Should You Use Epsom Salt For Tomatoes Blossom End Rot [TRUE]?

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Here is the question: Does Epsom Salt STOP Tomato Blossom End Rot?

How much Epsom salt for tomatoes?

tomatoes on the vine with blossom rotPin

NO! Epsom Salts helps promote or encourage Blossom End Rot. Find Out WHY!

Epsom salt has been a favorite tool for a long time in the growers’ toolbox. It has been touted as a secret cure-all for many plant ills.

Both professionals, master gardeners, and home growers use it for:

In the case of tomatoes, adding Epsom salt does not stop blossom end rot but increases the potential for plants to experience the blossom end rot disease. Read on to learn WHY.

What Is Blossom End Rot?

Most tomato growers are familiar with and experienced “blossom rot disease.”

Losses can be severe if steps are not taken to control its spread.

The disease is usually first seen when the fruit is ⅓ to ½ its full size. The disease appears as small water-soaked spots on the blossom end of the fruit.

As the fruit develops the “spot” grows and becomes dark.

Spots can remain small or grow to cover ⅓ to ½ of the fruit surface. The lesions dry, turn black and become leathery.

The Tomato Blossom Rot Disease:

  • Does not spread from plant to plant
  • Does not spread from fruit to fruit
  • Cannot be controlled with Fungicide sprays
  • Cannot be controlled with Insecticide sprays

Blossom Rot disease is physiological and depends on several environmental conditions as fruit develops.

What Causes The Blossom Rot?

Now that you know What blossom rot is, how is the bloom rot caused?

The disease is physiological, and the severity of the disease depends on several environmental conditions as fruit develops.

  • Calcium
  • Uptake of Water

During the production of fruit tomatoes need calcium and water.

When plants grow rapidly and suddenly experience the lack of water or drought, the disease often shows up.

Related: Tips On Deep Watering Your Tomatoes

When roots do not have the water and calcium the fruit requires the fruit starts to rot.

When cultivating occurs too close to plants, valuable water, and mineral absorbing roots are often destroyed.

The loss of roots reduces the plants’ ability to move the needed water and minerals to the fruit.

Tomato plants growing in poor soils without strong root systems or plants under stress are also suspect.

They too cannot move the needed nutrients and water the fruit requires.

Soils with high soluble salts reduce the availability of calcium to the plant.

tomato showing signs of blossom rotPin

Why Does Epsom Salt Increase The Changes Of Tomato Blossom End Rot?

If your tomatoes suffer from blossom rot will adding Epsom Salts to the soil, as a drench or an Epsom salt spray for tomatoes help stop, prevent or even control Blossom end rot tomatoes?


Tomato blossom end rot Epsom salt will not prevent rot on tomatoes, zucchini, peppers 2 etc.

It will promote or encourage it.

Many of us when planting peppers or tomatoes put a tablespoon of Epsom salts in the bottom of the hole when planting tomato seedlings.

We like the results of watching a healthy tomato plant grow, but when the plants get to the fruiting stage, the salts can increase the conditions for blossom-end rot.

Epsom salt contains magnesium sulfate – NOT Calcium.

Blossom rot is a calcium deficiency, not a magnesium deficiency!

The last sentence in the section above is vital to understand.

The more magnesium in the soil the less calcium the plant can absorb.

Related: What’s The Deal On Tomato Flower Dropping?

What Steps Can You Take To Reduce Blossom Rot?

NOTE: We like growing tomatoes in raised beds with soil designed for raised beds to maintain better control over the soil quality.

Below are some steps to help reduce blossom end rot.

  • Do a soil test at the beginning of the season
  • Irrigate tomatoes regularly and avoid extremes: too much water (soggy) or too little water (drought conditions). The plant moves the calcium by the uptake of water.
  • No deep cultivating. Don’t damage the roots needed to absorb calcium.
  • Use mulch to maintain a more even soil moisture.
  • Don’t over fertilize with high nitrogen fertilizers.
  • Apply calcium sprays to dime-sized or smaller fruits not the leaves. In one gallon of water mix four tablespoons of calcium nitrate. Spray plants 2 – 3 times per week.

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