Calcium

• Calcium is a major building block of all fruiting vegetables, including peppers. Calcium deficiency in tomatoes and peppers results in a condition called blossom end rot. This disorder first appears as a light-colored sunken area on pepper fruit, until a fungus in that area turns the spot black. Add calcium to the soil by turning in calcium carbonate or gypsum well in advance of planting, so it has the chance to break down in the soil. Consistent watering also helps ensure that the calcium gets to your pepper plants.
  
  

Nitrogen

• Nitrogen sparks growth in vegetable plants, including peppers. Use a high-nitrogen starter solution when setting out pepper transplants, and apply nitrogen fertilizer one or two times later in the growing season, especially if you see foliage turning pale green or yellow. On the other hand, don't dump on too much nitrogen, warns the University of Minnesota Extension, as this can lead to excessive foliage growth and an absence of pepper development.
  
  

Phosphorus and Potassium

• Phosphorus and potassium, along with nitrogen, meet the basic nutritional needs of most garden vegetables. Most vegetable garden fertilizers are primarily composed of nitrogen, phosphorus and potassium, in varying proportions. While regular, moderate applications of all three of these nutrients aid pepper plant growth, a dose of high-phosphorus fertilizer when peppers are transplanted early in the season helps prevent transplant shock. Do not overuse high-phosphorus fertilizers throughout the growing season, however, as excess phosphorus can run off and pollute water bodies.
  
  

Micronutrients

• Micronutrients like boron, copper, iron, manganese, molybdenum and zinc are necessary for healthy vegetable plant growth, but only in trace amounts. Increasing use of chemical fertilizers that contain only nitrogen, phosphorus and potassium, accompanied by more intensive planting methods, means that even the trace amounts of micronutrients necessary in the soil may run out, leaving your pepper plants at a deficit. Turning well-rotted manure or compost into your vegetable garden beds adds a wide array of micronutrients to the soil, along with organic matter that helps conserve soil moisture and provides an nurturing environment for your pepper plant roots.