MILLS ORGANICS - ORGA CAL - 20LMills Orga Call is obtained from organic material (limestone) and plays a crucial role in keeping plants healthy at the cellular level. Orga Cal activates the enzymes needed for your plants to grow and is essential for reinforcing and maintaining the cell wall structure. The use of Orga Cal throughout the growing cycle results in stronger plants with larger and fuller flowers. Stimulating effect on the metabolism, which makes the plant grow faster.