By Nelly Cuanalo, The Spruce
Baking soda is a non-selective herbicide, so unfortunately it could kill small plants and grass. Use it on isolated weeds, like in between pavers, along the edge of the driveway, or in sidewalk cracks.
Why Baking Soda Works on Weeds
The reason baking soda is effective in killing weeds is that one of its major ingredients is salt. In sufficient quantities, salt’s effect on plants is to dehydrate them.
If you want to kill a weed permanently, this is one way to do it: dry it out so much that it can’t take up water anymore, and the weed will die for good.
Although it takes a higher dosage of baking soda to kill a larger plant (such as a shrub), it’s still advisable to apply baking soda cautiously to shrub foliage when using it to control powdery mildew. When mixing your solution, use one tablespoon of baking soda per 1 gallon of water.
How to Use Baking Soda to Kill Weeds
There are two different ways to apply baking soda to kill weeds. The easiest way is to pour it right out of the box, directly onto the weeds (approximately 1 teaspoon for each weed). Wet the foliage first so that the baking soda sticks to the leaves.
Alternatively (and better), prepare a solution of baking soda and water, pour some of the solution into a spray bottle, and spray the weeds. When using a sprayer bottle, it’s easier to target the weeds. This method prevents the baking soda from blowing away (which is a major drawback of the direct-application method).
Whichever method you use, choose a sunny day to apply the baking soda (rain would wash it off before it had a chance to work). To mix and apply a baking soda and water solution: Add 10 tablespoons of baking soda to a gallon of water.
Shake it to dissolve the baking soda.
Pour some of the solution into a spray bottle.
5 Additional Tips for Killing Weeds Naturally
In addition to using baking soda, there are many other ways to kill weeds naturally.