|According to a recent soil test, my vegetable gardens are deficient in nitrogen and phosphorus and depleted in potash, and my perennial gardens are deficient in nitrogen and potash, but adequate in phosphorus. How do I replenish these nutrients?
|You could use a complete-analysis inorganic, granular fertilizer, such as a 5-5-5 or a 10-10-10, which would provide nitrogen, phosphorus and potassium. I like using longer-acting organic fertilizers such as a dried fish product that contains nitrogen and phosphorus; and greensand, which provides potassium. Alfalfa meal and cottonseed meal also supply all three nutrients but are highest in nitrogen. I wouldn't worry about adding more phosphorus to the perennial beds that already have an adequate supply. Phosphorus is released so slowly in the soil that it's hard to overdo it. Nitrogen, on the other hand, is more readily available to plants, so it's easier to overfertilize. Nitrogen also leaches quickly from the soil into the ground water below, so apply high nitrogen fertilizers right before planting.