Seed placement is critical and should not be deeper than 0.5 to 1.5 cm, depending on soil moisture and texture. Seed will germinate better at the deeper part of a drier surface soil; the heavier the texture, the shallower should the seed be placed. Seedlings depend on carbohydrates stored in the seed for growth through the soil until the leaves emerge into sunlight and start photosynthesizing. If the seed is placed too deeply, the seedlings may exhaust their energy stores before emerging green tissue is able to transform sunlight into usable energy. Good quality seed, with germination in excess of 85% and free of weed seeds (98% pure or better), is a major prerequisite (see Chapter 23) for achieving excellent stands.