Most gardeners dread weeds in the garden. Hand-pulling is time-consuming and repetitive, but many gardeners also want to avoid using commercial products. chemical herbicides as they pose both environmental and health risks.
That said, there are some non-toxic herbicides that can be used to effectively control weeds in the garden: table salt. Although no herbicide can really be considered “harmless” in the garden (after all, its main purpose is to kill unwanted plants), salt (or sodium chloride) is a natural solution that works well on nuisance weeds.
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Can salt be used to kill weeds?
In short, salt is an effective non-toxic herbicide. However, not all salt is equal when it comes to weed control. Either iodised or non-iodised normal table salt should be used. Check the packaging to ensure that it uses sodium chloride and not magnesium sulphate (Epsom salts), rock salt or sea salt.
Salt as a herbicide should be applied with care. It can easily kill surrounding plants or leach into the soil and affect their long-term health. Too much salt can even sterilise the soil over time. Therefore, it may be more effective to treating weeds that are not surrounded by plants of interest to you in the garden, such as weeds that creep through cracks in the asphalt or pavement, or that grow between stones in the courtyard.
The chemistry of salt: how salt works to kill weeds
Salt (sodium chloride) kills weeds by dehydrating plants and disrupting the internal water balance of their cells. Since salt is soluble in water, it is most effectively applied when mixed with water, which facilitates its uptake by weeds. Sodium chloride is highly toxic to all plants, so it should be applied with caution. In general, salt is best used as a herbicide for gardening or small-scale weed control.
How to use salt as a herbicide
Salt is most effective as a herbicide when mixed with water. The recommended concentration of the salt and water mixture depends on where you are applying the herbicide. If you are applying salt to weeds in a flower bed with other plants that you do not want to kill, you should start with a weaker mixture, such as a 1:2 mixture of salt and water.
Alternatively, if you are applying salt in an area where long-term soil health is not an issue (such as between patio stones, cracks in driveways, etc.) you can make a much stronger mix, such as a 2:1 or 3:1. This amount of salt will undoubtedly affect the pH levels of the soil over time and can lead to soil sterility.
Saltwater solutions should be applied directly to the weed foliage. Avoid soaking the roots with the mixture to protect the soil and surrounding plants. Salt water can be applied with a sprayer or poured from a container. If there are other plants nearby, water them generously after applying the herbicide to the weeds to remove any salt water that may have penetrated into the surrounding soil. Salt water treatment is not recommended in confined flower beds and orchards.
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Salt versus other non-toxic herbicides
Other “non-toxic” herbicides are popular with home gardeners. Each has its own advantages and disadvantages, and no single option is a one-size-fits-all solution.
Domestic vinegars are an option, although they are less effective than horticultural vinegars containing higher concentrations of acetic acid. These vinegars, when mixed with salt and water, have the potential to control weeds well. As with the salt and water mixture, vinegar should be applied with care, as it can change the pH balance of the soil over time, affecting the growth of future plants.
Boiling water can also be used with some effectiveness. It is a great option for treating difficult weed clumps in a flower bed, as the water will have no residual effects on the soil. However, as with most herbicides, boiling water must be applied to the garden very carefully so as not to damage the plants you do not want to kill.
Surprisingly, fire is another ‘non-toxic’ weed control method used by gardeners. Fire burns emerging weeds, causing damage at the structural level. Although fire control permanently eliminate annual weedsdoes not kill the roots of more resistant weeds. perennial weeds. Flame brushcutters can be purchased online or at most garden centres or nurseries.