As a general rule, lawns need between one and two inches of water per week. The challenge is to make certain that all areas of the lawn are getting their required amount.
For new gardeners especially, a very common question is “how often should I water my lawn”? It seems like it would be an easy question to answer, but there are so many variables with home lawn conditions that there is not a simple answer. If your lawn looks good for most of the year and you are happy with the way it looks, then you must be doing what is right for you and your lawn. But if your lawn does not look quite like you think it should, and even though there are usually not exact answers for how much to water a lawn in the summer, there are some general guidelines to follow.
For starters, the kind of grass seed that was planted and the type of soil will contribute as to how much water will be needed during the summer months. For those with established lawns, these two questions would be better addressed in the fall which is an ideal time to re-seed a lawn and perhaps add new soil at the same time.
As a general rule, lawns need between one and two inches of water per week. The challenge is to make certain that all areas of the lawn are getting their required amount. If the lawn area has an established sprinkler system, be sure to carefully check each sprinkler head to be certain that it is not clogged. If sprinkler heads are along the border of the lawn with planting of flowers and shrubs behind it, check to make sure that leaves and branches are not obstructing the water flow. Plants grow fast and checking for obstructions should be done regularly.
If an oscillating sprinkler is used, figure out the optimum locations to set it so that it can get water to all areas within the pattern of the spray. Just as the heads of a sprinkler need to be checked for clogging, the holes on an oscillating sprinkler also need to be checked. It is very easy for one or two to become clogged.
For either a sprinkler system or an oscillating sprinkler, there is what I refer to as the ‘tuna can’ test. Place tuna cans, or something similar, at intervals throughout the lawn. Then turn the water on and set a timer for a specific length of time. After the specific time, check the cans, you will be able to tell if the entire area is getting water and also how much water. By experimenting, you can learn how long the water needs to be running to get the required moisture.
Early morning watering is the most efficient. There is less evaporation and thus less water waste. Watering in the evening can, in some cases, encourage certain lawn diseases. During the hottest days of summer, it may be beneficial to water twice a week rather than once. The lawn will tell you if it needs water as the grass blades will look wilted just as the leaves on a plant wilt when needing water. When mowing in the summer, let the grass grow a little taller as this will help shade the soil. Generally, when mowing, do not cut off more than one-third of the height of the grass.
If there are areas that seem to wilt quickly, this could indicate that a large rock might be just below the surface and is preventing the roots from growing into the soil. Where there is standing water, this would be an indication that the drainage needs to be improved. If you live in an area where there are water restrictions, the lawn is not going to look lush. It might be tempting to fertilize it, but do NOT fertilize under these conditions. Fertilizer will promote growth which will not be supported by adequate moisture. Wait until the fall rainy season arrives to fertilize.
Be observant of your lawn so you can be aware of areas that do not quite look right. Even without any major issues, having a soil test every few years is recommended. A lawn is going to need maintenance and care just like other plants. While the current trend is for homes to have smaller lawns, even a small lawn can highlight a garden and provide multiple uses for recreation.