Worms and Flowers

Epsom Salts as a Plant Supplement

Posted in Garden, How To by Lzyjo on March 24, 2009

The little carton of Epsom salts in your medicine cabinet can used for more than sprained ankles, it can also be used in the garden, much to the benefit of your plants. Epsom Salts will make your plants grow lush green foliage and can even bring them to bloom quicker than they would on their own.

How does it work? The chemical name for Epsom Salts is Magnesium sulfate, or MgSO4, which means there is one magnesium atom attached to every four Sulfuric Acid (sulfate) atoms. Sulfuric acid has to power to break down metals, so when it is combined with Magnesium it forms the compound salt MgSO4.

Magnesium is a key element in the center of Chlorophyll molecules. Without enough magnesium, the plant can’t produce chlorophyll (green pigment) needed to photosynthesize light into energy and food. Magnesium can be depleted in soil, especially in containers growing magnesium-hungry plants. A magnesium deficiency can be identified by yellowing of the leaves, while the veins remain green. Epsom Salts are also highly water soluble, making it readily available for plants to use.

Isn’t Salt bad for soil? Unlike table salt, Sodium Chloride, Epsom Salts does not contain sodium, which can build up in pots even from the content in tap water, thus inhibiting growth.

Commercial fertilizers all contain NPK numbers, showing the value of the Macronutrients Nitrogen, Phosphorus, and Potassium, the most plentiful nutrients available in the soil. According to Liebig’s Law of the Miminum, plants require fourteen essential nutrients to reach their full potential. The Law states that the ultimate yield cannot be produced by increasing the most plentiful nutrients, only by increasing the scarcest.  In addition to N, P, and K, plants require the macronutrients sulfur, calcium, and magnesium, as well as, the micronutrients, Chlorine, Boron, Iron, Manganese, Zinc, Copper, Nickel, and Molybdenum, a metal necessary for nitrogen fixation.

Personally, I have noticed incredible results in just days after application. I use 1 Tsp of Epsom Salts per Gallon of water. I use it monthly on my plumerias, during the growing season, and I have also had great results on citruses, which seem to crave the extra magnesium,  especially when grown in pots. I don’t use it on everything, all the time, only on things that seem to need a little extra help. Here is a before and after of my tangerine seedlings that were struggling before they received Epsom Salts.


The Epsom Salts Industry Council website recommends using it on rose bushes, (maybe I should take some of my own advice here.) tomatoes, and trees, claiming it helps plants to absorb more nitrogen and phosphorus. One warning, the site mentions that sage is one of the few plants that does not have a good reaction to Epsom Salts.

So have fun, get your Epsom salts on, your plants will love you for it and don’t forget it’s great for sore muscles after a hard day’s gardening!

To learn more, check with Wikipedia

Plant Nutrition

Epsom Salts

7 Responses

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  1. Darla said, on March 24, 2009 at 11:56 AM

    I knew it was great for some palm trees. I will be using this TODAY on my oh so sickly roses. Thanks!!

  2. ourfriendben said, on March 24, 2009 at 12:44 PM

    Great post, lzyjo! And yes, Epsom salts’ greatest renown is their use on rose bushes, so, ahem, why not give them a try? Not that they can make up for shade, but can’t hurt, might help…

  3. lzyjo said, on March 24, 2009 at 2:22 PM

    I just put some on my roses too. Hope it helps. Thanks for stopping by!

  4. lzyjo said, on March 24, 2009 at 2:23 PM

    I just put some on them. I hope it works. Like you said, it can’t hurt!

  5. Denise said, on March 27, 2009 at 1:40 PM

    Congrats on the new calf! How adorable!
    Also, I never thought of pouring boiling water on weeds. I’ll have to try it!

  6. lzyjo said, on March 28, 2009 at 9:07 AM

    Oh, he’s not ours. He’s the landlord’s. There are a lot of new calves at this time of year.
    It’s nice not to worry about the dog eating with weed killer. Thanks for stopping by.

  7. Bill in Detroit said, on December 12, 2010 at 10:48 PM

    Stuff works well on lawns, too. So far as supplying the gazillion micronutrients, a drink of compost tea works wonders, too.

    You sound like you know what you are talking about and I am looking for guest bloggers. If this sounds like a good idea to you, click the link and look around. — Bill

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