Epsom salts (for plants) - Ask Extension
Lots of people are recommending Epsom salts for houseplants, and Thanksgiving/Christmas/Easter cactus plants, (1 teaspoon per gallon of water?) Also a...
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Epsom salts (for plants) #789177
Asked May 03, 2022, 10:23 PM EDT
Lots of people are recommending Epsom salts for houseplants, and Thanksgiving/Christmas/Easter cactus plants, (1 teaspoon per gallon of water?) Also added in soil for outside gardens. Many people are bragging about how their plants really benefitted. What does MSU say about this? Thanks!
Wayne County Michigan
Expert Response
Hello
Unless your soil or growing media is low in magnesium, do not apply Epsom salts. Use a reliable lab to test your soil or media.
MSU Soil lab is one you may use. See this article on how to take a soil test and how to purchase a Soil Test kit- https://www.canr.msu.edu/uploads/236/21432/Soil_Test.pdf
Here are research-based articles from different Extensions on using Epsom salt for plants-
https://s3.wp.wsu.edu/uploads/sites/403/2015/03/epsom-salts.pdf
https://extension.unl.edu/statewide/platte/Horticulture/Epsom%20Salts%20and%20Vegetable%20Gardens.pdf
https://extension.umn.edu/manage-soil-nutrients/coffee-grounds-eggshells-epsom-salts
Using Epsom salt when not needed can actually harm plants. The excess magnesium can block the plant from being able to take up the needed amount of calcium.
Also, most Michigan soils are naturally high in Magnesium, and do not need more. In some parts of the country the soils are naturally low in Magnesium.
Perhaps the anecdotal evidence you read about was for soilless mixes that had no added fertilizers.
In the future, to find reliable, research based garden articles, search the internet using a suffix of “site:edu”
For example—
Epsom salt for plants site:edu
This will return mostly Extension and University site articles, which are always research based( along with a few advertising sites, which the search engine always gives us to help pay for our use of it!)
I hope this is helpful.
Unless your soil or growing media is low in magnesium, do not apply Epsom salts. Use a reliable lab to test your soil or media.
MSU Soil lab is one you may use. See this article on how to take a soil test and how to purchase a Soil Test kit- https://www.canr.msu.edu/uploads/236/21432/Soil_Test.pdf
Here are research-based articles from different Extensions on using Epsom salt for plants-
https://s3.wp.wsu.edu/uploads/sites/403/2015/03/epsom-salts.pdf
https://extension.unl.edu/statewide/platte/Horticulture/Epsom%20Salts%20and%20Vegetable%20Gardens.pdf
https://extension.umn.edu/manage-soil-nutrients/coffee-grounds-eggshells-epsom-salts
Using Epsom salt when not needed can actually harm plants. The excess magnesium can block the plant from being able to take up the needed amount of calcium.
Also, most Michigan soils are naturally high in Magnesium, and do not need more. In some parts of the country the soils are naturally low in Magnesium.
Perhaps the anecdotal evidence you read about was for soilless mixes that had no added fertilizers.
In the future, to find reliable, research based garden articles, search the internet using a suffix of “site:edu”
For example—
Epsom salt for plants site:edu
This will return mostly Extension and University site articles, which are always research based( along with a few advertising sites, which the search engine always gives us to help pay for our use of it!)
I hope this is helpful.
