Calcium – An Important Plant Nutrient

Michelle RobertsPlanting Tips

Preparing beds

The time to start planting a garden is fast approaching.  In some areas of the country, it is already here.  One of the most important steps to success in the garden is proper soil preparation. The soil is key to healthy, vibrant plants and people. In studying how to plant a garden, focus a lot of attention on the soil and necessary plant nutrients.

“The nutrient delivery system for our food must begin with calcium in the soil. Calcium is an important mineral and absolutely necessary for proper function in plants and in people. It is vital to all biology.” ~ Jon Frank of International Ag Labs and High Brix Gardens

Most gardeners focus on the Big Three, “Nitrogen, Phosphorus, and Potassium”  when they add supplements, yet without proper amounts of calcium, plants can’t absorb the other three nutrients very easily.  Calcium happens to be one of the most deficient plant nutrients in soils.

Typically acidic soils are thought to be lower in calcium and alkaline soils high, however, calcium may become deficient in both acid and alkaline soils. Calcium deficiencies are developed through the normal cycles of growing crops, as many crops pull large amounts of calcium from the soil.  Another cause is leaching from rain and sprinkler water. Incorporation of organic matter also steps up losses in calcium.  Crop requirements for actual calcium oxide are equal to and often higher than the requirements for nitrogen, phosphorus, or potassium, yet seldom is enough calcium added in the home garden.

Limestone is the most common and the most inexpensive source of calcium. It can be quarried and crushed quite easily. Crushed mined stone can be added to your beds, but should not be left on top, it needs to be worked in and made available to the plant roots at about 6 to 8 inches deep. Crushed eggshells, Dolomite Lime, Azomite, and gypsum are also typical ways of adding calcium to the soil.

Some specific rolls of calcium

  • Aids in controlling disease in some crops
  • Aids in absorption of trace elements
  • Improves granular texture of soil allowing water, oxygen, and nutrients to flow
  • Stimulates the activity of favorable microorganisms, which release nitrogen in the soil
  • Determines the volume of yield
  • Strengthens the cell wall

It is always a good idea to have your soils analyzed for nutrient values.  Soil testing is usually available in each state through the extension services.  Calcium and lime are names commonly used for the same material.  It is usually applied separately because of its small size, but is compatible with other fertilizer compounds.  Typically gypsum is used to lime alkaline soils.