Chlorosis on citrus
What's Happening
Interveinal chlorosis (yellowing between leaf veins while veins stay green) in citrus occurs primarily from iron or magnesium deficiency. High soil pH (>7.5) locks these micronutrients in insoluble forms, preventing root uptake. Container citrus is especially vulnerable because limited soil volume leads to rapid pH shifts from hard tap water and fertilizer salts.
How to Fix It
- 1
Test soil pH using test strips—target 6.0-6.5 range; if >7.0, apply elemental sulfur at 1 tbsp per gallon of soil
- 2
Apply foliar spray: Mix 1 tsp chelated iron + 1 tsp Epsom salts per gallon of water; spray leaves until dripping
- 3
For magnesium deficiency specifically: Apply 1 tbsp Epsom salts dissolved in 1 gallon water as soil drench monthly
- 4
Flush soil: Run 3-4 pot volumes of plain water through soil to dissolve and leach accumulated salts
- 5
Repot if pH consistently >7.5: Use acidic citrus/cactus mix with 30% perlite for drainage
How to Prevent It
Maintain soil pH 6.0-6.5 using acidic potting mix or periodic sulfur amendments. Use rainwater or distilled water to prevent mineral buildup. Apply micronutrient-rich citrus fertilizer monthly during growing season. Flush soil with plain water monthly to leach excess salts.