Citrus Chlorosis Iron Magnesium on indoor citrus
What's Happening
Iron deficiency manifests as interveinal chlorosis on new growth (yellow leaves with green veins) because iron is immobile in plants—new growth suffers first. Magnesium deficiency shows on older leaves as interveinal yellowing progressing inward. Both deficiencies commonly occur in container citrus due to high pH (above 6.5) that locks up these nutrients, overwatering that leaches minerals, and lack of micronutrient supplementation. The symptoms often appear similar but affect different-aged leaves.
How to Fix It
- 1
Identify deficiency: Iron = new leaves yellow; Magnesium = old leaves yellow
- 2
pH adjustment: Test soil pH; if above 6.5, add sulfur or use acidic fertilizer to lower
- 3
Chelated iron: Apply liquid iron chelate (EDDHA or DTPA form) to soil every 2-3 weeks until new growth greens
- 4
Epsom salt: For magnesium, dissolve 2 tablespoons per gallon water; apply as soil drench monthly
- 5
Foliar spray: Mix 1 tsp chelated iron + 1 tsp Epsom salt per gallon; spray leaves for rapid uptake
- 6
Mulch: Add compost or acidic mulch to maintain lower pH and provide slow-release micronutrients
How to Prevent It
Use citrus-specific potting mix with micronutrients; fertilize with complete citrus fertilizer containing chelated micronutrients; maintain soil pH 5.5-6.5; avoid overwatering that leaches nutrients.