Easier Than Hand Pulling Weeds: Add One Ingredient For A More Effective Herbicide

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For gardeners and lawn experts, weed removal never actually ends. Sure, there are several approaches you can take to preventing and getting rid of weeds in your garden  — but it's an ongoing job that comes with maintaining outdoor spaces. Everything from applying herbicides and pulling weeds out by hand to laying mulch and installing landscape fabric can keep them at bay. There's one ingredient you can add to your herbicide to reduce the number of times you have to spray: ammonium sulfate (also known as AMS). 

Ammonium sulfate isn't an herbicide itself, but it's a common nitrogen-based fertilizing ingredient that you can add to glyphosate to increase the herbicide's effectiveness. Glyphosate is the active ingredient in common herbicides, such as Roundup and Glypro. It's also sold separately, and when combined with water, and sometimes other additives, it works well at eliminating common garden weeds. Many experts recommend adding ammonium sulfate to store-bought glyphosate-based herbicides to increase their acidity. 

Additionally, some experts recommend adding ammonium sulfate if using "hard water" in your homemade glyphosate mix, as it can limit the absorption of the glyphosate into plants. Walmart has it available, like this Hi-Yield Ammonium Sulfate 4-lb bag sold for $20. You can also buy it on Amazon. For example, this Alpha Chemicals Ammonium Sulfate 1-lb bag is available for $10. To buy it locally or in bulk, visit your local nursery, feed store, or agricultural supply store.

As with combining additives to any herbicide, it's best to follow the instructions for guidance on volume and the order to add them. But if your label doesn't have any, here's an easy reference you can use when adding ammonium sulfate to glyphosate. The ammonium sulfate will first need to be diluted in water before being added to the glyphosate mix or store-bought solution.

Before creating your DIY herbicide solution, cover surrounding plants or lawn areas that may accidentally be sprayed — this solution doesn't discriminate between weeds and the plants you want to keep. Next, don a pair of protective gloves and add 1.4 ounces or roughly 4 tablespoons of ammonium sulfate per gallon of water. Shake up your application container (or use a mixer to agitate the mixture), as the ammonium sulfate should be fully dissolved before use. 

Then add in your store-bought herbicide at the rate listed on that specific product's label, as glyphosate concentration varies by brand and product line. Then, apply your DIY solution to weeds as you normally would. Keep in mind that it'll take some days before you see any necrosis on the weeds. However, once they've cleared out, it's the perfect time to prep your soil for a spring garden if you're planning to fill that space with new plant friends.