Lawns should be watered on a regular basis during the growing season. The best time to irrigate your lawn is in the spring and fall, before or after rainfall. Watering can also be done as needed throughout the summer months. Most gardeners recommend a period of one inch per week for maintenance watering from April through October, but this amount varies depending upon temperature and rain amounts. In general, you will need to apply about two inches of water for each month that it rains at your site – which means about five inches if no rain falls there during that month. This figure applies to established turf grasses only – newly planted trees and shrubs may require more water than recommended here – so use caution when applying our recommendations for irrigation to new plantings!