How Much Should You Water?
Every lawn or garden is different, but the guidelines below offer some advice based on your weather, soil, and greenery. A sprinkler should only supplement the natural rainfall, though any lawn is ready for watering if the soil is dry 6 inches down.
One important rule, according to This Old House landscape contractor Roger Cook: Try to water only in the early morning. The midday heat will evaporate all your efforts, and plants watered later don't dry before nightfall, leaving them vulnerable to fungal diseases.