How Often Should you Put Epsom Salt on Plants

If you are new to gardening, chances are you’ve spent tons of time looking for ways to make your garden better. And the odds are high you’ve heard lots about Epsom salts and how they make plants flourish. The main question is; how often should you put Epsom salt on plants?

Many gardeners that grow crops such as tomatoes and roses swear by Epsom salts. The phrase ‘the best-kept secret’ is even sometimes thrown liberally around to validate the efficacy of Epsom salts. This ‘secret’. though, has been around for several generations helping people grow healthy plants.

The compound is named after Epsom, the town in England where it was discovered in the 17th century. Its main components are magnesium (10%)and sulfate (13%) with a bit of water in the crystals. Magnesium and sulfate, in the right amounts, are two nutrients essential to plant growth and development.

That the compound is important to plants is not in doubt considering the volume of evidence over the years. What might pose a problem is how often you should put Epsom salts on plants, and of course, the quantity during each application. This article would throw more light on these and other aspects related to the use of the compound on plants and the soil.

8 Benefits and Uses  Epsom Salts

  1. Boosts seed germination

Studies have shown that magnesium, an important component of Epsom salts, is known to strengthen the cell walls of seeds. This aids better growth as it provides increased energy and a sturdy foundation for young plants.

  1. Faster nutrient adsorption

The magnesium-sulfate combo in Epsom salts does a god job of ensuring plant cells utilize key minerals such as nitrogen, sulfur, and phosphorus faster and more efficiently.

In plants drenched with an optimal solution of Epsom salts twice a month, thicker foliage and larger vegetables are some of the visible outcomes.

  1. For transplanting tender plants

During transplanting, tender plants can experience what ‘root shock’ typified by the discoloration of the plants and wilting. But applying a solution of Epsom salts to the roots of the tender pants before transplanting them can prevent this from occurring.

  1. Natural pests deterrent

Like plain table salt, it can kill or deter unwanted snails, voles, and bugs by dehydration.

When used to control pests in general, the recommended solution is a cup of Epsom salts per one gallon of water. But for the control of snails and slugs, sprinkling the Epsom salts crystals around the garden and base of the plants is all that it takes.

  1. Adds essential micronutrients

Magnesium and sulfur are two plant micronutrients in Epsom salts that are essential for the growth of certain plants especially in soil that is deficient in these two nutrients.

While some leafy plants would perform brilliantly even with low magnesium and sulfur levels, others won’t thrive. This distinction is important to prevent misuse of the compound. So for crops such as peppers, roses, and tomatoes, an increased level of magnesium via Epsom salts would help them thrive.

  1. Aids photosynthesis

Plants make use of magnesium for the creation of chlorophyll, a vital compound during photosynthesis. The process of making food and energy by plants is controlled by photosynthesis.

Primarily though, by helping in the synthesis of chlorophyll, Epsom salts are implicated in the production of greener and healthier plant leaves. In essence, adding the right amount of Epsom salts prevent or resolve discoloration of garden plants.

  1. Address nutrient imbalance in soils

In certain types of soils, all that is needed to resolve magnesium deficiency is to add Epsom salts to it. For instance, some soils have very low magnesium levels after years of growing magnesium-guzzlers such as tomatoes.

The first course of action is to ensure that the poor performance of the crops is as a result of magnesium deficiency by testing samples of the soil in a lab.

  1. Soil pH regulation

Many vegetables and plants would struggle to grow in soils with a pH of more than 7.5. One way to reduce the pH is to work Epsom salts into the soil. Over time, this would gradually lower the pH to levels that are optimal for plant growth. After treatment, the soil should be tested again to ensure it is at the correct pH level before planting starts.

How Often Should You Put Epsom Salts On Plants

There are various ways of using Epsom salts on plants or in the garden. How often it’s used typically depends on how you want to apply it, the nature of the plants, and the purpose of applying the compound. In essence, there is no one-size-fits-all model of Epsom salts usage.

The following sections below would outline several of the common ways Epsom salts can be used and the frequency of application.

As a general supplement in garden and houseplants

Sometimes, there are no specific reasons to use it except as a general supplement to make plants and the soil healthier. In cases like this, make an Epsom salts/water solution by adding 2 tablespoons of the crystals to one gallon of water and mix thoroughly (if you want more solution, simply stay true to the Epsom salts – water ratio).

Use this solution on the plants or garden once a month.

If you want to increase the frequency of watering the plants with the Epsom salt solution to once a week, you’ll need to reduce the concentration to 1 tablespoon per one gallon of water.

Replenishing sulfur in the soil

If you want to replenish the sulfur lost during germination, use a solution compromising 1 tablespoon of Epsom salts in a gallon of water and to drench the soil. For best results, you do this after the seeds have sprouted; you don’t have to reapply the solution again.

A different method is to add a tablespoon of the Epsom salt crystals in the hole before planting your seeds. This is done just once.


If the plan is to boost the flavor of your crops during the growing season, you could apply Epsom salt solution to the roots of nut trees, fruits, berry patches, and grapevines liberally every month while the plants are growing.

Use a 1 teaspoon to 1 gallon of water ratio for the solution.

A different method to bypass the use of a solution is to apply 2 tablespoons of Epsom salts crystals per 9-foot of soil on the root bed three times a year.

Tomatoes, peppers, and sweet potatoes

These crops thrive especially well in magnesium-rich soils. You could adopt a two-prong approach to get the best.

Before planting the seeds, add one or a couple of tablespoons of Epsom salts to the holes. Then, during the growing season, a foliar spray of Epsom salts solution once a month is recommended for the best results.

Here, the solution is made by adding 2 tablespoons of the crystals to one gallon of water.

For Houseplants

Due to its neutral pH, Epsom salts are wonderful to use on houseplants included those planted in pots.

2 tablespoons of the crystals mixed in one gallon of water and sprayed on the leaves for maximum adsorption would boost the plants’ nutrient intake. This can be done once every month.

In place of a solution, the crystals can be added directly to the soil to achieve the same purpose. Here, simply add 1 teaspoon of the dry salt for every foot of plant height once a month.

For Roses

Epsom salts can enhance the production of bountiful roses. This can be done before and after planting the rose bush and during the growing season too.

In the ‘before’ phase, simply add a tablespoon of the salt to the bottom of the hole before planting the rose.

For growing or established rose plants, mix a tablespoon of the solvent to a gallon of water and spray the foliage with the solution in spring when the plants begin to leave. Repeat this when the plants begin to flower.

A different technique to encourage new growth and flowering is to add a tablespoon per foot of rose plant height twice a month: preferably, at an interval of two weeks


Shrubs like rhododendron, evergreens, and azaleas can also benefit from the Epsom salt treatment once a month.  Apply a tablespoon of the salt per 9 sure feet.

Before Using Epsom Salts…

Not all soils and plants require extra nutrients. Some soils are perfectly okay just the way they are and adding Epsom salt does more harm than good.

The rule of thumb is to have the soil tested to determine the magnesium levels in it. Only if the result of the test shows that the soil is low on magnesium can the use of Epsom salts be greenlighted.

That said, many plants like leafy vegetables and beans thrive happily in soils with low levels of magnesium.

Another factor to consider is the pH level of the soil. While Epsom salt is perfect in lowering the pH of alkaline soils to suitable levels, acidic soils would require a different form of treatment because Epsom salt would only make the soil even more acidic.


Epsom salt, the natural mineral made from hydrated sulfate and magnesium, provides nutrients that are essential to the growth and development of plants. When used properly, they provide an easy way to nourish plants and soils.

However, there are cases when the use of Epsom salts can be harmful to soils and even plants. For instance, since plants need just small amounts of nutrients to grow, it is not a good idea to drench the plants with too much Epsom salts solution.

No matter what though,  the soli must be tested to determine it is deficient in magnesium before application. In any case, using Epsom salts on soil that is too acidic would be detrimental to the plants. But when all the conditions are right, it is easy to understand why some folks label it gardening’s best-kept secret.