What is a herbicide-free way to control dandelions?
Option 1: Cover driveways or walkways with tarps, cardboard, or black plastic
Sunlight is needed for photosynthesis, so covering the dandelions will eventually kill them.
Option 2: Vinegar Solution
One method that seems to work, but is not scientifically proven is a vinegar solution. The acidity of the vinegar, made more potent by the salt, “sucks the water out” to kill the dandelions, while the soap makes the mixture better adhere to the leaves. There are many different recipes available online, but it is suggested to use low salt mixtures with an organic biodegradable soap, two recipes:
More effective, more lawn kill: 1 gallon of vinegar (5% acetic acid), 1 cup of salt, and 1 tablespoon of biodegradable dish soap
Less effective, less lawn kill: 1 gallon of vinegar (5% acetic acid) and 2 tablespoons of biodegradable dish soap
The vinegar solution works best when it is applied in dry sunny conditions and may require multiple applications because there is no residual action, allowing new weeds to grow in replacement. Wait at least two weeks between applications to reduce the salinity and pH impact on the soil.
Caution: Use as a spot treatment and in small quantities only. As it may kill off healthy lawn, we suggest testing it on a small section first. As well, the salt and the vinegar can still impact the natural soil salinity and pH; therefore, it is best to use on driveways and sidewalks to limit the impact.