Most lawns need about three or four applications of fertilizer per year. In general, warm-season grasses should be fed two to four weeks after the last freeze in the spring. The feedings should then be repeated in eight week intervals until the fall. Cool-season grasses should be fed in mid-fall, and again in early winter, in late winter, and in the spring. The timing of garden fertilizing depends on the type of plants, fruits, flowers, and vegetables planted. This is because the proportion proportion of nutrients needed varies according to grass or vegetation type, soil type, and the season. To determine the amount you need, figure the size of the area to be fertilized in square feet. The label on the fertilizer you choose will tell how much needs to be spread per square foot. Make sure to spread evenly and avoid overlapping fertilized areas. Water your lawn and garden early in the morning or at night, when there is little wind and less heat. Water thoroughly, but avoid causing puddles. To check if you are watering correctly, wait fifteen to twenty minutes after watering, then use a trowel to cut through the grass to a depth of at least six inches. The soil should be moist, but not wet, in order to provide enough water for the root zone. For more information on feeding and watering, consult a lawn care professional in your area.