No, in fact Epsom salt may hasten the spread of blight. It can overload the soil with magnesium, which prevents the plant from getting enough calcium.
Treating Blight
If blight has already spread to more than just a few plant leaves, apply Daconil® Fungicide Ready-To-Use, which kills fungal spores and keeps blight from causing further damage.
Mix fat-free milk with water in a 1:1 ratio and apply it using a spray bottle. Spray the solution directly onto the clean leaves of your tomatoes. Milk-and-water solution coats the leaves and leads to the growth of an invisible fungus that frightens off black spot!
Epsom salt is inexpensive and readily available. It is recommended for tomatoes, peppers and roses, but I use it around citrus trees, in the veggie beds, and anywhere leaves are looking sickly. The Epsom salt bag recommends sprinkling 2 tablespoons around the base of each plant, so you can see a little goes a long way.
Baking soda spray is reputed to be effective to treat late blight, early blight and other fungus problems. Mix 1 tbsp. baking soda and 2 1/2 tbsp. vegetable oil in one gallon of water. After mixing, add one half tsp. of dish soap. Spray the tomato plant once a week, coating the leaves and stems.
If you get an fungal outbreak like 'Leaf Spot' or 'Early Blight' use hydrogen peroxide to get the diseases under control. My goal with diseases is to manage them down as to still get get great production from my tomato plants.
If you have had blighted tomatoes in the past, rotate crops on a three-year cycle to help keep soil disease-free. This means rotating where you plant your tomatoes and allowing three years to pass before planting them in the same spot. The absence of live plants should rid the soil of the disease in this time.
Adding Epsom salts to soil that already has sufficient magnesium can actually harm your soil and plants, such as by inhibiting calcium uptake. Spraying Epsom salt solutions on plant leaves can cause leaf scorch. Excess magnesium can increase mineral contamination in water that percolates through soil.
There are two ways to use Epsom salts for tomatoes.
1. Mix 1 tbsp of Epsom salts into the soil at the bottom of the planting hole when transplanting tomatoes or peppers or mix 1 tbsp in a gallon of water and water the transplant. It may help plants absorb Calcium and other nutrients from the soil.
Beans and leafy vegetables. Coniferous trees. Tropical palms don't like Epsom salt, either. Insect-eating plants such as Pitcher plants, sundews and Venus flytraps are other plants that do not like Epsom salt.
Once a tomato plant has a blight, it's almost impossible to completely get rid of it. However, if you are very attentive with treatment measures, your tomato plant may still produce some fruit for you. Does epsom salt prevent tomato blight? No, in fact Epsom salt may hasten the spread of blight.
Some of the more effective products include; cyazofamid (i.e. Ranman), propamocarb (Previcur Flex), fluopicolide (i.e. Presidio), mandipropamid + difenoconazole (i.e. Revus Top), cymoxanil (i.e. Curzate), and cymoxanil + famoxadone (Tanos).
To create a solution that prevents and treats disease, add a heaping tablespoon of baking soda, a teaspoon of vegetable oil, and a small amount of mild soap to a gallon of water and spray the tomato plants with this solution. This needs to be reapplied regularly to maintain its efficiency.
Mature fruit will rot more quickly if infected. Can tomato plants recover from blight? You may still get edible fruit from a plant that has blight, just make sure any fruit you eat has no signs of the disease. However, an infected plant will not fully recover.
The baking soda absorbs into the soil and lowers its acidity levels giving you tomatoes that are more sweet than tart. Although I haven't done this with every plant on my patio, having a few extra sweet nuggets to mix into a fresh tomato salad has been a wonderful discovery!
Tomatoes are prone to magnesium deficiency later in the growing season, which can show with yellowing leaves and diminished production. Ultra Epsom Salt treatments at the beginning of their planting and throughout their seasonal life can help to prevent and remedy magnesium deficiency in your tomato plants.
The product is high in magnesium sulfate, which increases phosphorus availability to plants, boosting their growth, vigor and blooms. So, yes, one teaspoon for each foot of the plant's height sprinkled around its base (and watered well) can help achieve bigger and better roses if applied once a year in spring.
Tomatoes thrive in loamy soils with good drainage and high organic matter content. Adding composted coffee grounds to planting beds is a great way to build healthy soil for tomato planting but won't provide all the required nutrients.
Epsom salt
Sprinkle Epsom salts onto your trash can lid or around the areas that pests like to burrow into or dig around. Epsom salts will deter most any pests, including raccoons, mice, and squirrels among others.”
Depending on the size of your garden, compile enough of each component to contribute a moderate amount to each hungry plant. Combine the two together, crush the eggshells by hand even more (which should be easier now that they're fully dry), and sprinkle the mixture across the soil bed.
Epsom salt can deliver great results in gardens that have a magnesium deficiency when used correctly. Roses, tomatoes, peppers, pansies, petunias, and impatiens particularly love Epsom salt, and all need high levels of magnesium for optimal growth.
Utilizing a fungicide is one key way you can address your blight problem. After removing any infected leaves, you can spray the surrounding area with a copper fungicide or biofungicide to help contain the problem if it hasn't spread too far.
If you see any signs of this blight you should remove infected leaves. If it spreads to more than 1/3 of a plant, it should be pulled and destroyed. Do not compost any parts of a tomato plant. When you do plant tomatoes, add a cup of lime to the bottom of each planting hole to prevent blossom end rot.
Try beans. Legumes and then the cruciferous crops, including brassicas, are what to plant after tomatoes. Legumes are known to trap nitrogen in nodules that form on their roots, adding nitrogen to the soil.