XTREME CalCarb Calcium Carbonate Foliar Spray It is foliage spray that energizes plants and promotes photosynthesis. It is a proprietary form of calcium carbonate whose weak molecular bonds enables it to be absorbed through the underside of plant leaves. CALCARB enters through the stoma on the underside of plant leaves where it is then broken down. CALCARB boosts new plant growth and promotes the process of photosynthesis. It may also prevent blossom end rot, powdery mildew, and treat calcium-deficiencies within the foliage of plants. Why is CALCARB and important addition to any garden? CALCARB increases photosynthesis, which is the natural process through which plants utilize solar energy and carbon in order to fuel new growth. CALCARB helps fuels this process and keep your plants happy and full of energy.