Plantain weeds are divided into two categories, the broad-leaf variety and the buckhorn variety. The major difference between the two is that the buckhorn variety has thinner leaf blades. Plantain is a perennial that regrows each year and is commonly found in lawns and in the wild along roadsides and in ditches. Killing plantain weeds requires persistence since it can take two to three years to completely eradicate a serious infestation.
Wait until the fall and put on gardening gloves. Look for any plantain weeds that are growing individually away from the major infestation site. Grasp the base of the weed and pull it straight up out of the ground. Place the plantain in a garbage bag and repeat to pull up as many of the plantain weeds as is feasible.
Fill a garden sprayer with an herbicide containing the ingredients 2,4-D or triclopyr. Use the amount specified on the container and add the appropriate amount of water, if required.
Close the garden sprayer and shake it gently for three to five seconds to mix the ingredients.
Point the garden sprayer nozzle at the plantain weeds and spray them with the herbicide until the plants are completely covered and the liquid drips off of the leaves.
Wait seven to 10 days and examine the plantain weeds to see if they are dead. If green areas persist on the plants, apply a second application of the herbicide spray.