Epsom Salt, Gardenias and Roses

Epsom Salt is Magnesium Sulfate, a salt of the elements Magnesium and Sulfur, MgSO4. It has medicinal uses as well as being used as a garden chemical. Most medical uses are best discussed with your doctor.

A soak in bath salts containing Epsom Salt after a hard day in the garden is soothing, eases sore muscles and aids sleep. Maybe it’s the combination of warm water and minerals. I buy an over the counter soak that contains other minerals in addition to Epsom Salt. (Consult your doctor if you have medical conditions such as high blood pressure, heart disease or diabetes before using mineral soaks. My friend Ellie got a rash from using the OTC soak in greater than recommended amount.)

Epsom Salt is commonly used to encourage Gardenias. They need magnesium for increasing phosphorous uptake for ‘strong bones.’ The Sulfur makes the soil more acid. Sometimes gardeners will advise to use Epsom Salt when gardenia leaves turn yellow. I’ve learned from observation that yellowing may not indicate a systemic problem. At certain times of the year, gardenias will drop leaves and new leaves form. Drought may also cause yellow leaves.

Magnesium is part of the chlorophyll in all green plants and essential for photosynthesis. It also helps activate many plant enzymes needed for growth.
Soil minerals, organic material, fertilizers, and dolomitic limestone are sources of magnesium for plants.

Sulphur helps in chlorophyll formation, improves root growth and seed production, and helps with vigorous plant growth and resistance to cold.
Sulfur may be supplied to the soil from rainwater. It is also added in some fertilizers as an impurity, especially the lower grade fertilizers. The use of gypsum also increases soil sulfur levels.

Roses are going dormant now — some of us may have to force dormancy later. Gardenias remain evergreen in winter in my climate but receive no fertilizer until spring.

Some Rosarians add Epsom Salt to a combination known as ‘Hooker’s Formula’ to fertilize their roses for the first time in spring. The internet abounds with suggested amounts to apply to roses, evergreens, tomato plants and others. The Epsom salt carton even gives suggested dosing for plants. As with any other chemical, follow directions carefully and remember that extra is not better. Consulting with local rose growers and Extension agents is advised.

Peace Rose is more colorful in spring; late fall it blooms pale yellow.

Epsom Salt even has its own web site: Epsom Salt Council

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  1. Sophia Moore

     /  March 24, 2012

    I just googled Epsom salt and gardenias and came upon this blog. My mum, who died a couple of years ago at age 92, always used Epsom salt on her Daphnies and gardenias when their leaves started to turn yellow. Glad I found this page and learned about the roses, peppers and tomatoes as well. Great stuff.

  2. Nell Jean

     /  February 18, 2012

    Reblogged this on Secrets of a Seed Scatterer.

  3. Hmmm, haven’t heard of using Epsom Salts for my roses. Mine had a banner year anyway, so I think I’m doing alright with them. I swear by the Starbucks coffee grounds I collect when I visit. Some stores have it sitting out front in baskets, sometimes you just ask them. Several of my roses topped out at 8 to 10 feet tall, with blooms up that high!

  4. Helen

     /  November 16, 2009

    Epsom salts are bought by the jugful at our house, as we're competitive walkers… now I'll have to save some for the garden.

  5. Nell Jean

     /  November 16, 2009

    Thank you to everybody who visited. Some of you learned a new tip, some of you confirmed that Epsom Salt is popular.

    I wish you could all grow gardenias. They used to be a popular florist's flower for romantic corsages — I haven't seen a gardenia corsage in years.

  6. Amy

     /  November 15, 2009

    Interesting post and I didn't know about epsom salts for roses. I wish I had gardenias. They smell so wonderful!

  7. sanddune

     /  November 14, 2009

    Your Gardenia looks fantastic as does your photography. The sand here in South Florida in which I grow some Gardenia is very alkaline. I'm going to try your epson salt trick on mine to make it more acidic. Great post, I learned something new, thanks.

  8. Ellie Mae's Cottage

     /  November 13, 2009

    I use epsom salt in the veggie garden on tomatoes and peppers. They love it. Never heard it used with roses, but I'll have to try it. Thanks for the info.

  9. Susan

     /  November 13, 2009

    Thanks for the education on epsom salts. It's obvious that your gardenias react well to it.

  10. donna

     /  November 13, 2009

    Another good gardening tip to add to my long list of other tips. Now, if I'd just remember to look at the list once in a while.

  11. Autumn Belle

     /  November 13, 2009

    Wow, this white gardenia is so very very beautiful. I can smell it here from my computer screen. Thanks for the great tips too.

  12. Catherine@AGardenerinProgress

     /  November 13, 2009

    I've heard about Epsom salts used on roses, but never have tried them. I guess you could soak your roses feet in them and soak your feet later after finishing the gardening.

  13. janie

     /  November 12, 2009

    I knew about the roses, but not about the gardenias. My gardenias have bloomed since last February. They were in the greenhouse and started to bloom, and just continued and continued. They are in big pots now.

    Is it a sign of some impending doom? Global warming? Global coolimg? Atrophy on Wall Street?

    What? Why? !!!
    ( I am secretly very happy about it, as long as it doesn't hurt my gardenias, which it doesn't seem to have done.

  14. Mary Delle

     /  November 12, 2009

    Epsom with gardenias. I will try that next spring. Wonderful post on the uses of epsom salt.

  15. Elephant's Eye

     /  November 12, 2009

    How fascinating. Our Peace is faded by the sun in summer. But darker in autumn. Germiston Gold is a disappointing straw yellow in summer, but earns its name in autumn.

  16. Grace Peterson

     /  November 12, 2009

    Hi Nell~~ I'm a user of Epsom salts but like all of my soil enhancement exercises, it's hit and miss. The plants seem to be forgiving.

  17. azplantlady

     /  November 12, 2009

    Hello Nell Jean,

    Great info! I have always used Epsom Salts for my roses. They help my leaves stay green and glossy.

  18. tina

     /  November 12, 2009

    I just found a bag this morning. I need to go spread some right away on my gardenia. I knew about the roses but not the gardenia. Great info!

  19. gardeningAngel

     /  November 12, 2009

    I use Epson Salts with my roses (they need all the help they can get here), and also for the nice long soaking baths. Thanks for the information about the gardenias, alas we can't grow them here except in containers to take in during the winter. I love their smell and the purity of the white petals. Your pictures are very pretty.

  20. Janet

     /  November 12, 2009

    Wonderful posting! Great information. I will refer back to it for my gardenias.

  21. T Opdycke

     /  November 12, 2009

    Today is a day of learning. I've never heard of using Epsom salt in the garden. Thanks for tickling my brain, Nell Jean, I'll do a bit more research.

  22. Hocking Hills Gardener

     /  November 12, 2009

    Great post! I have read about the use of Epson salt for plants but have never tried it. I may have to try it next Spring to see if it helps my roses.Thank you for the information Nell Jean.

  23. Tom - 7th Street Cottage

     /  November 12, 2009

    I've been giving people advice on using Epson salt with gardenias all year.
    It's also good to use on Brugmansia (Angel's Trumpet).
    Great post.

  24. Deborah at Kilbourne Grove

     /  November 12, 2009

    I have often read about epsom salts with roses, but have never tried it.

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