How Plants Use Calcium

• Calcium assists plant growth in several ways. Plants use it to build strong walls for the cells, and other necessary minerals travel in combination with calcium.
  
  

Variety of Sources

• Calcium is added to the soil in a variety of ways. Gypsum is often used because it provides the necessary calcium and sulfur without raising the soil pH. Dolomittic limestone is 46 percent calcium and 38 percent magnesium. Calcitic limestone is over 90 percent calcium. Both raise the soil pH level.
  
  

Lasts Several Years

• Large amounts of calcium should never be added with fertilizer. It is best to add the mineral five to six months before adding any fertilizer. An application is normally good for several years before it needs replacing.
  
  

Eggshells

• An easy way to provide calcium to the soil is to compost eggshells. Rinse them to remove any traces of raw egg. Crumble the shells to make decomposition easier and mix them into the compost. Some gardeners bake the shells, powder them in a blender, and sprinkle the dust directly on the garden soil. Doing this on an ongoing basis ensures the soil always has an adequate supply of calcium.