Weeds. They’re every gardener’s worst enemy, weaving their way through our perfectly planted gardens and reeking all kinds of havoc en route.
So, with spring just around the corner, it’s no wonder you’re now trying to work out how to make homemade weed killers that eliminate these persistent pests once and for all.
Sure, you could head out to the store and stock up on some chemical-laden weed killer, but let’s face it:
That’s not exactly the safest option, is it?
Even chemicals that are relatively low in toxicity can cause all kinds of harm if accidentally ingested by our pets or children, while research carried out by the US National Toxicology Program’s (NTP) found that the combination of chemicals in products like the best-selling Roundup are far more toxic to humans than any single active ingredient on its own.
That’s to say nothing of the long-term environmental damage that can occur when commercial herbicides get into our soil and water supplies.
So yes, natural weed killers seem like a good way to go, but how exactly do you make them?
Making homemade weed killer keeps your garden looking at its best in a way that it is cheaper and safer than using chemical-based products from a gardening center.
More importantly, do homemade weed killers even work in the first place?
Today, we’ll answer both of those questions and more besides in this complete guide to ridding your garden of weeds without relying on commercial herbicides.
Does Homemade Weed Killer Really Work?
All homemade weed killers work to an extent, but there’s really no substitute for digging out invasive plants by hand.
There’s good news and bad news when it comes to homemade weed killers.
First, the good news:
All of the solutions you’ll read about today are effective in killing off the foliage of most common garden weed types.
The bad news, however, is that they have little effect on the roots, meaning the weeds will eventually grow back and have to be dealt with all over again.
For the best results, you’ll benefit from using the following process.
1: If necessary, use a weed eater to trim down excessive weeds as much as possible.
2: Use one of the homemade solutions listed here to kill off the remaining foliage.
3: Get a good pair of gardening gloves and a trowel and dig up the roots manually to stop those irksome weeds from growing again.
Sure, this requires a lot more hard work than simply blasting those weeds with a spray, but it really is the most effective method for permanently eliminating weeds without relying on store-bought solutions.
How to Make Homemade Weed Killer
Using a homemade weed killer is not only safer than relying on chemical-based commercial products, it’s also a much cheaper way of controlling weeds in your garden.
All of the following solutions can be put together using the kind of everyday items you likely already have lying around your home.
1: Salt and Vinegar
Mixing salt and vinegar together can create a powerful, long-lasting natural herbicide
Individually, both salt and vinegar are known as powerful natural weed killers.
One of the few solutions to get right down into the root system, pure salt will starve both leaves and roots of moisture and dehydrate them.
For small patches of weeds, you can add salt directly to the plants and soil. For larger areas, consider mixing salt and water in a spray bottle and spraying onto the weeds.
You can also use vinegar in much the same way, but please note that only vinegar which is at least 5%+ acetic acid will work.
Having said that, the most effective approach is to mix the two into a much stronger solution:
How to Make a Salt and Vinegar Weed Killer
What you’ll need:
- 1-gallon bucket
- Long-handled spoon
- Plastic spray bottle
- 1-gallon 5% acetic acid vinegar (standard white vinegar should work)
- Dishwashing liquid
- Table salt.
How to make it:
Mix one gallon of 5% white vinegar with one cup of table salt in a bucket and use a long-handled spoon to stir it until the salt completely dissolves.
Next, add two tablespoons of dishwashing soap and stir thoroughly. The liquid soap will act as a surfactant to ensure your solution sticks to the weeds.
With that done, use the funnel to pour your weed killer into a spray bottle and spray it onto your weeds, ensuring you thoroughly coat all surfaces.
Finally, funnel any remaining solution into a clearly labeled, well-sealed container and store it in a cool, dark place until the next time you need it.
The Drawbacks of Salt and Vinegar Weed Killer
Few natural remedies work better than the soap/salt/vinegar solution. If used correctly, this should ensure those troublesome weeds are gone for good.
However, its effectiveness is also one of its major disadvantages.
The solution is so effective that if enough of it gets into your soil, it will damage it to the point that you’ll be unable to successfully grow anything in that area again.
As such, it pays to exercise caution and only spray directly onto the weeds, avoiding the soil as much as possible.
You’ll also benefit from waiting for a calm day before you spray your weed killer. If a breeze takes hold as you’re spraying, it could transfer your weed killer onto your regular plants and kill those too.
2: Lemon Juice
When it reacts with heat from the sun, the citric acid in lemons works well at burning weeds away
If you’re growing lemons on the fruit trees in your garden, then you’ve already got a strong natural weed killer close at hand.
Lemons contain high amounts of citric acid which is excellent for burning off unwanted weeds.
How it Works
Simply squeeze as much fresh lemon juice into a spray bottle and spray it onto the offending plants. They should shrivel away and die within one or two days.
For the best results, wait until a hot, dry day to douse your weeds in lemon juice.
If you don’t have fresh lemons available, or if you just don’t have time to squeeze them, store-bought juice like Realemon’s 100% Lemon Juice will work just as well.
Adding Lemon Juice to Vinegar
Lemon juice should work well on its own, but if you’re not getting the results you need, try mixing it with vinegar.
Four ounces (113 ml) of lemon juice mixed with a quart (roughly 1 liter) of vinegar can prove to be a potent weed killer.
Be warned, however, that even though it’s non-toxic, this highly acidic solution can still sting if it gets in your eyes, so wearing safety goggles is advised.
Use old newspapers as a ground layer to starve weeds of the light they need to grow
Planning to use newspapers to keep your garden weed-free? This handy video explains just how easy it is.
Here’s a quick, cheap alternative to weed killer and landscaping fabric that proves to be many a gardener’s best defense against weeds:
Lay down some old newspapers and smother the soil so that nothing can grow there.
Newspapers are porous, so the plants you *do* want to grow will still get all the water they need. Yet they also do a great job in blocking out light, meaning weeds won’t be able to grow again.
How to Use Newspaper to Prevent Weeds
Quick and easy though it may be, there’s a little more to it than just putting newspaper sheets on top of your soil.
Think about it:
One light breeze and those papers will soon scatter, littering your otherwise immaculately-kept garden.
Instead, it pays to follow a simple process:
1: Use a weed eater or trowel to manually remove any existing weeds.
2: Next, prepare the soil by watering it thoroughly.
3: Lay down the newspaper on the offending areas, being sure to stop as you approach the root system of any plants that you want to keep.
Typically, four sheets of newspaper layered on top of each other will work best.
4: Be sure to overlap the edges of the newspaper sheets so that there are no gaps where weeds could breakthrough.
5: Spray the newspaper with a hose. This will ensure that it sticks to the soil and doesn’t blow away when it gets windy.
Many professional gardeners recommend adding a layer of mulch on top of your newspaper, though we’ve also seen it work without.
4: Boiling Water
Slowly and carefully pouring a kettle of boiling water on weeds works well in removing them from gaps in pavements and driveways
When it comes to natural weed killer alternatives, they don’t come much simpler, or cheaper, than this.
Fill a kettle or pan with water, bring it to the boil, and pour it on your weeds.
Unfortunately, this isn’t a permanent solution. Although boiling water works remarkably well at killing off the foliage, it doesn’t affect the root system, so the weeds will grow back eventually.
That said, this proves a great way to temporarily get rid of those pesky weeds that grow in between the cracks of your driveway or sidewalk until you have time to come up with a longer-term fix.
Vodka and gin work well at burning off the foliage of garden weeds, but rarely kill the roots, meaning those weeds will likely grow back.
Don’t worry, the vodka isn’t there so that you can drown your sorrows after those terrible weeds appear in your garden, though you might want to save some to celebrate your new weed-free garden afterward.
Vodka works surprisingly well as a weed killer alternative, though before you go running to the liquor cabinet, there’s something you should know:
It only works on certain types of invasive plants.
To be specific, you’ll have the most luck using vodka on broad-leaf weeds such as chick weeds, plantain weeds, dandelions, and wild onions.
To be even more specific, you’ll get the best results by spraying vodka on your plants when the weather is good.
Vodka works as a weedkiller by reacting to the sun’s heat to burn through the plants, so wait until a hot, sunny day before you try this one.
When you’re done, give the weeds a few days to die off, then remove and dispose of them to prevent their seeds from repopulating.
Using Other Types of Alcohol to Kill Weeds
Don’t have any vodka at home? A cheap bottle of gin will work just as well.
Alternatively, you can use Isopropyl alcohol, better known as rubbing alcohol or surgical spirit.
Mix three tablespoons of Isopropyl alcohol with one quart of water in a spray bottle and apply liberally to your weeds.
As with boiling water, this works better for getting rid of weeds that grow in the cracks in your driveway or patio but may not get rid of the roots.
How to Prevent Weeds Growing in Your Garden
Applying a layer of mulch to your soil will deprive weeds of light and stop them from growing
All of the above options will prove useful in ridding your garden of existing weeds. However, as the old saying goes, an ounce of prevention is worth a pound of cure.
In other words, taking a few small measures to stop weeds from growing in the first place means you won’t have to spend as much (if any) time or energy getting rid of them further down the line.
The two most effective ways to prevent weeds from growing are:
There’s a good reason why so many professional gardeners swear by mulch:
It really is one of the most effective weed control methods out there.
Whether you opt for wood chips, straw, pine needles or any other variety, you’ll find that mulch has multiple benefits.
Organic mulches like Ameriscape’s popular Forest Cedar Mulch often attract bugs like carabid beetles and crickets which actively seek out and feed on weed seeds, creating a wonderful, natural weed-control system.
While that’s going on, the mulch itself will block out the light so that weeds won’t be able to grow.
Unlike some methods, this isn’t a one-and-done job. To really keep on top of those weeds, you’ll need to replace and replenish your mulch on a regular basis. As you’re doing so, be sure to keep your mulch layer at a consistent two-inch thickness as anything more than that will starve the soil of oxygen, ultimately killing off the plants you do want to keep.
Using Mulch With a Ground Layer
Even the best mulch in the world can only block out so much light. No matter how much you apply, a few rays of sunlight are going to slip through the cracks, so it pays to add a ground layer beneath that mulch.
If you weren’t sold on our earlier suggestion to use newspaper, then you’ll find that standard cardboard works just as well to completely smother your weeds.
Paper and cardboard are our preferred materials as they’re biodegradable, meaning you won’t have any cleanup work to do after the weeds are dead and gone. However, if you prefer, you can always invest in a roll of durable landscaping fabric like Ecogardener’s Premium Pro Garden Weed Barrier.
2: Corn Gluten Meal
Though some gardeners use it as a natural lawn fertilizer, we think corn gluten meal’s best application in the garden is as a weed-prevention tool.
A common misconception is that corn gluten meal prevents seed germination, though this isn’t exactly true.
Rather, it’s oily coating stops weeds from forming roots and thus ensures they’re unable to grow.
There are also some naysayers out there who will claim that this doesn’t actually work, though it seems to be the case that they’re using the wrong type of corn gluten meal, or even getting it mixed up with the standard cornmeal that you’d buy from a grocery store.
Cornmeal and corn gluten meal are two different things which come from the same source.
The cornmeal that you use in cooking comes from whole corn kernels but has absolutely zero impact as a herbicide.
What you need is corn gluten meal, which is a left-over byproduct of the process used to make regular cornmeal, though even then, not all corn gluten meal is created equally.
To have any effect on your garden, you need a variety that has at least 60% protein. You’ll find this in most garden centers labeled as a pre-emergent herbicide.
Since this is relatively expensive, it may be tempting to use a cheaper product like corn gluten feed, but unless it is specifically labeled as a pre-emergent herbicide, it will have little to no effect on your weeds.
How to use Corn Gluten Meal to Control Weeds
To work at its best, corn gluten meal should be applied to your soil towards the end of winter or the very start of spring in order to thwart newly germinating seeds from taking root.
There are no hard and fast rules on how much to use, and in this regard, you’re only limited by your budget.
To give you a guide, 20 lbs of cornmeal per 1,000 square feet should reduce your weeds by as much as 60%, with more obviously increasing that rate further.
After applying corn gluten meal to the soil, water immediately and then leave it to dry for at least a week as too much water will dilute the herbicidal qualities and thus negate its entire purpose.
As long as the weather remains fairly dry, corn gluten meal should produce positive results for over a month, after which it may be time to replenish your supply.
Frequently Asked Questions about Homemade Weed Killers
What is the Most Effective Natural Weed Killer
There’s no better way to permanently eliminate weeds from your garden than removing the roots by hand using a trowel or similar tool
Any number of homemade, natural solutions will work in the short term. However, as with most things in life, there’s simply no substitute for hard work.
To put it another way, the most effective way to get rid of weeds without using chemicals is to do it by hand.
Put on a sturdy pair of gardening gloves, grab a trowel or other weeding tool and get to work. You’ll find that pulling up weeds from the roots is a far more effective way of eliminating them for good, even if it is much more labor-intensive.
Is Household Bleach a Good Weed Killer?
Is it good? Yes. Is it safe? Not really.
The kind of bleach you probably have stored in your bathroom makes a deadly herbicide that will eliminate even the most stubborn of weeds.
However, it will also impact the health of your soil and potentially damage the plants that you do actually want to keep.
What’s more, after you’ve used bleach as a weed killer, the surrounding soil will be unable to support new growth of any kind for months, though that should be the least of your concerns.
Household bleach contains all kinds of poisonous chemicals which are not only harmful to your plants, but to you, your kids, and your pets as well.
In short, it’s effective, but also very dangerous. Any of the weed killer alternatives we’ve discussed above will be much safer to use while still dealing with weeds effectively.
Is Newspaper Safe to Use in the Garden?
Newspapers are much safer to use as a weed-prevention method than you might think.
Sure, once upon a time the headlines were printed using fairly toxic, petroleum-based inks. Today, however, 90% of daily newspapers in the United States (as well as countless weeklies and periodicals) are printed using safe, soy-based inks.
One way to test if a newspaper is safe to use is to rub your finger over the print. If the ink leaves a deep smudge on your finger, that likely means that it is petroleum ink. If it doesn’t, it’s likely to be non-toxic soy ink that is fine to use in the garden.
Failing that, it never hurts to contact the publisher to clarify.
Final Thought: Consider Your Future Gardening Plans Before Killing Weeds
As natural weed killer alternatives go, the salt, vinegar, and soap solution we looked at earlier works better than most. That said, it does such a good job at both killing existing weeds and preventing future ones from growing that it can also do some major long-term damage to your soil.
With that in mind, if you are thinking of using this method, ensure that you only use it in areas of your garden where you’re 100% certain that you don’t want anything to grow in future.
For example, sidewalks, pathways, and patios are ideal targets for salt-based weed killers, whereas if you’re planning to replace invasive plants with something a little more pleasing, you’ll benefit from using a method that doesn’t have the same long-lasting impact, such as using boiling water or digging out those gardening gloves and removing weeds the old fashioned way.