How to Make Chelated Iron for Your Garden

Iron deficiency, known as chlorosis, affects up to 30% of plants in alkaline soils, turning leaves yellow while veins remain green. Learning how to make chelated iron can solve this problem by providing plants with an easily absorbable form of this crucial nutrient.

Quick Summary

Creating a chelated iron solution involves combining an iron source, like ferrous sulfate, with a chelating agent such as citric acid or EDTA. The agent binds the iron, preventing it from becoming unavailable in high-pH soil. This homemade fertilizer can be applied as a foliar spray or a soil drench for improved plant health.

Key Points

• Combine Iron Source and Chelator: Mix ferrous sulfate with a chelating agent like citric acid or glycine in water.

• DIY Citric Acid Method: A simple recipe involves dissolving ferrous sulfate and citric acid powder in water for an effective, low-cost solution.

• Amino Acid Chelation: An advanced technique uses heated, deaerated water with ferrous sulfate and glycine for a more stable chelate.

• Application Methods: Use the homemade chelate as a foliar spray for quick results or a soil drench for longer-term root absorption.

• Homemade vs. Commercial: DIY chelates are cheaper and customizable but less stable in high-pH soil than specific commercial formulas like EDDHA.

• Follow Safety Precautions: Always wear gloves and eye protection when handling ferrous sulfate and work in a well-ventilated area.

Understanding the Science of Chelated Iron

Chelation is a natural process where a metal ion, like iron ($Fe^{2+}$), is encased by a larger organic molecule, called a chelator. The word "chelate" comes from the Greek word for "claw" because the chelator molecule holds the iron ion in a pincer-like grip. This protects the iron from reacting with other soil compounds, especially in alkaline conditions, where it would otherwise become insoluble and unavailable to plant roots. While commercial products are available, making your own chelated iron is a cost-effective alternative for gardeners.

Simple DIY Chelated Iron Recipe with Citric Acid

This method uses citric acid, a weak organic acid, to chelate iron. It's a popular choice for home gardeners due to its accessibility and relative safety.

Ingredients and Materials:

• 1 tablespoon of ferrous sulfate (iron sulfate)
• 1 teaspoon of citric acid powder (or 1/2 cup of fresh lemon juice)
• 1 gallon of water (preferably distilled to avoid mineral interference)
• Non-reactive container (glass, plastic)
• Stirring utensil
• Spray bottle or watering can

Instructions:

1. Fill your container with about half a gallon of warm water. Using warm water helps with the dissolution process.
2. Carefully add the tablespoon of ferrous sulfate and stir until it is completely dissolved. Wear gloves and eye protection when handling the powder.
3. Add the teaspoon of citric acid powder to the solution and stir. If using lemon juice, add it now. You will see the solution's color change, indicating the chelation process is occurring.
4. Add the remaining water to reach the one-gallon mark and mix thoroughly.
5. Transfer the solution to a spray bottle for foliar application or use a watering can for a soil drench.

Method for Chelated Iron Using Amino Acids

For an alternative approach, a chelate can be created using amino acids and citric acid. This mimics some commercial organic chelate products and is highly effective.

Ingredients and Materials:

• 1 tablespoon ferrous sulfate
• 1 tablespoon glycine (a common amino acid)
• 1 teaspoon citric acid
• 1 gallon of distilled or deaerated water
• Non-reactive container
• Heating element (hot plate, stove)

Instructions:

1. Boil the water for 15-30 minutes and allow it to cool slightly to about 80°C (176°F). This removes dissolved air which can oxidize the iron prematurely.
2. In the warm water, dissolve the ferrous sulfate.
3. Separately, dissolve the glycine in a small amount of deaerated water and add it to the ferrous sulfate solution while stirring.
4. Mix in the citric acid powder and continue stirring at a constant warm temperature until the reaction is complete.
5. Allow the solution to cool before use.

Application Techniques for Your Homemade Chelates

How you apply your chelated iron is critical for its effectiveness. The chosen method depends on the severity of the deficiency and your soil type.

Foliar Spray: Best for a quick, temporary fix for plants with visible chlorosis. The plant's leaves can absorb the iron directly.

• Spray generously, covering the leaves completely, preferably in the evening or on a cool, cloudy day to prevent leaf burn.
• You can add a few drops of mild dish soap to help the solution stick to the leaves.

Soil Drench: Provides a more long-term solution by delivering chelated iron directly to the root zone.

• Dilute the prepared solution according to plant needs.
• Apply the solution to the soil around the base of the plant.
• Ensure the soil is already moist to prevent root shock.

Homemade vs. Commercial Chelated Iron

This comparison table outlines the benefits and drawbacks of making your own chelated iron versus buying a commercial product.

Feature	Homemade Chelated Iron	Commercial Chelated Iron
Cost	Much lower, as ingredients are inexpensive.	Higher, with premium formulas costing more.
Availability	Requires purchasing individual components.	Ready to use, widely available at garden centers.
Customization	Allows for adjusting strength and chelating agent.	Pre-formulated; different options for different soil pH levels (EDTA, DTPA, EDDHA).
Soil Suitability	Citric acid chelate is less stable in high pH soils (>7.0).	Formulas designed for specific pH ranges, offering better long-term stability in alkaline soils.
Shelf Life	Shorter shelf life; best used within a few weeks.	Longer, more stable shelf life with added preservatives.

Conclusion

Making your own chelated iron is an effective, affordable way to address iron deficiency in plants, particularly in slightly acidic to neutral soils. By combining ferrous sulfate with a chelating agent like citric acid, you can create a stable form of iron that your plants can readily absorb. While commercial products offer greater stability in high-alkaline soils, the DIY approach provides a practical, customizable, and budget-friendly solution for many home gardeners. By following a recipe for either a foliar spray or a soil drench, you can give your plants the iron boost they need for healthy, green foliage. Start with the simpler citric acid recipe and observe your plants' improved vitality. For more detailed insights on soil science, the Journal of AgriSearch offers comprehensive studies on chelation effects on plant growth, such as the one found at cabidigitallibrary.org.

Sources

Trees.com. "Chelated Iron for Plants - What You Need to Know." Trees.com, Feb 23, 2023. D JAWAHAR, S MURALI, D JEYA SUNDARA SHARMILA, and K SIVAKUMAR. "Synthesis and Characterization of Iron Chelates Using Organic and Amino acids as a Chelating Agents and Evaluation of Their Efficiency in Improving the Growth, Yield and Quality of Blackgram." Journal of AgriSearch, 8 (4): 325-330, 2021. ResearchGate. "Synthesis of iron chelates for remediation of iron deficiency in an alkaline and calcareous soil." ResearchGate, Aug 9, 2025. wikiHow. "3 Simple Ways to Give Plants Iron." wikihow.com, Feb 24, 2025. scienceinhydroponics.com. "How to prepare a low cost chelated micronutrient solution." scienceinhydroponics.com, May 17, 2020. Ubuy. "Chelated Iron 7-0-0 Liquid Iron for Lawns - Ubuy Pakistan." ubuy.com.pk.

Frequently Asked Questions

What are the common signs of iron deficiency in plants?

The most common sign is chlorosis, or yellowing of the leaves, especially on new growth, while the veins remain distinctly green.

Why can't plants absorb regular iron in some soils?

In alkaline or high-pH soils, regular iron in the soil reacts and becomes insoluble, meaning the plant's roots cannot absorb it effectively.

Is it better to apply chelated iron as a foliar spray or a soil drench?

A foliar spray provides a quick, temporary fix for visible symptoms, while a soil drench offers a more prolonged correction by allowing the roots to absorb the nutrient.

How do I make a simple chelated iron spray?

Dissolve 1 tablespoon of ferrous sulfate and 1 teaspoon of citric acid powder in one gallon of water for a basic, effective foliar spray.

What is the role of citric acid in making chelated iron?

Citric acid acts as a chelating agent, binding the iron ions and preventing them from precipitating out of the solution in high-pH soil environments.

Can I use household ingredients to make chelated iron?

Yes, common household items like ferrous sulfate (found in garden supplies) and citric acid or lemon juice can be used to create an effective chelated iron solution.

How long does homemade chelated iron last?

Homemade solutions, especially those without preservatives, have a shorter shelf life than commercial products. It's best to use them within a few weeks for maximum effectiveness.