Calcium Chloride As a Weed Killer

Rural road Calcium chloride controls weeds and dust that may spring up on a rural roadway. Image Credit: Jupiterimages/Comstock/Getty Images

Calcium chloride will effectively kill annual weeds and stunt or severely set back perennial weeds. It is a non-toxic, safe way to kill weeds and does not cause soil sterility. Calcium chloride not only gets rid of weeds, but also effectively controls dust and helps to stabilize the soil.

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Moisture Retention

Because calcium chloride has the ability to absorb moisture from the atmosphere, consider using it on dirt driveways or pathways in regions with greater than 30 percent humidity. The substance will absorb approximately four to ten times its weight in moisture during the night hours, according to Hills Brothers Chemical Company. It will continue to hold up to half of the water during the hot daytime hours.

Rural Roadways

Weeds can quickly overtake a rural roadway. Using calcium chloride will control the dust of the dirt road and keep weeds at bay. Your visibility will be greatly improved when driving down the dirt road because the calcium chloride will keep the soil moist so it does not billow up in a dust cloud. You will also not have to worry about controlling the roadway's weeds with herbicides or hand-pulling.


The USGA Green Section Record suggests mixing calcium chloride at a ratio of 2 pounds for every square yard of top soil. The substance will not adhere to your shoes when you walk through soil that contains the substance so there is no fear of spreading the substance to lawns or ornamental plants.

Dangers and Yearly Application

Calcium chloride will build up in the soil after years and years of application, so you will not need to use as much each year to control weeds and dust. It is a corrosive substance, so wash automobiles and lawn machinery regularly to remove the calcium chloride-laden mud and reduce the risk of corrosion. The substance is widely available for dust and weed control, and it comes in bags or steel drums.