Epsom salt contains about 10 percent magnesium and 13 percent sulfur. Also called Magnesium sulfate, it is a highly water-soluble crystalline fertilizer.

Magnesium is critical for seed germination and the production of chlorophyll, it supports the transport of calcium into the upper parts of the tomato and facilitates the absorption of nutrients.

1. Epsom Salt for Potted Tomatoes

Dissolve 1 tablespoon of Epsom salt in 1 gallon of water. Water with this solution until it starts to drain from the bottom. You can do this in every 3 to 4 weeks. You can also use Epsom salt spray for tomato plants.

Also Read: How to grow Tomato on Balcony

2. Epsom Salt for Tomatoes while Planting

While transplanting the seedling, put one tablespoon Epsom salt in the bottom of the planting hole and cover this with a layer of soil. Make sure before planting that roots are not directly touching Epsom salt.

This will prevent stem rot and blossom end rot.

Also Read: Growing Tomatoes in Hanging Basket

3. Epsom Salt for Tomatoes during Growing Season

For the tomatoes growing on the ground, after planting till harvest–spray two tablespoon Epsom salt mixed in one gallon of water every month during growing season. This will encourage plant’s growth, prevent blossom end rot and makes tomato skin thick and red.

Tips and Warnings

  • It is best to get your soil tested before using any fertilizer as an excess of any nutrition can cause nutritional imbalance.
  • Potted tomato plants are prone to nutritional deficiencies, such as magnesium and sulfur, since nutrients leach out from the soil during the time of watering.
  • As with any ingredient, the success of Epsom salt for tomatoes depends on its balanced use.

Pin it

  • What the heck
  • September 21, 2015 At 11:43 pm
  • even better is SLOW-RELEASE fertilizer because it is released to the plant over a long period of time instead of all once
  • Reply
  • Ditte
  • March 14, 2016 At 3:26 am
  • I have been reading that Baking soda is good to put around the base of tomato plants. Makes the fruit sweeter, discourages rabbits and possible other creatures. Please give pros and cons regarding the use of Baking Soda.
  • Reply
  • joyce
  • May 31, 2016 At 8:07 pm
  • Not sure if the monthly spray is on the tomato plant or on the ground…..Thanks
  • Reply
  • admin
  • June 1, 2016 At 5:18 am
  • Hi Joyce,
  • You will have to spray the solution on plants foliage.
  • Reply
  • Birgitta
  • July 23, 2016 At 7:03 am
  • When, and how much to spray the epsom salt solution on the foliage? I tend to water at night, to give the leaves / foliage time to dry, and avoid sun scorch, as they’re on a 3rd floor patio with full sun all day til about 6 pm.
  • Reply
  • Gerals
  • August 6, 2016 At 7:16 pm
  • @Birgitta 1 tablespoon epsom salt per gallon of water. Spray the leaves/foliage and and you can pour some into the soil. every two weeks is good during growing season. Potted tomato plants tend to need more Magnesium
  • than tomatoes planted in the Garden.
  • Reply
  • Barbara W
  • August 7, 2017 At 3:06 am
  • Is it best to water at night or in the morning?
  • Reply
  • J Baker
  • September 17, 2017 At 9:22 am
  • I like to water at night so everything is dry by morning to prevent plant from burning up. If it’s going to not be a hot day, then I will water in the morning, being careful to moisten the soil only.
  • Reply
  • Javier
  • April 12, 2018 At 1:56 am
  • I’m new to growing tomatoes,I need all kinds of advices from the the people who knows how to do this.
  • Reply
  • Deiette
  • May 14, 2020 At 8:08 am
  • I have worked in a nursery for five years now and have learned it is best to water early in the morning so the plant has time to absorb the water before the heat kicks in for the day, also don’t make a habit of watering at night because that will overtime create a fungus throughout your garden
  • Reply
  • Erik
  • May 28, 2020 At 11:12 pm
  • Good advice. We’ve had mildew problems from watering at night, I think.
  • Reply
  • Deb Taylor
  • August 18, 2020 At 7:12 am
  • Can I just add 1 or 2 tbsp epsom salts to each tomato plant, worked into soil and watered afterwards?
  • Please Respond. I notice some sites do not allow the courtesy of responding. Thank you.
  • Reply
  • admin
  • September 9, 2020 At 10:46 pm
  • Hi Deb, thanks for dropping your comment. Yes, you can work 1 tablespoon of Epsom salt per foot of the plant’s height. Make sure to sprinkle it evenly around the plant.
  • Reply
  • Nicole
  • January 24, 2021 At 2:24 am
  • I have read your comments and it’s very engaging. I would like to know if you can add baking soda to cassava plant.
  • What can you use to remove blight from cassava leaves.
  • Reply
  • Nicole
  • January 24, 2021 At 2:28 am
  • What to use when tomato plant start to turn yellow
  • Reply
  • Belinda
  • September 4, 2021 At 3:46 pm
  • Would raised beds be considered a “ container” or in the ground?
  • Reply

even better is SLOW-RELEASE fertilizer because it is released to the plant over a long period of time instead of all once

I have been reading that Baking soda is good to put around the base of tomato plants. Makes the fruit sweeter, discourages rabbits and possible other creatures. Please give pros and cons regarding the use of Baking Soda.

  • admin
  • June 1, 2016 At 5:18 am
  • Hi Joyce,
  • You will have to spray the solution on plants foliage.
  • Reply

Not sure if the monthly spray is on the tomato plant or on the ground…..Thanks

Hi Joyce, You will have to spray the solution on plants foliage.

When, and how much to spray the epsom salt solution on the foliage? I tend to water at night, to give the leaves / foliage time to dry, and avoid sun scorch, as they’re on a 3rd floor patio with full sun all day til about 6 pm.

@Birgitta 1 tablespoon epsom salt per gallon of water. Spray the leaves/foliage and and you can pour some into the soil. every two weeks is good during growing season. Potted tomato plants tend to need more Magnesium than tomatoes planted in the Garden.

  • J Baker
  • September 17, 2017 At 9:22 am
  • I like to water at night so everything is dry by morning to prevent plant from burning up. If it’s going to not be a hot day, then I will water in the morning, being careful to moisten the soil only.
  • Reply

Is it best to water at night or in the morning?

I like to water at night so everything is dry by morning to prevent plant from burning up. If it’s going to not be a hot day, then I will water in the morning, being careful to moisten the soil only.

I’m new to growing tomatoes,I need all kinds of advices from the the people who knows how to do this.

  • Erik
  • May 28, 2020 At 11:12 pm
  • Good advice. We’ve had mildew problems from watering at night, I think.
  • Reply

I have worked in a nursery for five years now and have learned it is best to water early in the morning so the plant has time to absorb the water before the heat kicks in for the day, also don’t make a habit of watering at night because that will overtime create a fungus throughout your garden

Good advice. We’ve had mildew problems from watering at night, I think.

  • admin
  • September 9, 2020 At 10:46 pm
  • Hi Deb, thanks for dropping your comment. Yes, you can work 1 tablespoon of Epsom salt per foot of the plant’s height. Make sure to sprinkle it evenly around the plant.
  • Reply

Can I just add 1 or 2 tbsp epsom salts to each tomato plant, worked into soil and watered afterwards?

Please Respond. I notice some sites do not allow the courtesy of responding. Thank you.

Hi Deb, thanks for dropping your comment. Yes, you can work 1 tablespoon of Epsom salt per foot of the plant’s height. Make sure to sprinkle it evenly around the plant.

I have read your comments and it’s very engaging. I would like to know if you can add baking soda to cassava plant. What can you use to remove blight from cassava leaves.

What to use when tomato plant start to turn yellow

Would raised beds be considered a “ container” or in the ground?

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