Iron-deficient leaves of a camellia plant (Camellia sp.). A lack of iron causes decreased production of the green pigment chlorophyll, making the leaf paler. Chlorophyll is the pigment responsible for photosynthesis. A lack of chlorophyll means that the plant cannot make enough food for itself, and it may die. Iron deficiency is usually due to either the soil being low in iron, or by the soil having too high a pH (high alkalinity), which makes the iron unavailable to the plant.