How much to water: the tuna can test
Your sprinkler timer says 20 minutes. Your lawn has no idea what that means. A few empty cans tell you how much water it actually got.
Most lawns need about an inch of water a week in the growing season, rain included. The only way to know what your sprinklers put down is to measure it.
The test
- Set 4–6 empty tuna or cat-food cans around one sprinkler zone.
- Run that zone for exactly 15 minutes.
- Measure the water depth in each can with a ruler and average them.
- Use the calculator below to get minutes per week.
How to split it
Water deeply one or two times a week instead of a little every day. Deep, infrequent watering pushes roots down. Always water early in the morning.
Watering calculator
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