Nine Natural Weed Killers

Nobody wants to see weeds emerge from the soil in their yard and garden. Not only do weeds look bad, but they can also kill the plants you worked so hard to grow and support. Commercial weed killers are quite harmful, and that’s why so many people look for natural alternatives.

Natural weed killers, like salt, boiling water, and horticultural vinegar, kill weeds without harming the environment. However, you must be careful when applying them, so you don’t accidentally touch the surrounding plants. Other natural weed killers, like citrus oil, distilled white vinegar, and organic mulch, are also quite effective.

You must be careful and apply natural weed killers on the base of the weeds, or you’ll kill your favorite plants. Prevention is just as important as killing existing weeds, so carefully plan your approach. Follow along as we highlight nine natural weed killers and help you take control of your yard and garden this summer.

How To Kill Weeds Naturally

An increasing number of people now care about what they use in their yards and gardens to control or kill weeds. Many pesticides, insecticides, and herbicides are highly toxic and can harm the ecosystem. You can easily get the job done using one of many natural weed killers.

1. Boiling Water

Before you try any DIY weed-killer alternatives, you should at least use boiling water to kill the weeds on your property. This is among the best natural weed killer because it’s eco-friendly and easy to use. However, you can’t necessarily pour boiling water all over your yard and garden. Doing so will damage any other plant it touches, as thermal shock can destroy vital plant cells.

Only pour boiling water on weeds that aren’t too close to your favorite plants. Many people use boiling water to kill weeds growing through the cracks and gaps on their sidewalks and driveways. When using this method in your garden, pour it slowly and make sure none of it splashes onto nearby plants. Focus on the base of the weeds to destroy the roots, but stay clear of any growing next to your favorite plants, as you may damage their roots, too.

2. Salt

Too much salt can dehydrate you, and it can also dehydrate weeds. Unfortunately, salt doesn’t discriminate, so be careful with where you use it. Salting weeds in a soil bed full of gorgeous flowers can be risky, as you may kill your favorite plants. It's best to primarily use salt to kill weeds in your driveway, sidewalk, walkways, and rock garden.

Ideally, sprinkle a generous handful directly onto the weed’s base to dehydrate it. You may need to dig around the soil or rocks to expose the area so you can apply it directly. Otherwise, mix one part salt with 3 parts boiling water and spray the weeds. That way, you can cover more ground and ensure the salt seeps into the weeds’ roots. Take care not to spray nearby plants, or else you’ll dehydrate them, too.

3. Horticultural Vinegar

As the name suggests, horticultural vinegar is primarily used as a natural herbicide. It has a 20% to 30% acetic acid concentration, which means it’s more potent than white vinegar. As strong as it is, you can’t carelessly apply it, or else it will be ineffective. For example, spraying the weeds’ leaves and stems will burn them, but it won’t necessarily kill the roots. Of course, it can also scorch the surrounding plants, so you must be careful.

The key is to expose the weed’s base as much as possible and then spray. Keep in mind that horticultural vinegar can also burn your hands and eyes, so wear gloves to prevent burns, and don’t spray horticultural vinegar if your face is too close to the weeds. Otherwise, you may burn your hands and eyes.  

4. Vinegar And Salt

While horticultural vinegar is stronger than white vinegar, white vinegar is still quite effective. That’s especially true when mixed with standard household table salt. The vinegar’s acetic acid will break down plant cells, and the salt will dehydrate the weeds. Fill a pump sprayer with up to 1 gallon of white vinegar, and then add a cup of salt.

Some people add a tablespoon of mild dish soap to help the solution stick, but, of course, that’s not a natural solution. That said, it’s worth using dish soap if you don’t mind adding an artificial ingredient to your natural weed killer. 

5. Smother Them

You don’t necessarily need to douse your weeds with anything special to kill them. Instead, you can deprive them of water and sunlight until they die and decompose. There are a few ways to smother weeds, but you must first survey the area. That’s important because the last thing you want to do is smother your favorite plants’ roots.

Identify weeds that aren’t growing too close to desirable plants, and tarps or cardboard. Next, lay the tarp or cardboard over a patch of weeds, covering as much of the surrounding soil as possible. If it doesn’t feel secure, weigh the tarp or cardboard down with a sandbag or large rocks. That way, it won’t blow away and let oxygen reach the weeds’ roots. It may take 7-10 days to kill the weeds, if not longer.

6. Organic Mulch

Smothering weeds is an effective way to kill them without chemicals. However, it's risky because it can kill surrounding plants. That’s not a problem with organic mulch, which can smother weeds while also infusing the surrounding plants with vital nutrients. Organic mulch consists of everything from tree bark and grass clippings to compost and wood chips.

These materials slowly decompose and release nitrogen, potassium, phosphorus, calcium, and magnesium into the soil. Organic mulch creates a barrier that keeps weeds at bay and stops them from popping up. Mulch offers many other benefits, such as moisture retention and soil temperature regulation. The key is to apply 2” to 4” of mulch to suppress weeds and help retain moisture. Replace the mulch once annually for the best results.

7. Use Groundcover Plants

Today, groundcover plants are quite popular for their unique appearance and growth style. However, not everyone realizes that they have practical uses, especially if you struggle with weeds. Groundcover plants can crowd, suppress, and kill weeds, all without the use of artificial weed killers. They compete with weeds and soak up as much water, sunlight, and oxygen as possible.

Many groundcover plants grow quickly, so it won’t take long to shade the weeds out. Ideally, you should pull existing weeds before planting groundcover plants. That said, be careful not to put any invasive species in your yard, as many groundcover varieties are invasive. That includes English ivy, creeping Jenny, kudzu, and Japanese honeysuckle.

8. Till The Soil

You won’t struggle so much with weeds in your yard if you till the soil once or twice each year. This involves breaking up the first 6” to 8” of soil to aerate it and prevent compaction. Along the way, you will also likely tear and cut weeds into pieces, effectively killing them. It’s a great idea to invest in a small rototiller, so you can till your yard and garden each year. Under the right conditions, this will make seed germination easier, prevent soil compaction, and keep weeds at bay. 

9. Citrus Oil

As much as many people love oranges, limes, and lemons, citrus oil is not loved by weeds. Today, you can find citrus oil extract, which typically contains d-Limonene, and use it as a potent weed killer. Citrus oil offers the best of both worlds, as it damages plant cells and dehydrates weeds. It’s potent enough to hurt the weed’s waxy protective coating. Some people even mix citrus oil with salt to maximize the effects, but that’s not always necessary.

However, be careful and only apply the citrus oil to the weed’s base. Otherwise, you may burn the leaves and stems, but it won’t kill the weeds. Check the weather forecast beforehand to ensure there is no rain in the forecast. That way, the citrus oil can work its way into the weeds and kill while it's still dry out.

Summing It Up

The best natural weed killers are boiling water, salt, and horticultural vinegar. You can also naturally kill weeds by mixing white vinegar and salt and spraying at the base of the weeds. Otherwise, you can deprive weeds of sunlight and water by smothering them with tarp, cardboard, and mulch.

Related Guides:

• How To Prevent Weeds In The Spring
• What To Do When Your Neighbor’s Yard Is Full Of Weeds