The logistic growth function of hydrogen and tritium in stable organic bonds is determined with barley and maize as representatives of C3- and C4-plants. The growth rate as well as the growth increment of tritium in stable organic bonds has proved to be larger than the photosynthetically induced weight increase and weight increment of hydrogen. The native structure determining hydrogen bonds and water molecules, esp. those located in proteins, DNA and carbohydrates are considered to be significant deposits of stable organically bound tritium in plant material.