Can you use Epsom salts as a magnesium sulfate treatment for plants?
Yes, Epsom salt can be used as a magnesium sulfate treatment for your plants. Epsom salt is a form of magnesium sulfate that is highly soluble in water. This means it can be easily fed to your plants by foliar or root applications. Besides being highly soluble in water, Epsom salt also has a relatively neutral pH compared to other magnesium sources, which makes it compatible with horticultural applications.
For foliar applications, start with 1 tbsp. per gal. of water. For root applications, use 2 tbsp. per gal. of water. Allow the Epsom salt to dissolve before feeding the concoction to your plants.
For plants showing signs of a magnesium deficiency, it is recommended to use a foliar application, because plants can absorb nutrients more quickly through their leaves than their roots.