Asked May 12, 2017, 9:06 AM EDT

Can I use magnesium sulfate (Epsom salts ) bath water to water plants? Magnesium chloride? Dilution ratio?

Montgomery County Maryland

3 Responses

Thank you for your question. Are you looking to correct a nutrient deficiency of a particular type of plant? Or are you asking if it is safe to dispose of the bathwater on plants? We would need a little more information in order to assist you.

Adding Epsom salts (magnesium sulfate) to tomato plants, for example, is not recommended unless a soil test indicates there is a magnesium deficiency. Otherwise, adding additional magnesium can inhibit the plant's uptake of calcium, which would cause other problems. Please tell us more about what you hope to achieve and what the plant is, and we will be happy to assist you.


I heard that magnesium is good for plants and wondered if I added a cup of my foot bath water to my watering can would that we a good thing.

You still didn't mention what plant.
If it were houseplants, the general dilution is just one teaspoon per gallon of water.

It is not recommended that you add it to tomatoes unless your professional soil analysis shows a pH problem or magnesium deficit.