How to kill weeds naturally – for real

Every year between April and June, I go on a weeding mission to eradicate garlic mustard. I pull out every one of those noxious, very invasive weeds I can get my hands on and pull them out. Mastering garlic mustard – or any weed for that matter – is a gradual process that requires elbow grease, a tool or two, and persistence.

However, as more homeowners and gardeners try to avoid glyphosate (the active ingredient in Roundup and other herbicide products), they are turning to natural alternatives. And while there are tons of DIY formulas online, it’s not necessarily a good idea to mix your own. Read on for some demystification, as well as other ways to kill weeds naturally and safely. Oh, and how you can stop weeds growing in your garden in the first place, of course.

Homemade weed killers can be suspect

Making your own weed killer with readily available and affordable ingredients – such as vinegar, salt, dish soap, baking soda, and other household chemicals – does not make it a “natural” weed killer. Just because you frequently use these products in your home without ill effects doesn’t mean you should use them in your garden. As Michelle Wiesbrook, a weed science extension specialist at the University of Illinois points out, unlike registered products, homemade weed killers haven’t been thoroughly tested. Their long-term environmental effects are unknown and they can potentially do more harm than good. Commercial weed killers are usually formulated to break down or dissipate in a controlled manner and within a certain amount of time. On the other hand, a weedkiller made with the household cleaner sodium borate (Borax), is very mobile in the soil and can unintentionally damage nearby plants that you want to keep.

There are also other risks to consider, according to Wiesbrock. Vinegar, one of the most recommended weedkillers, only works when it is highly concentrated. Horticultural vinegar contains 20-25% acetic acid, while household vinegar is only a 5% acetic acid solution. When mixing the highly concentrated vinegar with water, you must be extremely careful as splashing can lead to permanent skin burns and eye damage. And using boiling water on your weeds (another frequently recommended way to kill weeds) isn’t without risk either. Depending on how many weeds you need to kill, that means dragging several containers full of boiling water through your garden – you can imagine how dangerous that could be.

Instead of a homemade weed killer, try using a biological herbicide listed by the Organic Materials Review Institute (OMRI) for biological use. Look for the “OG OMRI” label on the product packaging. If you have qualms about it being more expensive than your own homemade concoction, consider the possible costly damage to other plants, environmental contamination, and health risks to your family and friends. pets.

Identify your enemy

Often, home gardeners instinctively opt for a weedkiller when it is not needed. I cringe when I see people walking around their yard pulverizing every dandelion, a job that can be done just as well and in the same amount of time by removing the dandelion and its roots with a soil knife or digger. dandelion.

Before applying weed killer, determine if you are dealing with a few weeds that can be pulled out by hand or an infestation which justifies the use of a weedkiller. Also decide if it really is a weed that needs to go. Having a goldenrod or milkweed, for example, can be beneficial, as these plants attract butterflies and pollinators. Native insects have far too few food sources available in our home gardens and by leaving some of these plant volunteers alone you are contributing to biodiversity and the entire food chain.

Amazingly, this even applies to plantains, a non-native weed commonly found in lawns. As Doug Tallamy, founder of Homegrown National Park, writes in his book, Nature’s Best Hope, plantains provide food for the yoked bow moth, buckeye moths, and giant leopard moth. The latter is so strikingly beautiful that after spotting one in our garden last year, I look at the plantains in our lawn in a whole different way.

Burn your weeds

When you manually pull weeds out of the ground, it brings the weed seeds to the surface where they will begin to sprout. A flame weeder does not disturb the soil and it is safe for the environment as it does not involve any toxic chemicals. Using a flame weeder can be an effective and chemically neutral way to kill weedsespecially those that grow in gravel driveways, between patio pavers, or in sidewalk gaps where they are difficult to remove manually… but they are not without their drawbacks.

The downside is that flame weeders don’t work well on weeds taller than two inches and they don’t kill the roots. Perennial weeds will regrow; therefore, flame weeders are best used on annual weeds. Keep in mind that a flame weeder creates extreme heat (up to 2000 degrees Fahrenheit) and it should be used with the utmost cautionnever in dry conditions or near fences or structures that could catch fire.

Remove your weeds

Ideally, you’ll prevent weeds from growing in the first place. There are two ways to do this: planting densely or applying a thick layer of mulch. Weeds will grow anywhere from bare ground, so don’t give them a chance. In a newly planted yard or perennial bed, you can also use annuals such as wildflowers to fill in the empty space, and mulching not only suppresses weeds, but also maintains moisture in the soil, which which reduces your need to water your plants.

Smother your weeds

If you’re not in a hurry, depriving weeds of sunlight, air, and water can be an effective way to treat a larger weed-infested area. Cover the area snugly with a durable agricultural black plastic tarp and secure it with landscape pins or plenty of rocks so it won’t blow away. You can weigh it down further with a thick layer of mulch, leaves, twigs or small branches. It may take a season or more for the weeds to die before you can remove the plastic and replant the area.

I’ve also used this method successfully on other unwanted plants, including Houttuynia cordata, aka chameleon plant, a horribly aggressive ground cover. I couldn’t remove it by any other method because as long as there are bits of roots left in the ground, it grows back.

Be a smart handheld weeder

No matter what you do, there will always be weeds that require manual removal. Because hand weeding is heavy and physically demanding, be a smart weeder: use sturdy, ergonomic tools, learn to let the tool do the work (not your wrists and back), weed after a rain when the ground is soft, and pull weeds out while they are small and before they set seed and spread further. Always make sure to delete all root system in order to get rid of the weed once and for all.

Some weeds, like the famous garlic mustard, should never be composted, as their seeds remain viable even in a warm compost heap. To dispose of them safely, place them in plastic bags and throw them in the trash.

In short, there are many ways to control weeds without using your household chemicals. So you can leave them for what they are intended for: cleaning your house.

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