Lawn irrigation best practices
Thank you for your question. For established lawns we recommend 1-1.5 inches of water per week. This would include rainfall.
Publications that can be shared:
Livable Lawns - http://udextension.s3.amazonaws.com/factsheet/wp-content/uploads/2013/04/D32536_LivableLawns_REVSIED_FINAL.pdf
If a green summer lawn is important, follow these recommendations for proper watering. 1. Wait until the soil dries out to water. 2. Water approximately every 7-10 days. 3. Water deeply and slowly to avoid runoff (2-4 hours). 4. Wet the soil to a depth of 4-6 inches. 5. Set sprinklers to avoid water waste.
Dealing with Drought in the Landscape – http://udextension.s3.amazonaws.com/factsheet/wp-content/uploads/2012/06/DroughtBrochure.pdf
Suggestions for watering various components of your landscape are described below. • Lawns Newly planted seed — water daily, preferably around mid-day, to moisten surface. Newly planted sod — water daily to wet the underlying soil. Established lawn (to keep lawn green) — 1.5 inches every 10 to 12 days, from rain or irrigation. You may spot-irrigate only those areas that need water. Realize that 940 gallons are required to apply 1.5 inches to 1,000 square feet (32 by 32 feet) of lawn. During a 6-week drought, 197,000 to 233,000 gallons of water would be required on the average (0.8 acre) Delaware lawn. Such water usage may be considered socially irresponsible. Established lawn (allowed to go “summer dormant”) — no water required. The grass will turn purplish-green or perhaps brown, but will regrow with the return of rainWatering for water conservation - http://extension.udel.edu/factsheets/lawn-management-for-water-conservation/