Soil fixes
Heavy clay soil: add coarse sand — not beach sand — and compost. Sandy soil: add humus, or aged manure, or sawdust with some extra nitrogen. Heavy clay-rich soil also can be added.
To improve soil, add ground bark, made from various tree barks. Decomposed leaves and other compost are excellent conditioners, adding nutrients and structure to soil. Lime raises the pH of acidic soil and helps loosen clay soil. Decayed manure is best if composted. It is a good conditioner. Sand will improve drainage in clay soil. Topsoil often is used with another amendment to replace existing soil.
Fertilizers are labeled to show the percentage by weight of nitrogen (N), phosphorus (P), and potassium (K). Nitrogen is needed for leaf growth, phosphorus for root growth and fruit production. Potassium helps plants fight off diseases. Example: one 100-pound bag of 10-5-10 contains 10 pounds of nitrogen, 5 pounds of phosphorus, and 10 pounds of potassium. The rest is filler.