Even under the best conditions and despite the most attentive gardening practices, weeds can muscle their way in—fast! While desirable flowers and vegetables can require weeks of coddling to produce blossoms and edibles, weeds seem to shoot up overnight, crowding out desirable plants and stealing the soil nutrients.
Some gardeners shy away from herbicides due to concern for the environment and perceived risk of fruit and vegetable contamination. While you could spend hours pulling, raking, and wielding other weeding tools to avoid using toxic chemicals, consider adding an organic weed killer to your arsenal. These products contain natural ingredients that kill unwanted plants without posing a risk to food production or the environment.
Choosing the best organic weed killer depends on the type of weed invading the vegetable garden, flower bed, or lawn. Ahead, learn what to look for when shopping for an organic weed killer and find out why the following chemical-free products are among the best on the market.
- BEST OVERALL: Doctor Kirchner Natural Weed & Grass Killer
- RUNNER-UP: Green Gobbler Vinegar Weed & Grass Killer
- BEST BANG FOR THE BUCK: Natural Armor 30% Vinegar Natural Concentrate
- BEST SPRAY: Natria Grass & Weed Control with Root Kill Herbicide
- BEST MULTIPURPOSE: Earthborn Elements Borax Powder
- ALSO CONSIDER: ECO Garden PRO Organic Vinegar Weed Killer
What to Consider When Choosing the Best Organic Weed Killer
When buying a safe and effective weed killer, don’t grab the first product that claims to contain natural ingredients. Investigate ingredients and read labels to determine whether the product will kill only specific weeds or all vegetation. Also, bear in mind the difference between natural herbicides that kill existing weeds and those that stop weed seeds from sprouting.
Pre-Emergent vs. Post-Emergent
Like chemical weed killers, organic herbicides come in two types. Pre-emergent, which will destroy seeds or prevent them from sprouting; and post-emergent, which kill weeds that are already growing. The difference is crucial, since once a pre-emergent is in the soil, it will prevent all seeds from sprouting—weed seeds as well as those of desirable plants and flowers.
Selective vs. Nonselective
A selective weed killer will destroy only specific types of weeds but not others. For example, herbicides developed for lawns likely target broadleaf weeds, such as chickweed and clover, but they won’t damage turf-type grasses.
Nonselective weed killers will kill all vegetation, both weeds and desirable plants, so gardeners should use them with caution. To rid an entire yard of dandelions, spraying or broadcasting a nonselective weed killer will kill the grass along with the weeds.
When it comes to natural herbicides, users have very few selective products to choose from; the majority are nonselective and designed to kill most forms of vegetation. They can be used between sidewalk cracks or patio pavers or to create fence lines. They shouldn’t be used near desirable plants and flowers, especially on windy days.
Gardeners may be surprised to find household ingredients, such as vinegar and salt, present in some organic weed killers. Other beneficial ingredients include soaps and essential oils, such as cinnamon or clove.
Lesser-known ingredients, including citric acid, caprylic acid (a coconut oil derivative), and D-limonene (derived from citrus fruits), also feature prominently in many organic weed killers. Manufacturers may combine two or more of the above ingredients to control specific types of weeds.
Natural weed-killing products are available in various forms, with some better suited to specific types of application.
- Spray: Easy to use and offering uniform coverage, most sprays are designed for direct application to the weed’s foliage. There, the spray is absorbed and then travels through the plant, destroying weeds at the root. Take care to limit the spray to just the weeds and avoid applying it on windy days, as overspray could carry the product to desirable plants.
- Liquid concentrate: For gardeners with large crops or heavy weed infestation, a liquid concentrate may be the best option; it can be diluted with water and easily applied over large areas with a pump-type garden sprayer.
- Powder: This dry type of weed killer is usually meant for broadcasting over specific areas to kill weeds without damaging desirable turfgrasses. Like spray herbicides, powder can carry in the wind and kill nearby plants, so choose a calm day to apply it.
- Salts: Products containing salt will kill virtually any plant, so extra care should be taken when using them to keep from contaminating areas of the garden. Depending on the amount of salt, it can take years for it to leach out of the soil, and until then, it might be difficult to grow anything there. Salt-based weed killers are often best suited for application between patio pavers or sidewalk joints rather than in flower beds.
Our Top Picks
To qualify as a top pick, an organic weed killer should be potent enough to kill the weeds causing the problem. It should also contain chemical-free ingredients that will not contaminate fruits and vegetables or leave harmful residues in the environment.
The best organic weed killer will vary from gardener to gardener, depending on individual needs and weed type. The following weed killers contain natural ingredients and will kill a range of weeds.
Containing ocean salt water, vinegar, and soap, Doctor Kirchner’s Natural Weed & Grass Killer tops the list of natural herbicides suitable for killing all vegetation. This non-selective herbicide comes premixed in a large 128-fluid-ounce jug, designed for full strength use in either a garden sprayer or spray bottle.
This liquid is well suited for mow lines or keeping invasive grasses from growing between pavers, as well as sidewalk and driveway joints. This natural weed killer works quickly—plants start wilting within hours. The liquid has a long shelf life, so it will be just as potent the following year.
Say goodbye to crabgrass, dandelions, thistle, and other weeds with just a spritz of Green Gobbler Vinegar Weed & Grass Killer. This natural herbicide is nonselective, so it will kill all vegetation. Beneficial uses include eradicating weeds and tall grasses along fence lines, around patios and pool areas, and in mulched flower beds—but take care not to get it on desirable plantings because they, too, will die.
Green Gobbler contains no toxic chemicals, deriving its potency from concentrated acetic acid (vinegar) to kill weeds without harming the soil or the environment. This product comes in a 1-gallon jug to be used full strength in a garden sprayer or a spray bottle.
To control weeds without spending a lot of cash, consider Natural Armor Concentrate. It comes in a 1-gallon jug at an attractive price, containing vinegar that’s six times more potent than household vinegar. Apply using the attachable trigger sprayer or pour it into a smaller spray bottle or pump-type garden sprayer.
This industrial-strength formula contains only pure and natural ingredients that are environmentally safe. The nonselective vegetation killer is well suited for lawn edging, removing weeds from fence lines, between sidewalk cracks, and patio pavers.
No need to mix or pour Natria Grass & Weed Control into another container—it comes in its own spray bottle, ready to apply. The product contains ammoniated soap of fatty acids, a natural ingredient that penetrates weed foliage to destroy the plant. The product is nonselective, so don’t apply it on a windy day if desirable plants are nearby.
For the best results, spray until weed foliage is saturated. The herbicide travels through the foliage and stems to the roots, destroying the weeds completely and preventing regrowth. Natria won’t contaminate soil: Gardeners can safely sow seeds 5 days after use.
Multipurpose borax can kill weeds, control unwanted insects, and boost laundry detergent—and it’s the sole ingredient in Earthborn Elements Borax Powder. Borax, short for “sodium borate,” is a natural mineral mined in desert regions, including California’s Death Valley.
To use, mix with water at a ratio of 10 ounces of borax to 1/2 cup of hot water, stirring until the powder dissolves. Next, further dilute the solution by pouring it into 2 1/2 gallons of water, then spray it directly on weeds with a spray bottle or pump-type garden sprayer. Like many other natural weed killers, borax is nonselective, so take care to spray weeds only on a calm day so desired plants aren’t affected.
The ECO Garden PRO Organic Weed Killer contains high-strength vinegar for effective natural weed eradication. It comes ready to use and should be sprayed full strength on weeds until foliage is saturated. It’s nonselective, so take care not to let overspray get on desirable plantings.
ECO Garden is eco-friendly and safe for honeybees, soil, and groundwater. It contains no harmful or toxic ingredients, so the user can feel comfortable applying it to weeds in vegetable gardens or around fruiting vines. Results can be seen in as little as 24 hours, and no retreating is necessary.
FAQs About Organic Weed Killers
Natural weed killers won’t leach toxins into soil or groundwater yet will effectively eliminate unwanted plants. If you’d like a bit more info on these products, consider the answers to these frequently asked questions.
Q. Will organic weed killers damage my soil?
It’s possible, mainly if the product contains salt, which can remain in the soil for years before finally washing away. Natural herbicides that contain vinegar or other nonchemical ingredients are less likely to stay in the soil for longer than just a few days.
Q. Are organic weed killers completely safe and free of toxic elements?
When used as directed, most organic weed killers are considered environmentally safe. Always read the warnings: Just because a product is natural or organic, doesn’t mean it won’t emit fumes that can cause headaches or other symptoms. Also, it doesn’t mean the product can be ingested without health risks. Keep all weed killers, organic or otherwise, out of the reach of children and use only as directed.
Q. How often can I use organic weed killers?
That depends on the product. Most sprays can be used whenever new weeds appear, and some may require two or more applications to get rid of certain types. Other than salt, most natural weed killers will not alter the soil’s content and can be used as often as necessary, but read all application instructions to be sure.