Lawn Watering Guidelines
How much water does a lawn need per week?
Most lawns need 1 to 1.5 inches of water per week from rain and irrigation combined. Warm-season grasses like Bermuda and Zoysia need slightly less than cool-season types like Kentucky Bluegrass and fescue. Sandy soils drain quickly and need more frequent watering, while clay soils hold moisture longer and can go longer between sessions.
How long should I run my sprinklers?
A typical pop-up sprinkler covers about 100 sq ft at 1.5 GPM. To apply 1 inch of water on 1,000 sq ft you need about 623 gallons, which takes roughly 30–45 minutes depending on your system's flow rate. Use this calculator to get the exact run time for your sprinkler's GPM rating and your lawn size.
How many gallons does it take to water 1,000 square feet?
1 inch of water on 1,000 sq ft requires about 623 gallons. If you water 3 times per week, that's about 208 gallons per session. Knowing your sprinkler's GPM rate lets you convert gallons to run time: 208 gallons ÷ 2.0 GPM = 104 minutes per session.
Frequently Asked Questions
How much water does a lawn need per week?
Most lawns need 1 to 1.5 inches of water per week total (rain + irrigation). Cool-season grasses (fescue, bluegrass) need closer to 1.25 inches; warm-season grasses (Bermuda, Zoysia) need around 1 inch. Sandy soils need more frequent watering; clay soils retain water longer.
How do I calculate how long to run my sprinklers?
Divide the gallons needed by your sprinkler system's flow rate in GPM. For 1 inch on 1,000 sq ft: 623 gallons ÷ 2.0 GPM = 311 minutes, but split across 3 sessions that's about 104 minutes per session. Use the calculator above for your exact setup.
When is the best time to water your lawn?
Early morning (5–9 AM) is ideal — low wind, cooler temperatures reduce evaporation, and grass dries before evening which helps prevent fungal disease. Avoid watering at midday (high evaporation) or at night (wet grass overnight promotes disease).