Epsom salt for gardening

Experts recommend using Epsom salt in the garden to prep your soil for planting and for specific plants, including peppers, tomatoes, fruit and roses. Epsom salt can also help with house plants, lawns, trees and shrubs. Learn more about why Epsom salt works and how to use it in your garden below.


Why is Epsom salt good for plants?

Studies show that magnesium and sulfur, two naturally occurring minerals that are major components of Epsom salt, may help plants grow greener with higher yields and more blooms. Magnesium creates an environment conducive to growth by helping seeds to germinate, increasing chlorophyll production and improving phosphorus and nitrogen uptake. Sulfur is also a key element in plant growth, helping produce vitamins.

Tests by the National Gardening Association show that Epsom salt helps produce more flowers and makes pepper plants grow larger. In addition, experts say Epsom salt reduces the total amount of fertilizer needed − and makes the fertilizer used more effective.


How do I know if my plants need Epsom salt?

We recommend working with county extension agents to test your soil before planting by sending a sample. This should be done every one to three years, depending on the cost. If there are problems with plants, county extension agents can also ask smart questions to help with a diagnosis. Here’s how to find your nearest extension agent.


How to garden with Epsom salt

Here are some expert suggestions to help provide nutrients for your garden using Epsom salt. Look at the most popular uses below. Learn more from a Cornell University professor in this article, 6 Ways to Use Epsom Salt in the Garden.


Garden start-up

  1. Sprinkle 1 cup of Epsom salt over every 100 square feet of soil.
  2. Mix into the soil before planting.

Take Note! Do not add Epsom salt to the soil where you grow sage. This herb is one of the few plants that doesn’t like Epsom salt.



Fertilizer can cause salt buildup in soil. Epsom salt helps separate fertilizer bound to the soil, making the nutrients more available to the plants. Commercial growers say it reduces the total amount of fertilizer you need and makes the fertilizer you use more effective. Some growers swear that the use of Epsom salt as a secondary nutrient makes their fruit sweeter. Here’s how to use it:

  1. For every 500 square feet of soil, mix ¼ cup Epsom salt with water.
  2. Apply the mixture when you irrigate your plants.


House plants

  1. Dilute 2 tbsp. Epsom salt in 1 gallon of water.
  2. Use mixture to feed house plants monthly.



  1. Apply 3 pounds of Epsom salt for every 1,250 square feet of lawn.
  2. Apply with a spreader or dilute the Epsom salt in water and use a sprayer.



  1. Dilute 1 tbsp. of Epsom salt in 1 gallon of water.
  2. Spray your peppers at bloom time.
  3. Ten days later, repeat the foliar spray again.



  1. Dilute ½ cup Epsom salt in 1 gallon of water and soak unplanted rose bushes in mixture to help roots recover.
  2. Add 1 tbsp. Epsom salt to each hole at planting time.
  3. Scratch ½ cup Epsom salt into the soil at the plant base to encourage flowering canes and healthy new basal cane growth.
  4. Dilute 1 tbsp. Epsom salt in 1 gallon of water per foot of plant height and spray roses with solution weekly to help discourage pests.

Learn more about growing roses with Epsom salt from master gardener Linda Cobb.


Shrubs (evergreens, azaleas, rhododendron)

  1. Dilute 1 tbsp. of Epsom salt in water for every 9 square feet.
  2. Apply to the root zone every 2 to 4 weeks.



  1. Dilute 1 tbsp. Epsom salt in water for every foot of plant height per plant.
  2. Apply every 2 weeks.



  1. Dilute 2 tbsp. of Epsom salt in water for every 9 square feet.
  2. Apply to the root zone 3 times each year.