Chelated Fertilizers
Correct micronutrient deficiencies fast — chelated iron, zinc, manganese & copper
Chelated fertilizers help keep iron, zinc, manganese, and copper soluble and available to plants — especially in neutral to alkaline soils where these micronutrients become tied up and difficult for roots to absorb. In high-pH conditions, chelated forms can significantly improve availability compared to non-chelated sulfate alternatives.
Greenway Biotech chelated micronutrients are water-soluble and suitable for soil drench, foliar spray, fertigation, and many hydroponic systems. Choose the chelate type based on your crop, deficiency symptom, and soil or solution pH.
Which chelated fertilizer do you need?
Match your deficiency symptom and soil pH to the right product. See individual product pages for full application rates. As a general reference, foliar rates are typically 1–2 tsp/gallon; soil drench rates vary by crop and deficiency severity.
| Product | Nutrient | Chelate | pH Range | Deficiency Symptom | Best Use Case |
|---|---|---|---|---|---|
| Chelated Iron EDTA | 13% Fe | EDTA | 4.0–7.0 | Interveinal chlorosis on young leaves (yellow between green veins) | Gardens, lawns, raised beds, and soil applications at pH 4–7 |
| Chelated Iron DTPA | 11% Fe | DTPA | 4.0–7.5 | Iron chlorosis in alkaline soils where EDTA underperforms | Western alkaline soils, hydroponic reservoirs, pH 6.5–7.5 |
| Chelated Zinc EDTA | 14% Zn | EDTA | 4.0–7.0 | Shortened internodes, small distorted leaves, interveinal chlorosis on new growth; in corn, white or striped young leaves | Corn, citrus, pecans, vegetables in neutral to alkaline soils |
| Chelated Manganese EDTA | 13% Mn | EDTA | 4.0–7.0 | Interveinal chlorosis on young leaves — veins stay green (mimics iron deficiency) | Soybeans, vegetables, citrus, and turf in high-pH soils |
| Chelated Copper EDTA | 14% Cu | EDTA | 4.0–7.5 | Wilting of new growth, pale or bluish-green leaves, shoot tip die-back | Organic soils, sandy soils, peats, palms, lemon trees |
EDTA vs. DTPA: which chelate should you choose?
Iron chelate stability by soil pH
If your soil pH is consistently below 6.5, Iron EDTA is typically the more cost-effective choice. If pH trends above 6.5 — common throughout the American West, limestone-rich regions, and wherever irrigation water is alkaline — Iron DTPA is often a better option, maintaining iron availability up to pH 7.5. For more strongly alkaline conditions (above pH 7.5), contact us about Iron EDDHA options.
For zinc, manganese, and copper deficiencies, EDTA chelation covers the vast majority of situations. In soils below pH 5.5, non-chelated sulfate forms may be more cost-effective. Note: in very acidic soils (below pH 5.0), manganese sulfate should be applied carefully — excess soluble manganese can reach phytotoxic levels in sensitive crops.
Read: Sulfate vs. Chelated Fertilizers — Key Differences Explained →
Diagnosing micronutrient deficiency
Where do symptoms appear first?
If yellowing starts on older, lower leaves, suspect nitrogen or magnesium — not a micronutrient. If it starts on the newest growth with green veins remaining, start with chelated iron and retest if symptoms persist.
Read: Iron's Role in Plant Growth — and How to Correct Deficiency →
Read: Essential Micronutrients for Plant Health — Full Guide →
Application methods & tank mixing
Tank mix compatibility
All products in this collection are designed to dissolve cleanly for use in drip irrigation, NFT, DWC, ebb-and-flow, and foliar sprayer systems. Mix order: water → chelate → NPK. Always dilute before combining concentrated chelates, and jar test any new combination before full-scale application.
Frequently asked questions
Why are my plant leaves turning yellow between the veins?
Interveinal chlorosis — yellow tissue between green veins on new leaves — is the classic sign of iron or manganese deficiency, and occurs most often in soils with pH above 6.5 where both nutrients become insoluble. A chelated iron fertilizer applied as a foliar spray typically shows improvement in new growth within 7–14 days. If symptoms persist, test for manganese — deficiencies of both often occur together in alkaline soils. Use Iron EDTA for pH 4–7; Iron DTPA for soils above pH 6.5.
How quickly will I see results after applying chelated iron or zinc?
Foliar application delivers the fastest response — most plants show visible improvement in new growth within 7–14 days. Soil drench takes longer (2–4 weeks) but provides more sustained correction. For severe deficiencies, combine both: foliar spray for immediate relief, soil drench for lasting correction. Existing chlorotic leaves rarely fully green up — monitor new growth as the indicator of recovery.
Are chelated fertilizers safe for hydroponics?
Yes — chelated micronutrients are the standard choice for hydroponic and soilless systems. Non-chelated sulfate forms can precipitate in recirculating nutrient solutions, clogging systems and rendering nutrients unavailable. Iron DTPA is preferred for recirculating hydroponics because it stays stable in solution up to pH 7.0. All products in this collection are designed to dissolve cleanly and are compatible with common hydroponic methods.
Can I mix chelated micronutrients in the same tank?
Many can be mixed in dilute solution, but always jar test first before full-scale application. Iron EDTA, Zinc EDTA, Manganese EDTA, and Copper EDTA are generally compatible with each other and most NPK fertilizers at working concentration. Use extra caution mixing copper or zinc chelates with iron chelates in concentrated stock solutions. Avoid combining any chelate with high-phosphate concentrates at stock concentration — phosphate can precipitate the chelated metals. Mix order: water first, then chelate, then NPK.
What's the difference between chelated and sulfate micronutrient fertilizers?
Sulfate fertilizers (Zinc Sulfate, Manganese Sulfate, Ferrous Sulfate) are lower cost and effective in acidic soils (pH below 6.0). Above pH 6.5, the metal ions in sulfate forms can convert to insoluble precipitates that roots cannot absorb. Chelated forms keep the metal soluble across a wider pH range, making them significantly more effective in alkaline conditions. See our full comparison: Sulfate vs. Chelated Fertilizers →
Are Greenway Biotech chelated fertilizers tested for heavy metals?
Yes. All products in this collection undergo third-party heavy metal testing. Results are available on our Heavy Metal Analysis page. We manufacture in-house at our Madera, California facility under CDFA registration, with quality control at every production stage.