Is Epsom salt effective for magnesium deficiency?
Written by
Liu Xiaohui
Reviewed by
Prof. Martin Thorne, Ph.D.Epsom salt is a remedy for plants with magnesium deficiency, when applied correctly. It rapidly delivers magnesium sulfate directly to plants that are experiencing difficulty or have exhibited symptoms of magnesium deficiency. Be sure to verify that a plant is magnesium-deficient through a soil test before using Epsom salt, as applying it to plants that are not deficient is not beneficial and can also lead to nutrient imbalances that harm your plants and the remainder of the soil. I have successfully reduced the deficits of tomatoes with confirmed magnesium deficiencies using Epsom salt at the correct time.
Soil Drench Method
- Dissolve 1-2 tablespoons per gallon of water
- Apply to moist soil around plant root zone
- Water thoroughly before application to prevent root burn
- Repeat every 2 weeks until symptoms improve
Foliar Spray Technique
- Use 2% solution (20g per liter of water)
- Apply at dawn or dusk to prevent leaf scorch
- Cover both leaf surfaces completely
- Avoid spraying under hot or bright sunlight conditions
Precautions
- Never apply to dry soil causing salt buildup
- Test on few leaves before full application
- Discontinue use once deficiency corrects
- Avoid using on seedlings or sensitive plants
The timing of use is crucial for efficacy. For foliar sprays, I prefer to apply them early in the morning when plant stomata are open. For soil drenches, I like to use them shortly before expected rainfall or irrigation is scheduled. I get my best results when treating plants at the first sign of deficiencies. Most often, you will observe a response to the treatment in 48 hours or less.
Observe plants after treatment. Within three days, you should see leaves starting to green. New growth should emerge bright green and healthy. I like to look at plants daily after application. Once symptoms resolve, discontinue use to prevent excessive accumulation in the plant. Excessive magnesium intake can lead to potassium deficiency issues.
Consider alternatives for sensitive plants or those with chronic deficiencies. One option is dolomitic lime that supplies magnesium while correcting the soil pH, as is sometimes recommended. Organic alternatives, such as composted manure or other organic matter, will provide slow-release nutrition. For acid-loving plants, consider using chelated magnesium supplements. The care you take ensures you have healthy, balanced nutrition for plants.
Read the full article: 7 Critical Signs of Magnesium Deficiency Plants
