What does Epsom salt do for tomatoes?
Written by
Kiana Okafor
Reviewed by
Prof. Martin Thorne, Ph.D.Epsom salt will provide magnesium to tomato plants, but it confuses gardeners. It addresses yellowing leaves caused by a lack of magnesium. It won't cure #blossom-end-rot despite rumors. I learned that the hard way after losing my crop to misinformation. Whenever you want to add anything to your soil, it's best to test it first before making amendments. A lack of magnesium will result in yellow veins on older leaves.
Proper Uses
- Corrects magnesium deficiency: Yellow leaves with green veins
- Apply as foliar spray: 1 tbsp/gallon water
- Use soil drench every 4 weeks during fruiting
- Combine with balanced fertilizer applications
- Apply early morning to avoid leaf burn
Limitations
- No calcium content: Cannot prevent blossom end rot
- Ineffective for fungal/bacterial diseases
- Avoid in high-magnesium soils
- Never substitute for proper soil testing
- Excess causes potassium imbalance
Check the soil before using Epsom salt. A home kit will give a quick reading of magnesium levels. A professional test will provide you with a calcium ratio. I test my garden soil every spring. Anything less than 25 ppm needs an adjustment. A balanced soil will contain 50 to 100 parts per million (ppm) of magnesium. Don't guess when it comes to nutrients.
Use Epsom salt only when truly necessary, on an as-needed basis. Dissolve 1 tablespoon per gallon of fresh water. When a deficiency is detected, spray the top and bottom of the leaves until they are dripping for best results. Thereafter, water the soil monthly with the same solution. I apply it at sunrise if possible, so it absorbs best. If there is no improvement after two applications, discontinue. If excess occurs, more detriment than benefit results.
Select options you can utilize to address calcium challenges. Gypsum delivers calcium with no pH effect. Crushed eggshells work over several months. I incorporate both into my calcium management plan. For blossom end rot, be consistent with watering. Mulch helps support soil moisture levels. Balanced nutrition prevents most challenges.
Read the full article: 10 Common Tomato Diseases and Prevention Tips
