Ready mix vermicompost and epsom salts is composed of vermicompost added with magnesium sulfate. It is beneficial for all garden plants.Magnesium is an essential nutrient for plants and is necessary for the synthesis of chlorophyll, which is crucial for photosynthesis. Sulfate can also help improve the absorption of nutrients by the plant roots. If a plant’s leaves turn yellow, it can be a sign they need more sulfate. If lower leaves turn yellow they may need more magnesium.