Epsom salt helps improve flower blooming and enhances a plant's green color. ... It can even help plants grow bushier. Epsom salt is made up of hydrated magnesium sulfate (magnesium and sulfur), which is important to healthy plant growth.
You simply mix in the required amount of Epsom salt with water and spray it on the leaves of a plant. Ideally, do this in as new leaves are emerging, and again after blooming. Epsom salts can also be added to water and used as a soil drench, watering the plant at the soil level.
Epsom salts are pH neutral and gentle on plants, including potted houseplants. To boost nutrient intake, mix two tablespoons of Epsom salts with one gallon of water and spray onto leaves, rather than onto the roots, for maximum absorption.
Excessive levels of magnesium sulfate can cause salt injury to plants. Unnecessary use of Epsom salt will not result in better plant growth but can actually make growth worse.