Wicked Organics Epsom Salts

Epsom salts, known chemically as magnesium sulfate (MgSO₄), is a versatile, naturally occurring mineral compound widely used as a soil amendment in organic gardening. Composed of magnesium, sulfur, and oxygen, it appears as small, colorless, water-soluble crystals. With its OMRI (Organic Materials Review Institute) listing, Epsom salts are approved for use in USDA Organic-certified farming and gardening, making them a go-to choice for eco-conscious gardeners. This guide answers common questions about Epsom salts, covering their composition, uses, application methods, and more.

Composition of Epsom Salts

Epsom salts are an inorganic compound with the chemical formula MgSO₄. They provide two essential secondary macronutrients:

• Magnesium: A core component of chlorophyll, critical for photosynthesis.

• Sulfur: Supports protein synthesis and enzyme function.

The OMRI designation ensures the product is free from synthetic additives, meeting strict organic standards. While naturally sourced from mineral deposits like kieserite or springs, commercial Epsom salts are processed for purity and consistency.

Is It Organic and OMRI-Listed?

Yes, Epsom Salts/Mag.Sul. OMRI is OMRI-listed, meaning it has been evaluated and approved by the Organic Materials Review Institute for use in certified organic operations under USDA National Organic Program standards. This makes it suitable for organic gardening and farming, ensuring compliance with natural production guidelines.

NPK Ratio

Epsom salts do not have an NPK (Nitrogen-Phosphorus-Potassium) ratio, as they do not contain these primary nutrients. Instead, they supply magnesium and sulfur, which are secondary macronutrients. If your soil requires nitrogen, phosphorus, or potassium, you’ll need to complement Epsom salts with a balanced fertilizer.

Secondary Nutrients and Micronutrients

• Secondary Nutrients: Epsom salts provide magnesium and sulfur, both vital for plant growth. Magnesium supports chlorophyll production, while sulfur aids in amino acid and enzyme synthesis.

• Micronutrients: Epsom salts do not contain micronutrients like iron, manganese, zinc, copper, molybdenum, boron, or chlorine. For micronutrient deficiencies, consider targeted amendments.

Form and Processing

• Form: Available in crystalline or granular form, resembling table salt, which dissolves easily in water for application.

• Natural vs. Processed: Sourced from natural mineral deposits, Epsom salts are processed for purity and consistency but remain synthetic-free, as confirmed by their OMRI listing.

Uses in Gardening

Epsom salts serve as a versatile soil amendment and fertilizer, offering the following benefits:

1. Magnesium Supplement: Corrects magnesium deficiencies, reducing symptoms like yellowing leaves.

2. Sulfur Source: Enhances plant vigor and enzyme function.

3. Improved Nutrient Uptake: Boosts absorption of other nutrients like nitrogen and phosphorus.

4. Soil Amendment: Balances magnesium and sulfur levels in deficient soils.

5. Plant Health: Enhances resistance to diseases and environmental stress.

Best Plants for Epsom Salts

Epsom salts are ideal for plants with high magnesium and sulfur needs, including:

• Tomatoes: Prevents blossom-end rot and boosts fruit production.

• Peppers: Enhances fruit quality and plant health.

• Roses: Promotes lush foliage and abundant blooms.

• Houseplants: Maintains healthy, green leaves.

• Potatoes: Supports tuber development.

• Leafy Greens: Improves chlorophyll production for better leaf quality.

• Fruit Trees: Enhances fruit yield and quality in citrus, apples, and peaches.

Application Methods

Epsom salts can be applied to garden beds, containers, raised beds, and field crops. Always conduct a soil test to confirm magnesium or sulfur deficiencies to avoid nutrient imbalances.

1. Garden Beds

• Preparation: Mix 1 cup per 100 square feet into the top 6 inches of soil before planting.

• Application: Sprinkle evenly and incorporate with a rake or hoe.

2. Potted Plants

• Dilution: Dissolve 1 tablespoon in 1 gallon of water.

• Application: Water monthly to deliver nutrients to roots.

3. Lawns

• Broadcast Application: Apply 3 pounds per 1,250 square feet using a spreader.

• Watering: Water thoroughly to dissolve and penetrate soil.

4. Trees and Shrubs

• Direct Application: Sprinkle 2 tablespoons per 9 square feet of root zone.

• Watering: Water well to aid absorption.

5. Roses

• Soil Application: Add 1 tablespoon per foot of plant height around the base.

• Foliar Spray: Dissolve 1 tablespoon in a gallon of water and spray leaves during the growing season.

6. Tomatoes and Peppers

• Soil Drench: Mix 1 tablespoon per gallon of water and apply every two weeks.

Application Rates

• Garden Plants: 1 tablespoon per gallon of water, monthly.

• Houseplants: 1 teaspoon per gallon of water, every 4–6 weeks.

• Lawns: 3 pounds per 1,250 square feet, 3–4 times per year.

• Roses: 1/2 cup per plant in spring and fall.

• Tomatoes and Peppers: 1 tablespoon per foot of plant height, every 6 weeks.

Frequency

Apply based on plant needs and soil conditions, typically monthly during the growing season. Conduct soil tests to avoid over-application.

Mixing with Other Amendments

Epsom salts can be used alone or with other amendments, depending on soil needs:

• Soil Test: Identify deficiencies in nitrogen, phosphorus, potassium, or other nutrients.

• Compatibility: Combine with balanced fertilizers if needed, ensuring application rates prevent over-fertilization.

• Pre-Charging: Not required; apply directly to soil or as a foliar spray.

Suitability for Different Settings

• Containers: Ideal for magnesium-hungry plants like tomatoes and roses (1 tablespoon per gallon of water, every few weeks).

• Raised Beds: Mix 1 cup per 100 square feet at planting or apply periodically.

• Field Crops: Broadcast 10–20 pounds per acre, based on soil tests.

Plant Growth Benefits

1. Magnesium Supply: Enhances photosynthesis for vigorous growth.

2. Nutrient Uptake: Improves absorption of other nutrients.

3. Flowering and Fruiting: Boosts blooms and fruit quality.

4. Stress Reduction: Increases resilience to drought and heat.

5. Seed Germination: Supports healthier seedlings.

6. Organic Compliance: OMRI-listed for organic gardening.

Soil and Environmental Impacts

• Soil Structure: Does not directly improve structure; use organic matter like compost for this purpose.

• Water Retention: Does not enhance moisture retention; consider organic amendments.

• Nutrient Holding Capacity: Does not increase cation exchange capacity; use compost or biochar for this.

• Microbial Life: Indirectly supports microbes by improving plant health, but does not provide organic matter for direct microbial support.

• pH Buffering: Neutral and does not significantly alter soil pH; use lime or sulfur for pH adjustments.

• Runoff/Leaching: Highly soluble, so excessive application may lead to leaching in sandy soils or heavy rain.

Safety and Environmental Considerations

• Pets and Children: Safe when used as directed. Store out of reach, mix thoroughly into soil, and supervise treated areas to prevent ingestion or skin irritation.

• Environmental Risks:

  • Overuse: Can disrupt nutrient balance or cause soil compaction.

  • Runoff: May contribute to water quality issues in heavy rainfall.

  • Mitigation: Apply based on soil tests and recommended rates.

Storage and Shelf Life

• Storage: Keep in a cool, dry, sealed container away from sunlight and contaminants.

• Shelf Life: Indefinite if stored properly; check for clumping due to moisture.

• Speed of Action: Effects visible within days (foliar: 24–48 hours; soil: within a week).

Additional Information

• Odor: Odorless, ideal for odor-sensitive gardeners.

• Edible Plants: Safe for use on edible crops like tomatoes and peppers when applied correctly.

• Sourcing: Derived from mineral deposits (e.g., Germany, USA); check packaging for specifics.

• Packaging: Typically sold in bags for easy handling.

• Bulk Pricing: Contact suppliers for bulk purchase options.

• Price Calculations:

  • Price per Pound: Total price ÷ weight (e.g., $10 for 5 lbs = $2/lb).

  • Price per Square Foot: Total price ÷ coverage area (e.g., $10 for 100 sq ft = $0.10/sq ft).

Conclusion

Epsom Salts/Mag.Sul. OMRI is a powerful, organic-compliant soil amendment that delivers magnesium and sulfur to support plant health. Ideal for tomatoes, roses, and other magnesium-loving plants, it promotes photosynthesis, nutrient uptake, and stress resilience. By applying it judiciously based on soil tests, gardeners can enhance plant growth without environmental risks, making it a staple in organic gardening.