Iron Chlorosis

Iron chlorosis is a nutritional disorder in cannabis plants characterized by yellowing of new growth while leaf veins remain relatively green, indicating insufficient iron availability despite adequate soil iron content. This condition typically results from pH imbalances—particularly high soil pH (alkaline conditions)—that reduce iron bioavailability, or from iron-poor growing media. Iron chlorosis can also develop in hydroponic systems with improper nutrient formulation or pH management. The disorder is distinct from nitrogen deficiency, which yellows older leaves first. While the plant's photosynthetic capacity is compromised during active chlorosis, recovery is generally possible through pH correction or chelated iron supplementation. Understanding iron chlorosis helps breeders and cultivators diagnose nutrient problems and refine growing protocols for consistent phenotype expression

Breeders monitor iron chlorosis response as a phenotypic indicator of plant vigor and nutrient uptake efficiency under standard cultivation conditions. Lines showing resistance to chlorosis in challenging pH environments may reflect stronger nutrient regulation traits worth preserving.