How Epsom Salts Can Help Your Roses

After a hard day of weeding your garden, a good long soak in an Epsom-salt bath can soothe your aching muscles. But did you know that Epsom salts can give your roses a boost, too? It all comes down to the salts' chemical components.

The Science

Epsom salts are comprised of magnesium sulfate which, along with sulfur, occurs naturally in garden soil. Both are important secondary nutrients for plants. Magnesium is necessary for plants to generate chlorophyll, which plays an important part in photosynthesis (the pivotal process in which plants turn light energy into chemical energy). It also helps plants absorb phosphorus, which is essential for plant growth and hearty blooms. That all means that Epsom salts will help your plants reach their full potential.

The Technique

Every spring, Martha gives her roses a generous scoop—1/2 to 3/4-cup—of Epsom salts by sprinkling it in a ring around the perimeter of her rose bushes. While this is a quick and efficient technique to ensure your plants take in the salt, you can also mix them into the soil with a cultivator so they can soak it up through their roots.

A good way to measure the amount your plants will need is to give them one teaspoon of Epsom salts for each foot of the plant's height. In general, coarse, sandy soils are prone to lacking magnesium and yellowing leaves are a sign that your plant is suffering from a deficiency. If you detect this color change, try giving your plants an Epsom-salt bath with a sprayer. Make sure you do this on a cool day, at an hour when the sun isn't too strong for the best results.