Why do we fertilize our plants? For growth and sustained health and production! Nutrients most frequently lacking for growth are nitrogen (N), phosphorus (P), and potassium (K).
• N (Nitrogen). This nutrient element provides dark green color in plants. It promotes rapid vegetative growth. Plants deficient in nitrogen have thin, spindly stems, pale or yellow foliage, and smaller than normal leaves.
• P (Phosphorus). This nutrient promotes early root formation, gives plants a rapid, vigorous start, and hastens blooming and maturity. Plants deficient in this element have thin, shortened stems, and the leaves often develop a purplish color.
• K (Potassium). Potassium or potash hastens ripening of fruit. Plant disease resistance as well as general plant health depend on this element. It is also important in developing plump, full seeds. Plants deficient in this element have graying or browning on the outer edges of older leaves.
The content of N, P, and K is specified on fertilizer bags. The analysis or grade refers to the percent by weight of nitrogen, phosphate, and potassium in that order. Thus, a 10-10-10 fertilizer contains 10 percent nitrogen (N), 10 percent phosphate (P2O5) and 10 percent potassium (K2O).
The winter before you begin to garden, you will want to get a sample of your garden soil tested to determine pH and nutrient content. The soil test provides a starting place for a soil improvement program. Unless you know the deficiencies in your garden soil, you are only guessing when you apply fertilizer. The soil test will tell you how much fertilizer you must add to your garden initially. It is then much easier to maintain a high level of fertility as you garden year after year.
