To encourage a variety of different crops in succession, and to discourage pests, each square is used for a different kind of plant (crop rotation) within the growing season. The number of plants per square depends on an individual plant's size. For example, a single tomato plant takes a full square, as might herbs such as oregano, basil or mint, while lettuce plants would be planted four per square, and up to sixteen per square of plants such as radish or carrots.