Although creeping Charlie (Glechoma hederacea) also is known as ground ivy, it actually is a member of the mint family. Once cultivated for medicinal purposes, creeping Charlie now generally is considered a weed due to its invasive spreading habit. Borax is a boron compound, and used primarily in detergents. It kills creeping Charlie by interfering with the plant's sugar transportation. Apply the borax solution on a warm day when the creeping Charlie is actively growing.
Practice your spraying technique prior to applying the borax solution. Agents with the University of Minnesota Extension suggest filling the tank sprayer with water and briskly walking the area to be treated, spraying as you go. Pass the wand back and forth over the area to be treated until you get the feel of how much spray it will take to evenly cover the area infested with creeping Charlie, without saturating the surrounding soil.
Dissolve 1 1/4 cup of borax in 1/2 cup of warm water. Pour the mixture into 2 1/2 gallons of water in a tank sprayer.
Spray the creeping Charlie until it is dripping with the solution. Do not water for 48 hours and then water as you normally do. The creeping Charlie should die within one week.