Monsanto developed its popular Roundup Original herbicide product as a systemic glyphosate-based herbicide. Once sprayed onto plants, the plant absorbs the chemical through its foliage and stems. Annuals will begin to die within four days. Perennials will start turning yellow and dye within a week, according to Monsanto. Spray Roundup on your landscape to control weeds and other unwanted plants.
Wait for a dry, sunny day when no rain is in the forecast for 24 to 48 hours.
Fill a plastic hand-held sprayer with 1 gallon of water. Add 2 or 2.7 oz. of Roundup Original, using the larger amount only if a recent application of Roundup didn't kill all the plants.
Close the hand-held sprayer. Shake it to thoroughly mix the contents.
Stand with your back to the wind and face the targeted plant.
Spray the solution onto all exposed surfaces of the plant. Apply enough to evenly moisten the entire plant, but not so much as to cause dripping or puddling.