In order to secure the ideal condition for seed germination and plant growth, a seed-bed for planting should not be too deep and mellow. The soil should be mellow and well pulverized only about as deep as the seed is to be planted. Below this the soil should be firm and well settled, making a good connection with the subsoil, so that the water stored therein may be drawn up into the surface soil. The firm soil below the seed supplies the needed moisture, while the mellow soil above it allows sufficient circulation of air to supply oxygen and favors the warming of the soil by gathering the heat of sunshine during the day and acting as a blanket to conserve the soil heat during the night.