How to Water Your Lawn Correctly (Without Wasting a Drop)
Most lawns are watered wrong. Here is the deep-and-infrequent method, the exact amount per week, and how to measure it with a tuna can.
More lawns die from bad watering than from bad soil, bad seed, or bad fertilizer combined. The fix is simple: water deeply and infrequently.
The rule: one inch per week
Cool-season and warm-season lawns both want about one inch of water per week, including rainfall. Give it in one or two sessions, not seven.
Daily shallow watering trains roots to stay near the surface. Deep, infrequent watering drives roots down, where they can survive heat and drought.
How to measure one inch
Place three empty tuna cans at different distances from your sprinkler. Run the system for 30 minutes. Measure the average depth in the cans. Scale the total runtime so the average hits one inch.
Most systems need 60 to 90 minutes in one session to deliver a full inch across clay soils. Sandy soils need two shorter sessions to avoid runoff.
Best time of day
Early morning, between 4 and 9 a.m. Evening watering keeps the turf wet overnight and invites fungal disease. Midday wastes water to evaporation.
Special cases
- New sod: daily light watering for the first two weeks while roots knit. Transition to deep weekly watering by week four.
- New seed: keep the top half inch of soil moist with short, frequent cycles until germination, then ease off.
- Dormant warm-season grass in winter: stop watering except in extreme drought.
Signs of over and under watering
- Footprints that stay visible: under-watered.
- Mushrooms or constantly soft soil: over-watered.
- Brown tips with green base: under-watered.
- Yellow from the crown outward: likely a disease problem, not a water problem.
Related reading
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