How to Organically Kill Weeds Without Harming Your Plants

Keeping weeds under control doesn't have involve harsh chemicals.

No matter how much careful planning you do, it's inevitable that annoying weeds will start popping up in your garden. When you spot them, don't reach for a chemical weed killer—there are natural ways to kill weeds in an environmentally-friendly way. In the event you spot just a few weeds sprouting in your flower bed, you can try simply pulling them out, digging out as much of the roots as possible. But if you're seeing more and more weeds taking over, a natural remedy can help you take back your yard.

woman's hand dandelions roots against rustic green door
Peter Krumhardt

Chemical-Free Ways to Kill Weeds

If you'd like to avoid using harsh chemicals of any kind in your garden, first try these natural ways to kill weeds.

Mulching

Anything that covers and smothers weeds is a type of mulch, including biodegradable products like cardboard and newspapers. Mulch also helps conserve moisture. An organic mulch works best in two ways: It offers weed control, and it breaks down to make your soil more fertile. Use a 2- to 4-inch layer of organic materials, like pine bark, straw, clippings from a non-chemically treated lawn, or bark. Wood mulches, however, draw nitrogen from the soil in order to break down, so they're robbing nitrogen and nutrients from your plants. Avoid placing mulch right up to the trunks of trees or stalks of plants, which can lead to disease or decay.

Solarizing

During the heat of summer, place thin clear plastic across any area where you want to kill weeds. Leave the plastic in place for four to six weeks. The sun heats the ground and kills weed roots and seeds, but the intense heat also kills beneficial organisms.

Flaming

You can also use a propane torch ($25) The Home Depot to scorch weeds. But use extreme caution. Wait until a wind-free day, as flaming will also kill nearby grass and other plants, so it's best for use in areas without planting you want to keep, such as between the cracks of a concrete sidewalk. Never use flaming in fire-prone regions.

Hand Weeding

Grab a dandelion weeder ($10) The Home Depot, which is a tool with a forked end, made to dig deep into the soil to loosen and pry up a weed's roots. There are even long-handled versions that allow you to stand while removing weeds. If any roots remain in the soil, they may regrow, so without the right tools, the next best thing is pulling the plant out as close to the roots as possible.

Boiling Water

Boiling water kills plant tissues, but like flaming, the stream of water can be hard to control if you're trying to do spot weeding.

Weed & Grass Killer Weed Prevention
Courtesy of Amazon

Natural Weed Killers

Any herbicide you choose, whether it's an organic (sometimes called "natural") compound or a synthetic one, has its benefits and drawbacks. These organic weed-killer products work, but they also have certain limitations.

Vinegar

Acetic acid is the active ingredient that makes vinegar a weed killer. White vinegar contains about 5% acetic acid. This level of acetic acid burns the tops off weeds but is less likely to kill anything with well-established roots. For a vinegar weed killer to be most effective, you'll have apply it frequently. It can also kill nearby plants if you're not careful.

Corn Gluten Meal

Dr. Nick Christens at Iowa State University discovered that corn gluten meal ($45) Ace Hardware, a byproduct of corn milling, works well to prevent seeds from growing. This pre-emergent organic herbicide is often sold as a lawn weed-control product. In order for it to be effective, you have to apply it at just the right time in spring before weeds begin to sprout. In addition, it usually takes a few years of consistent applications to reach its full potential. Just avoid applying corn gluten meal in any beds where you plan to sow other seeds, since it'll prevent them from growing

What Not to Use: Salt

While it's true that salt kills plants, including weeds, it also poisons the ground for many years and moves into groundwater sources after rain or watering. It's a bad idea to use it anywhere in your yard, so steer clear of homemade weed-killer recipes that call for salt or Epsom salt, vinegar, and dish soap. Both the salts and soap are toxic to the environment and should be avoided.

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