In fact, the idea that salt makes an excellent herbicide is both true and false. Salt kills plants very effectively, indeed all plants, but it is so toxic that I simply cannot recommend its use in most gardens.
Salting will effectively eliminate all vegetation, and do so for months, years, even decades, leaving the soil essentially barren, free of almost all life.
Is salt good or bad for plants?
Salt has a harmful influence on plants, so it is not good at all, and it also has a harmful influence on the soil: not only does it destroy the micro-organisms that live in it, but it also modifies its structure: the soil settles and loses permeability. Not to be confused with Epsom salt, which is used as a fertilizer!
Moreover, it does not degrade. It can therefore be absorbed by nearby plants and affect them. Trees in particular have root systems that are several kilometers long. When the root system absorbs salt, it will store it. Beyond a certain quantity, the tree will die.
Salt is not only harmful for undesirable people? It is just as harmful for the surrounding plants, for the life of the soil and for the soil itself.
Is it necessary to weed with salt?
How does salt weed?
Salt does not act in only one way on plants.
- It dehydrates them: the salt causes an increase in osmotic pressure in the soil, resulting in water retention in the soil. The plants then have no more possibility to hydrate themselves and end up dying.
- It disrupts their absorption of minerals contained in the soil: the ions released by the salt tend to replace the other ions contained in the soil, including the ions that are essential to plants such as potassium, calcium or magnesium. These will be washed away by rain because they are no longer fixed by the plants.
- It causes the accumulation of toxic ions.
- It leads to an important oxidative stress.
Possible symptoms of salt poisoning on plants: yellowing of leaves, chlorosis, burns, necrosis, drying of foliage, leaf curling, death of young stems…
Which salt to use for weeding?
Even though our grandparents used salt to weed, today we know that it is not without effect on the environment. Not only is it bad for plants, whose hydration and development it impairs, it is also harmful to soil life. Therefore, we strongly advise against using salt for weeding.
Weeding with fine salt is very simple: just sprinkle the unwanted weeds you want to get rid of with your kitchen salt. You can either do this on a day when it’s going to rain, or you can water after sprinkling.
Another method, just as simple: boil salt water at a rate of 200 g of salt per 1 l of water and pour it over the weeds. If it is warm or cold, it is only the salt that will act, otherwise it will be combined with the already aggressive action of the boiling water. To justify this expenditure of energy (and water!), prefer to use salted cooking water for your vegetables, pasta, rice and potatoes. The starch contained in the latter will also provide its weed-killing properties.
What dosage to weed with cooking salt? In water, you will put 20% of fine salt. For a “dry” weeding, it will depend on the surface to weed.
Snow removal salt
Weeding with de-icing salt is quite possible because it does not differ from fine salt. Snow removal salt has the advantage of being available in large packages, usually 25 kg. Like cooking salt, it is made of sodium chloride, but it is also available with magnesium or calcium chloride, which are less aggressive and therefore cannot be used for weeding.
Using coarse salt for weeding is better than using fine salt, because it is sold in larger packages and makes the operation even less expensive. As with fine salt, you can scatter it at the base of undesirable plants, or dilute it with water to spray larger areas.
The dosage of water and coarse salt for weeding is as follows: for 1 liter of water, you will need 200 g of coarse salt.
Weeding with Epsom salt is not possible, it is rather used as a fertilizer for crops! Epsom salt is composed of magnesium sulfate, and magnesium is an absolutely necessary nutrient for plants.
Salt and vinegar
Weeding with salt and vinegar is a very common “grandmother’s recipe” but it is very radical because it combines 2 substances that are harmful to plants. Vinegar is not an authorized product as a weed killer. Therefore, we do not know its impact on the environment and it is better not to use it in the garden.
What is Epsom salt?
Epsom salt is pure magnesium sulfate. For several centuries, it has been known for its numerous health benefits. It is also an indispensable ally for the garden and more particularly for the vegetable garden. Like us, plants sometimes lack the nutrients they need to thrive. Epsom salt plays the role of natural vitamins. It gives spectacular results on green plants, flowers, vegetable plants, roses, trees and even on the lawn.
Indeed, it is a natural nutrient that strengthens the roots and helps plants to absorb chlorophyll and regenerate in a very short time. The plants are stronger, fuller, their leaves do not yellow and the fruits are bigger. Epsom salt is ideal for soils low in magnesium and sulfur. A little bonus: it repels slugs.
How to use Epsom salt?
In the vegetable garden
Epsom salt promotes germination. Sprinkle about a cup of it on an area of 100 square feet and then turn the soil over before sowing the seeds. You can do the same thing before you put your plants in the ground. The salt will have the same effect as fertilizer! You can also put a large teaspoon of salt at the foot of the plants to boost the roots.
With each watering or rain, the salt will penetrate the soil. This application, once every 2 weeks, is ideal for tomatoes, peppers and even roses! It boosts their growth.
Green plants and evergreen trees
Epsom salt can be used as a foliar fertilizer (sprinkled on the leaves). Dilute a large teaspoon of salt in 1 L of water and spray the mixture on the leaves of your green plants, about once or twice a month. They will be more vigorous and greener because the salt activates photosynthesis.
Roses and shrubs particularly appreciate it. Evergreen trees such as Azaleas and Rhododendrons also love Epsom salt. Mix a tablespoon in the water and pour it on the roots every two to four weeks.
Epsom salt is ideal for keeping your lawn green. To take advantage of its benefits, apply 1.5 kg of Epsom salt to a 250 sq ft plot. This treatment is best applied in the spring.
Weeding with salt is a practice that, although effective, should not be used. This substance is harmful to the soil and to the organisms that live in it, and in addition it can be absorbed by plants that you do not want to get rid of at all!
The methods of clean weeding are many and varied and you can find your happiness, and combine them for more efficiency and comfort! But before eradicating all the plants that you have not planted in your garden, ask yourself if some of them do not have a small interest, either for you or simply for the biodiversity of your environment.