Last summer my water bill doubled, and my lawn still looked half dead by August. I was running the sprinkler every afternoon, right in the heat of the day, and watching most of it evaporate before it ever reached the roots.

Turns out the time of day matters more than how long you water.

Early morning wins

The best time to water is between 4 and 9 in the morning. The air is cool, the wind is usually calm, and the water has time to soak down to the roots before the sun starts baking it off.

Watering at midday is the worst. A good chunk of the water evaporates right off the surface, which is just money disappearing. And watering at night, while it seems smart, leaves the grass wet all night, which invites fungus and disease.

Water deep, not often

The other mistake I made was shallow daily watering. A light sprinkle every day trains the grass to grow shallow roots near the surface, which means it dries out faster and needs even more water.

• Water less often but deeper. One or two good soakings a week beats a little every day.
• Let the lawn dry between waterings. If you step on the grass and it springs back, it does not need water yet.
• Use a tuna can test. Put an empty can on the lawn and water until there is about half an inch in it. That is your ideal amount per session.

I also switched my sprinkler to run on a timer in the early morning while I am still asleep. Setting it and forgetting it was the easiest part. My water bill came down and the grass actually stayed green into fall.