In an attempt to go organic, many articles on the use of organic materials in gardening are constantly being published on the internet these days which lay claim on their usefulness. Many of these claims, however, are not even based on scientific research. More than being useless, some of these so-called hacks can even cause problems and may even be dangerous.
One of the more popular ones that is being promoted is the use of Epsom salts in gardening. Just type in Epsom salts on your search bar and your will find loads of webpages dedicated to its use and many benefits. It is said to be the miracle “go to” for many gardeners.
From being a good fertilizer to being an all-time cure for plant diseases like chorosis and blossom end rot, Epsom salt is said to be the answer to all gardening problems. But is it? Is there any truth to all that is written about it or all of these just based on techniques used years ago which now, because of scientific research, is proven to be ineffective?
WHAT IS EPSOM SALT?
The term “salt” can actually be quite misleading because many will often think that Epsom salt is the same, if not similar, to table salt. Based on the chemical definition of a salt, Epsom salt is indeed a salt since it is a chemical compound made up of one positively charged ion, magnesium (Mg+), and one negatively charged ion, sulfate (SO4- ). However, apart from the chemical definition, Epsom salt is very different from table salt since they are composed of two completely different elements.
Therefore, the uses of table salt and Epsom are different as well. The physical appearance of Epsom salt, though, is the same as table salt since both present themselves as granules.
Since Epsom salts occur naturally, they are thought to be of good use when it comes to organic gardening. Epsom salt, many claim, is a natural pesticide and natural fertilizer. It is said to improve seed germination and the flowering potential of flowering plants. It is also said to correct problems such as chlorosis and blossom end rot. The next paragraphs attempt to discuss and clarify matters regarding these claims.
EPSOM SALT IS A VERY GOOD NATURAL FERTILIZER
In order to understand the role of Epsom salt as a fertilizer, you will have to go back to the composition of Epsom salt. As was mentioned, Epsom salt is made up of two basic elements: magnesium and sulfate. Both magnesium and sulfate, while vital to plant nutrition, are minor nutrients needed by plants. In fact in well-balanced soil, the amounts of magnesium and sulfate are already quite sufficient. Unless there is some form of magnesium deficiency in the soil, there really is no need for the addition of Epsom salt to the soil.
In fact, this may even be detrimental to the plant since excess magnesium can cause nutrient imbalance in soil which can eventually lead to problems in terms of nutrient uptake in plants.
Epsom salt will not contribute to better foliage, nor better lawn grass, since none of these require much magnesium nor sulfate for their nutritional needs.
EPSOM SALT IS A GOOD PESTICIDE
There have been many things written about how Epsom salt can serve as a deterrent to many insects and pests. Some articles will even say that Epsom salt can kill these pests that, normally, will cause a lot of headaches to you, the gardener. Go through many scientific publications and researches however and you will notice a great lack of evidence that will prove this claim. Many experiments have already been performed to prove the use of Epsom salt as a pesticide or insecticide. So far, positive results are still much needed in order for this to be conclusive.
EPSOM SALT KILLS WEEDS
Many pages promote the use of Epsom salt as weed killers. There is , again, no scientific proof to this claim. Commercially available weed killers , when sprayed on weeds, seep through the soil and go directly to the roots. This is taken up by the weeds resulting in these getting poisoned . Epsom salt, however, stays on the leaf surfaces. They do not penetrate into the roots rendering Epsom salt to be ineffective.
EPSOM SALT IMPROVES AND AIDS IN SEED GERMINATION
Seed germination is a very natural process in plants and most factors which contribute to its speed and occurrence highly rely on nutrients found in the seed itself. The amount of nutrients in the seed is more than enough to trigger germination. Nutrients outside the seed barely affect seed germination, if they do affect the process of germination at all.
EPSOM SALT WILL REVERSE CHLOROSIS
Chlorosis is a disease in plants which results in the leaves turning yellow. This is caused by a lack of chlorophyll, a substance needed by plants in order to initiate photosynthesis. While it is true that magnesium is one of the elements that comprise chlorophyll, it is not true that a lack of magnesium will lead to chlorosis.
Chlorosis is a condition that is indeed caused by nutrient deficiency in plants. However, the nutrient in question is iron and not magnesium. A lack or iron is what causes this condition. Therefore, in order to correct this condition, it is recommended that iron supplements be added to the soil to increase iron uptake. Addition of Epsom salt in the soil will have no effect in plants with chlorosis and this will not reverse the said condition.
EPSOM SALT SOLVES BLOSSOM END ROT
Blossom end rot is a condition which affects fruit-bearing plants like tomatoes, cucumbers, eggplants and the like. It starts off as a blackish spot at the bottom of the fruit which slowly spreads and leads to an early rotting of the fruit even before harvesting.
This condition is usually caused by erratic changes in moisture in the soil. It can also be caused by excess salts in the soil due to an imbalance of nutrients.
One element and nutrient that is needed by plants is calcium. In fact, calcium levels in plants should be at least ten times higher than that of magnesium. When magnesium levels are high, they tend to compete with calcium resulting in the lessened uptake of calcium by the plant.
As for moisture control, instead of the addition of Epsom salt, it is recommended that a good layer of mulch be added on top of the soil so that moisture levels are kept constant. Regular irrigation will also help in keeping the soil moist.
EPSOM SALT ENCOURAGES FLOWERING POTENTIAL
The amount of minor nutrients in soil have no effect on the flowering potential of plants. Factors that will affect flowering potential are temperature and water. Different flowering plants will have different temperature and climate requirements. It is best to check what your plant will require.
The use of organic fertilizers which contain nutrients other than magnesium and sulfate will contribute more to the flowering potential of plants since they will be more complete in terms of the nutrients that they will be able to provide.
The use of Epsom salts in gardening is limited to soil which is greatly lacking in magnesium. Soil testing, however, needs to be done in order to determine whether or not there is a deficiency of this in the soil being used. Other than that, excess magnesium due to the addition of Epsom salts may prove to be more detrimental to plants and may, in fact, even become a soil contaminant which may cause future problems.