Premium DTPA-chelated iron for superior availability in alkaline soils up to pH 7.5 — where EDTA fails. 100% water-soluble for soil drench, foliar spray, and hydroponic applications.
Diethylenetriaminepentaacetic acid forms a stable complex with iron that remains plant-available in moderately alkaline soils up to pH 7.5 — extending effectiveness well beyond standard EDTA chelates.
High-concentration formula delivers a meaningful dose of available iron per application, allowing lower use rates while achieving rapid chlorosis correction in deficient plants.
Dissolves completely with no residue or clogging — fully compatible with drip lines, sprayers, and hydroponic recirculating systems for precise, uniform delivery.
Iron is essential for chlorophyll synthesis. Foliar applications can show early greening within 7–10 days, with full leaf recovery typically seen within 2–3 weeks.
DTPA chelation protects iron from reacting with bicarbonates in alkaline irrigation water — a major cause of iron tie-up in Western growing regions with high-pH water sources.
Effective as a foliar spray for rapid uptake, soil drench for sustained root-zone availability, fertigation injection for commercial operations, or as the iron component in custom hydroponic nutrient solutions.
Registered with the California Department of Food and Agriculture as a specialty fertilizer, meeting state standards for label accuracy, nutrient content, and permitted ingredients.
Independently lab tested for heavy metal content to verify purity and safety for use on edible crops, ornamentals, and in hydroponic food production environments.
Mixes cleanly with calcium nitrate, MAP, MKP, and most NPK fertilizers. Always perform a jar test before mixing with copper, zinc, or manganese chelates in concentrate form.
Manufactured at our California facility with quality control standards maintained throughout production — from raw material sourcing to final packaging.
Chelated Iron DTPA 11% is produced by reacting high-purity iron salts with DTPA (Diethylenetriaminepentaacetic acid), a synthetic aminopolycarboxylic acid chelating agent. The resulting complex is a fine, water-soluble powder with stable chelate bonds that resist breakdown across a broad soil pH range.
High-purity iron salt reacted with DTPA to form the chelate complex. Provides the 11% iron content in a plant-available, protected form.
Diethylenetriaminepentaacetic acid — a pentadentate chelator that binds iron through five coordination sites, creating a stronger complex than EDTA (four sites) and maintaining stability at higher soil pH.
Iron is the fourth most abundant element in the earth's crust, yet iron deficiency is one of the most common micronutrient problems in agriculture. The reason: at soil pH above 6.5, free ionic iron rapidly converts to insoluble iron hydroxides that roots cannot absorb. Chelation wraps iron in an organic molecule that keeps it soluble and plant-available despite alkaline conditions.
Iron is essential for chlorophyll synthesis, electron transport in photosynthesis, and numerous enzyme systems including those involved in nitrogen metabolism. Deficiency causes interveinal chlorosis (yellowing between green veins) on young leaves first, since iron is not mobile within the plant.
EDTA (four coordination sites) begins releasing iron at pH 6.5, leaving it susceptible to precipitation in alkaline soils. DTPA (five coordination sites) maintains its iron complex through pH 7.5, making it the appropriate choice for soils and irrigation water in the neutral-to-moderately-alkaline range common across California, Arizona, and the Western US.
Alkaline irrigation water high in bicarbonate (HCO₃⁻) is a primary driver of induced iron chlorosis. Bicarbonates raise the rhizosphere pH around roots, locking up iron even in soils that test adequate. DTPA chelation resists this bicarbonate-driven precipitation, keeping iron accessible at the root surface.
Best value for acidic soils. Higher iron content (13%) and lower cost. Not effective above pH 6.5. See Chelated Iron EDTA 13%.
This product. The right choice for neutral to moderately alkaline soils and high-bicarbonate irrigation water. Covers the pH range where most Western US growers operate.
For very alkaline soils above pH 7.5. Higher cost, lower iron content (typically 6%), but unmatched stability in extreme conditions. Use when DTPA is insufficient.
Results vary with soil pH, temperature, irrigation frequency, and severity of deficiency. Severe or long-standing chlorosis may require multiple applications.
For severe deficiencies, increase application frequency rather than concentration. Always test foliar spray on a few leaves first before full application.
| Plant Type | Rate | Frequency |
|---|---|---|
| Houseplants (6" pot) | 1–2 tsp per pot | Every 4–6 weeks |
| Garden Vegetables | 1–2 tbsp/gallon | Every 3–4 weeks |
| Shrubs | 2–4 tbsp per plant | 2–3 times/year |
| Trees | ¼–1 cup per tree | 2 times/year |
| Field Crops | 2–4 lbs/acre | As needed |
| Purpose | Rate | Frequency |
|---|---|---|
| Prevention | 1 tsp/gallon | Monthly |
| Mild Chlorosis | 2 tsp/gallon | Every 2 weeks |
| Severe Deficiency | 1 tbsp/gallon | Weekly until corrected |
| Commercial (dilute) | 1–2 lbs/100 gal | Full coverage spray |
Stock Solution Method (Recommended): Direct powder measurement for small reservoirs can lead to overdosing. Use the concentrate approach for precise control.
| Crop Type | Target ppm Fe | Notes |
|---|---|---|
| Leafy Greens | 2–3 ppm | Lower end of range |
| Tomatoes / Peppers | 2–4 ppm | Increase at fruiting stage |
| Strawberries | 3–4 ppm | Critical for flavor development |
| Herbs | 2–3 ppm | Standard range |
| Crop | Sensitivity | Special Notes |
|---|---|---|
| Citrus | Very High | Apply before spring flush |
| Roses | High | Monthly during growing season |
| Pin Oak | Very High | Inject or deep-root feed |
| Berries | High | Critical at fruit set |
| Tomatoes | Moderate | Apply at first flower |
For chlorotic citrus, roses, or pin oaks, apply a foliar spray (1 tbsp/gallon) for rapid greening while simultaneously drenching the root zone (2–4 tbsp/gallon). The foliar application provides immediate iron to the canopy while the soil drench builds availability over the following 4–6 weeks — reducing the need for repeat foliar treatments.
Refer to the Safety Data Sheet (SDS) for complete safety and emergency response information.
Iron deficiency rarely occurs in isolation. Correct the full picture by pairing Chelated Iron DTPA with complementary micronutrients and nutrients your plants need.
Manganese deficiency mimics iron chlorosis with similar interveinal yellowing. Often occurs alongside iron deficiency in alkaline soils — address both together.
Zinc deficiency is common in high-pH, sandy, or over-irrigated soils. Pair with iron DTPA for a complete chelated micronutrient program.
For growers with varied soil pH — keep EDTA on hand for acidic beds and DTPA for alkaline zones. Switch based on your soil test results.
Compatible tank mix partner — provides soluble calcium and nitrogen while chelated iron DTPA supplies micronutrient support in the same fertigation pass.
Iron DTPA uses Diethylenetriaminepentaacetic acid chelation, which binds iron through five coordination sites compared to EDTA's four. This stronger binding maintains iron solubility up to pH 7.5 versus EDTA's limit of pH 6.5. In practice, this means iron DTPA continues delivering available iron in the neutral-to-moderately-alkaline soil conditions common throughout California and the Western US, where EDTA-chelated products become ineffective. If your soil pH is consistently above 6.5, DTPA is the appropriate choice.
The primary signal is interveinal chlorosis — leaves that turn yellow between the veins while the veins themselves stay green — appearing on young leaves first. Iron deficiency is most common in plants growing in alkaline soils (pH above 6.5) or irrigated with high-bicarbonate water. If a soil test confirms adequate total iron but plants still show chlorosis, the iron is present but unavailable due to pH — that's exactly when chelated iron DTPA is needed. If soil pH is below 6.5, Chelated Iron EDTA 13% is a more economical option.
Foliar applications typically show early greening in 7–10 days, with more complete recovery in new growth within 2–3 weeks. Note that older, severely chlorotic leaves often will not regreen — recovery is most visible in new foliage emerging after treatment. Soil drench applications take longer to show results (2–3 weeks) but provide sustained availability for 4–6 weeks. For fastest correction of severe chlorosis, combine a foliar spray for immediate uptake with a soil drench for ongoing availability.
Use the stock solution method to avoid the precision challenges of weighing very small powder amounts. Dissolve 2 oz (57g) in 1 gallon of water to create a ~1,650 ppm Fe concentrate, then dose 1–2 teaspoons of this stock per 10 gallons of reservoir water to target 2–3 ppm Fe in the final solution. Always keep your iron stock tank separate from concentrated calcium or phosphate solutions — mixing these in concentrate form can cause precipitation. Test your reservoir with a ppm meter weekly and replenish as needed.
Yes, with some precautions. Chelated iron DTPA mixes cleanly with calcium nitrate, MAP, MKP, potassium sulfate, and most NPK fertilizers. Always add iron chelate to water first, then add other fertilizers — never add to a concentrated solution. Avoid mixing with high-phosphate concentrates, as iron can form iron phosphate precipitate in concentrated form. If mixing with other micronutrient chelates (copper, zinc, manganese), perform a jar test first: mix small amounts in the same proportions as your intended application and observe for 30 minutes before proceeding.
Plants with the highest iron demand and sensitivity to soil pH include citrus (particularly in Arizona and California), roses, pin oaks, azaleas, rhododendrons, gardenias, petunias, and most berry crops. Hydrangeas, blueberries, and stone fruits are also frequently affected. Any plant grown with alkaline irrigation water is at ongoing risk, since bicarbonates continuously raise rhizosphere pH and reduce iron availability even in soils that test adequate. Preventive DTPA applications before spring growth flush are especially effective for citrus and ornamental trees.
Every batch of Chelated Iron DTPA is independently tested for heavy metal content and verified against label specifications for iron percentage and chelation integrity. Our CDFA registration requires ongoing compliance with California's fertilizer material standards — ensuring you receive a consistent, accurately labeled product.
We stand behind every product we make. If you're not satisfied with your Chelated Iron DTPA for any reason within 90 days of purchase, contact us for a full refund — no questions asked. See our returns policy for details.
Greenway Biotech, Inc. has been producing and distributing specialty fertilizers from California for over 35 years. We manufacture our chelated micronutrients in-house at our Madera, CA facility — giving us direct control over quality at every step from raw materials to final packaging.
Check out our full FAQ page or contact our experts for personalized advice.
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