4 Natural Ways to Kill Weeds—and Keep Them From Coming Back

Few things are as frustrating as spotting stubborn weeds in your lawn or garden. While your natural instinct may be to reach for conventional weed killers and herbicides, spraying these chemicals on your lawn can compromise the health of your landscaping. Many of these products contain ingredients that can not only kill healthy soil but also make your lawn dependent on chemical treatments. But there are some natural ways to keep weeds out of your lawn. Ahead, we're sharing a few natural weed killers, as well as some preventative measures you can take to banish these pesky plants.

Why Lawn Weeds Are Hard to Kill

Weeds are designed to spread, persist, and usurp ground from less aggressive plants. "Weeds compete with your lawn and other landscape plants for space, water, and nutrients and are often better equipped with high seed numbers and seeds that persist in the soil for many, many years," says Amy Lentz, Colorado State University Extension specialist in horticulture and master gardener coordinator.

For example, bindweed produces over 500 seeds per plant each year, and the seeds will persist and lay dormant in the soil for up to 60 years, says Lentz. That means they are just sitting there in the soil, waiting for their chance to sprout—and for their chance to overtake your lush and healthy lawn.

How to Kill Weeds Naturally

There are a few natural weed killers you can make or buy. However, since none of these nip the weeds at the root, they'll only temporarily solve your weed problem. As with any weed killer, these methods can also damage the welcome grass and plants that surround the weed, so spot-treat as close to the weed as possible, says Kel Giard, CEO of Clean Air Lawn Care, a sustainable lawn care company.

Make a Vinegar Weed Killer

Make a vinegar weed killer to get rid of these prolific plants. Just combine 1 gallon of vinegar with 1 tablespoon of dish soap and spray the mixture directly onto the weeds in your yard. Vinegar contains acetic acid, which acts as a contact herbicide and breaks down the weed's cell walls and removes moisture. Just make sure to target the weeds directly as vinegar can also kill other plants in your yard.

Use Boiling Water

Using water as a weed killer is easy—just bring it to a boil and pour it directly over the weeds in your yard. The weeds will die almost instantly. "This is considered a 'non-selective' option as it will kill everything it touches," says Craig Elworthy, founder of Lawnbright. "It’s better to use this in mulch beds or patio areas."

Use a Weed Torch

Another way to naturally kill off weeds is with a blowtorch made specifically for killing weeds. "These are very easy to use, just point and shoot," says Elworthy. "Once the weed begins to wilt (which only takes a few seconds at most), you can move on." Be careful not to damage your lawn and other plants in the process, and don't use it during an overly dry season or in regions with wildfire risk.

Buy an Organic Solution

If you are going to spring for a spray to nix your weeds, choose ones that have iron as a main ingredient. "Iron can works as a natural weed killer because it wilts the weeds by overfeeding it," Giard says. On broadleaf and grass weeds use non-selective or broad-spectrum herbicides like Burnout, which uses citric acid as its active ingredient, and Avenger, which uses citrus oil. "These use acidity to kill the plants, similar to how the vinegar technique works," says Giard.

How to Prevent Weeds Naturally

The best way to keep weeds out of your lawn is by taking necessary preventative measures.

Prioritize Soil and Grass Health

Keeping your soil healthy is one of the most effective ways to keep weeds out of your lawn. "If you have healthy soil and healthy roots, you'll help prevent weeds before they get going," says Giard. "Using organic fertilizer is one way you can help make sure your soil stays in top shape." Annual aeration and reseeding can also keep your grass flourishing and give weeds less room to take root.

Adjust Your Mowing Routine

While improving the health of your grass can help fight off weeds, your mowing approach also plays a part. "Mow higher—the shorter your grass is, the easier it is for weeds to push through the soil," says Giard. "Higher and thicker grass can also help choke out weeds." Even a subtle change of mowing at 3 inches (instead of 2 1/2 inches) can make a difference. Mowing more frequently can also provide a defense against weeds since it allows you to remove the heads of the weeds before they are able to produce and spread seeds, says Lentz.

Pull Unestablished Weeds

Depending on the size of your lawn, weeding by hand may not be the most time-efficient task. But if you can pull the weeds when they are young and small, you have a better chance of removing the entire root system. "Using a weeding tool or a hori hori knife can help you to easily dig down below the crown of the plant and pop the weed out of the ground," Lentz says. "It is important to try and get as much of the root system as possible when pulling and digging weeds."

Adjust Your Watering Schedule

Weeds often have extremely shallow root systems. If you water your lawn a few times per week for 10 minutes at a time, the water is going to the weeds rather than the root zone of the turf grass. Watering your grass deeply but infrequently is key. "You need to train your roots to drive deeply in search of water and away from the surface," says Elworthy. "Once or twice per week is all you’ll need to water. This starves the weeds of their water source and helps your lawn grow strong."