather than individual blades and is characterized by a yellow at the base which develops into dark green leaf blades. Although rye grass typically only survives one year, if the grass produces seed before dying, the seed will sprout the following year.
Wait until the daytime temperatures climb above 50 degrees Fahrenheit and the nighttime temperatures are no lower than 40 degrees Fahrenheit. The herbicide application process should also occur only during dry periods with a lot of sun, as rain will wash it away before it can kill the rye grass.
Fill a 3-gallon garden sprayer with a non persistent-contact herbicide made for weeds, not grass. This is a herbicide that is designed to kill weeds on contact and does not remain in the soil. Herbicides containing glyphosate are especially effective at killing rye grass.
Point the nozzle downward at a 45-degree angle to the ground. Spray the entire surface of the ground with a thin layer of herbicide and allow it to dry.
Wait two weeks and examine the lawn for new rye grass which may have sprouted from seeds. Apply a second application of herbicide if evidence of new rye grass is found.