What is the best time of day to water your lawn? This is a very common question that just about everybody with a lawn wants to know. I have heard of and seen many practices regarding this topic, and I have come to the conclusion that many people have it wrong. Even people who have done research and combine the research with their common sense often get it wrong.
Your lawn needs about one inch of water per week. Too much water or too little water is not healthy for your lawn. The best way to accomplish this is with one really thorough soaking at the right time. Watering every day a little bit, or walking around your lawn spraying your hose every day may actually spray your lawn with the required inch per week, but your lawn still most probably will not be getting the required inch per week. This explains why daily watering is pointless. Your lawn does not require that much water anyway. Watering your lawn a thorough inch every day will only be detrimental to your lawn, and spraying it every day a little bit is completely pointless, since it will just evaporate when the sun comes up.
The best time of day to water your lawn is at about three or four in the morning when the water pressure is the highest. This way you will accomplish two vital things:
1. The water will have a chance to sufficiently soak into the topsoil.
2. Whatever water is left over will be evaporated when the sun comes up, thereby not giving the water a chance to create any fungi or molds which come about when water just sits around on the surface of your lawn.
If you have an automatic sprinkler system, it is very easy to set it at the right time for the right amount of water. However, if you have a job which allows you to sleep at night, waking up at three thirty in the morning to water your lawn may not be the best way to keep that job. I would certainly never even consider waking up that early in the morning to water my lawn.
The next best thing which will still accomplish these two vital effects is to water your lawn as early in the morning as possible BEFORE THE SUN COMES UP. This way most of the water will still soak into the topsoil, and whatever water is left over will be evaporated as soon as the sun comes out and starts heating things up. This early morning time can also be very challenging, since most of us either need to get ready for work, eat breakfast, drive carpool, or do one of the other million things we all need to do in the morning hours.
If watering your lawn in the early morning hours is not possible, the next best time of day to water your lawn is in the evening after the sun has already cooled down significantly. This will allow the water to soak into the topsoil properly. However, the leftover water will lay around all night long until the sun comes out and evaporates it. This can cause various fungi and molds to grow in your lawn, but it is still better than nothing.
The worst time of day to water your lawn is in the afternoon when the sun is beating down at full strength. The water will evaporate almost as quickly as it lands on your lawn, making this watering completely worthless. I see automatic sprinklers going on in the middle of the day all the time, but let me assure you that this accomplishes nothing unless the sprinklers stay on for hours at a time. Watering your lawn in the afternoon in such a way that will provide an ample amount of water to soak into the topsoil takes significantly more time and water than watering in the early morning, and is therefore almost always completely pointless. For this same reason, walking around with a hose and spraying your lawn is also basically pointless, since your lawn will not get anything close to the inch of water that it requires. The water will instead evaporate almost instantly.
The best way to figure out if you lawn is getting the required inch per week is to put out a few empty cans next to your garden or lawn and to see if it fills up an inch high of water. If you have a sprinkler system, this is a good way to see how long it takes for the sprinklers to soak your lawn with an inch of water. However long it takes to fill up the cans with an inch of water is a pretty good indicator of how long it takes to soak your lawn with an inch of water.