How to Use Epsom Salts for Healthier Plants and Flowers

Hard work and dedication go into creating a garden full of healthy plants. When a plant experiences a nutrient deficiency or isn't producing the blooms, crops, or foliage it should, it can cause concern. However, there is a natural remedy equipped with essential minerals that can help plants bounce back and grow to their full potential.

Epsom salt, or magnesium sulfate, is a common household item that gardeners use to boost the health of their plants. A chemical compound consisting of magnesium, sulfate, and oxygen, when applied correctly, Epsom salt has been shown to increase bloom size, promote lush green foliage, enhance seed germination, and improve fruit production in plants. 

"Using Epsom salt in your garden can provide essential nutrients to your plants, promoting their growth and overall health,” says Cameron DePaola, a master gardener and landscape designer. "Additionally, Epsom salt helps plants grow stronger and more vibrant by improving nutrient absorption, and can also alleviate certain plant ailments, leading to overall healthier and more vigorous growth."

Although Epsom salt is a great way to keep your garden healthy and address nutrient deficiencies, proper plant assessment and application methods are required. We asked experts to share everything you need to know about using this garden helper.

Why Use Epson Salts for Plants?

The science behind why Epsom salt brings out the best in garden plants comes down to its ability to provide them with two essential nutrients: magnesium and sulfur. "Magnesium is crucial for chlorophyll production, which is responsible for photosynthesis," says DePaola. "It also activates enzymes involved in plant growth and nutrient uptake."

Sulfur is essential for protein synthesis and overall plant development. "When Epsom salt is dissolved in water and applied to the soil, plants can absorb these nutrients through their roots," says DePaola. This leads to improved chlorophyll production, better nutrient uptake, and overall healthier plant growth.

"However, it is important to use Epsom salt sparingly and as directed to avoid negatively impacting soil pH levels and triggering other plant deficiencies," DePaola says.

Plants That Benefit from Epsom Salts

Many plants can benefit from the use of Epsom salt allowing you to enjoy a thriving garden. From brighter blooms to abundant food production, these plants love Epsom salt.

• Roses: Epsom salt encourages healthy blooms and greener foliage.
• Tomatoes: Epsom salt helps prevent magnesium deficiency and blossom end rot in tomatoes.
• Peppers: Epsom salt promotes strong root development and fruit production in peppers.
• Citrus trees: Epsom salt aids in fruit production and prevents the yellowing of leaves in citrus trees.
• Houseplants: Many houseplants benefit from Epsom salt to support overall growth and health.
• Lawns: Epsom salt can improve the green color and health of lawns.
  

How to Apply Epsom Salt to Your Plants

Epsom can be applied as a drench (watered into the soil) or a foliar (leaf spray). "Before applying Epsom salt, it is recommended to do a soil test to determine the specific nutrient needs of your plants," says DePaola. Soil test kits are readily available at local Cooperative Extensions, garden centers, or universities. If the test results show there is a need for the nutrients in Epsom salt, Depaola shows you the best way to apply the solution to your plants.

Applying Epsom Salt to Your Flowers

• Solution: Dissolve 1 tablespoon of Epsom salt in 1 gallon of water.
• How much to use: Apply the Epsom salt solution once a month during the growing season.
• Where/how to apply: Water the base of the plant with the Epsom salt solution, avoiding wetting the leaves.
• When to apply: Start applying Epsom salt in the spring once new growth appears and continue throughout the growing season.
  

Applying Epsom Salts to Your Vegetables

• Solution: Dissolve 1 to 2 tablespoons of Epsom salt in 1 gallon of water.
• How much to use: Apply the Epsom salt solution every two to four weeks during the growing season.
• Where/how to apply: Water the base of the plants with the Epsom salt solution, ensuring the roots can absorb the nutrients. You can also use it as a foliar spray, applying directly onto the foliage every four to six weeks.
• When to apply: Begin applying Epsom salt before planting and continue throughout the growing season every three to six weeks.

Applying Epsom Salt to Trees

• Solution: Dissolve 2 tablespoons of Epsom salt in 1 gallon of water.
• How much to use: Apply the Epsom salt solution around the base of the tree's drip line.
• Where/how to apply: Pour the Epsom salt solution around the tree, avoiding direct contact with the trunk.
• When to apply: Apply Epsom salt in the early spring before new growth emerges and again in the fall.

How Often Epsom Salt Should Be Used on Plants

 Although you only want to use Epsom salt on plants that need it (and after the soil has been tested), you can use Epsom salt on your plants in the garden once every four to six weeks. "This will ensure you’re not overdoing it and end up causing damage," says Emily Scott, owner of Scott Farm in Maine. For potted plants, Scott recommends applying the Epsom salt solution once per month.

When planting a magnesium-loving plant in your garden, such as roses, Scott recommends adding a light sprinkle of Epsom salt to the soil before planting it into the garden.

Expert Tips for Using Epsom Salts in Your Garden

Our experts share important tips to keep your Epsom salt journey smooth and successful.

• Morning Foliar Application: Apply the Epsom salt solution in the morning to allow sufficient time for absorption and to avoid potential leaf burn.
• Avoid Overuse: Excessive use of Epsom salt can harm plants; stick to recommended amounts.
• Monitor Plant Health: Observe plants for any signs of distress or over-fertilization and adjust usage accordingly.
• When Foliar Spraying: When foliar spraying, be sure to spray from the bottom of the plant upwards, spraying the undersides of the leaves.