I received a gardening tip from Dwight in Bethlehem, PA, for a homemade organic weed killer made from white vinegar.
I have stone landscaping instead of mulch and have a few weeds coming through the weed tarp to say the least. It looked great the first full year after finishing the job, but soon after, the weeds took root. This year is a fast bloomer for the weeds in my landscaping. I just wanted to let you know that I tried using boiling hot white vinegar as a natural weed killer, and it worked great. Being careful not to hit anything but weeds, everything that I sprayed was totally dead and discolored less than 24 hours later. Getting the boiling hot white vinegar to come out of the sprayer was a challenge, but the result was better than expected. Now if I can only find out where to buy a case of vinegar, I’ll be set. It took me 2 gallons and I didn’t even get around half the house, but I am hoping that this is a more permanent weed control than what I’ve had in the past.
Thanks for your email. White vinegar is an age old solution for organic weed control. It works best mixed with some salt, lemon juice and a little dish soap, so the mixture sticks to the plant a little better. Vinegar is simply acetic acid, usually derived from decomposing apples, grain or grapes. During decomposition, the sugars in the plants are converted into alcohol and carbon dioxide through fermentation and this process creates vinegar.
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But be careful – vinegar is highly acidic – any plant you spray it on will die, and it will lower the pH of your soil for at least a few weeks, so there will be a waiting period before planting anything where you sprayed. The white vinegar is completely biodegradable, which is why it’s approved for organic agricultural use as well.
I’ve found that simply adding a few tablespoons of salt to boiling water is sufficient to kill most weeds. Whenever I see something I don’t like between the cracks in the sidewalk, I take my tea pot outside at full boil, pour it on the unwanted weeds and it cooks them almost immediately. But the white vinegar solution is great for larger, more stubborn areas with weeds. For areas where other vegetation is growing, like garden beds, I always recommend pulling weeds by hand.
It’s a lot cheaper than Roundup, and doesn’t leave toxins behind.
The white vinegar/salt solution is a highly acidic substance, so use it with caution. For weeds popping up through cracks in sidewalks and the like, it’s usually sufficient to use boiling salted water (just a small amount of salt will do – don’t go overboard with it). Add the vinegar to the solution if you have repeat offenders which don’t react to water and salt alone.
I recommend that you don’t use the vinegar solution if you need to weed a large area where you wish to plant – it’s highly caustic and may acidify your soil for longer than you’re prepared to wait. If you need to weed a large area that you want to add plants to, it’s always best to turn the soil with a shovel or rototiller and then plant what you like.