While salt may get rid of weeds, it doesn’t stop there! Its impact on the soil and biodiversity could make you regret this radical solution. Explanations.
Salt, the food we use to season our dishes, is above all a chemical element. In chemistry, a salt or ionic compound is a chemical compound made up of cations and anions forming an electrically neutral whole (without a net electrical charge), according to Wikipedia. It is also a powerful disinfectant, isn’t it said that you dip your finger in coarse salt if it is infected? In the garden, some people use it as a weedkiller, and that might not be the best idea! In fact, we often hear that a few pinches of salt are enough to get rid of weeds, whether in the paths, on the terrace or even in the vegetable patch. But before you turn your garden into the Dead Sea, I suggest you first understand the effects of this method on the soil and biodiversity. Spoiler alert: it’s not as harmless as it seems! We talked about it in this article, but here’s a more detailed overview.
Why does salt work so well as a weed killer?
Salt acts on plants through several well-known biological mechanisms. First, it dehydrates the cells, preventing them from absorbing water and eventually killing them. Then, it changes the chemical composition of the soil, replacing essential minerals (potassium, calcium, magnesium) with sodium ions. As a result, plants can no longer absorb the nutrients they need to survive. Finally, it causes oxidative stress on plant cells, leading to their progressive weakening. So yes, salt is an effective weed killer, but at what cost? Unlike other substances, it does not degrade easily and can remain active in the soil for a long time, eventually affecting all the plants around it.
The consequences of salt on your soil
The problem with salt is that it doesn’t just kill weeds. Once in the soil, it destroys the microorganisms essential to its fertility, modifies its structure and makes it compact, which limits its aeration and permeability. As a result, soils with too much salt become sterile and unable to accommodate new plantings. And that is not really the desired effect. Another rather perverse effect is that the salt melts like snow in the sun with the rain and watering. Thus, by seeping into the soil, it can contaminate the water table and be absorbed by nearby trees or other plants. Excessive salt accumulation in the roots can thus lead to the death of entire trees, without you having intended to target them.
What alternatives to salt are there for weeding?
If you want to get rid of weeds without ruining your soil, there are several alternatives:
- Manual weeding: certainly more tiring, but formidably effective if done regularly.
- Mulching: by covering the soil with bark, hay or cardboard, you prevent weeds from germinating.
- False sowing: water your soil, let the weeds grow and pull them out before planting.
- Thermal weeding: a special blowtorch can eliminate weeds in a few seconds.
Using a solution of coarse salt to weed is effective, but harmful to your soil. Photo credit: A. Bonazzi for NeozOne
And you? What methods do you use to keep your garden neat and tidy without harming nature? Are you interested in this subject? Feel free to give us your opinion or share your experience with us. Please report any errors in the text to us. Click here to post a comment.
