It's turned HOT! No rain in sight! My lawn is looking thirsty! Summer is definitely upon us. It's time to turn on the sprinkler or irrigation system.
- How often should I water my lawn?
- When is the best time to water my lawn?
- How much water should I apply each time I water my lawn?
- Do I change my schedule when it gets really hot this summer?
- How do I know how much water I am applying each time I water?
- What other considerations are important?
There is no ONE right answer when it comes to watering a lawn. However, there are a couple of schools of thought that are popular among many turf experts and those of us at Central MO Turf Management subscribe to.
- Water the lawn once each day for three consecutive days - skip one day - water for two consecutive days - skip one day. TOTAL = 7 days. This system works great when your lawn is mowed the same day of each week as it allows you to schedule around your mowing day. Central MO Turf recommendation!
- Water the lawn every other day.
IMPORTANT: Don’t waste water. If it is raining or if the lawn is wet from a previous heavy rain and you have an irrigation system, pause the controller.
Water the lawn as early in the morning as possible after sunrise, we recommend between 4 a.m and 6 a.m. We do NOT recommend watering in the late evening or at night as this practice can result in a major fungus problem.
(Based on recent research, Central MO Turf Management recommends the following watering program and schedule)
- Set the "A" program on the controller for 10 – 15 minutes for each lawn rotor zone. Lawn spray zones should be set for 5 – 8 minutes. Landscape spray zones should be set for 3 – 5 minutes only.
- Set the "B" program on the controller for 10 – 15 minutes for each lawn rotor zone. Lawn spray zones should be set for 5 - 8 minutes only.
- Set the "C" program on the controller for 5 minutes for each lawn rotor zone. Lawn spray zones should be set for only 2 minutes.
- Set the "A" program to run early in the morning after sun rise. Example: 5:00 AM
- Set the "B" program to run following the end of the "A" program. Example: 6:00 AM
When you first start up the irrigation system in the spring, running the "A" program may be all that is required. As the temperatures warm into the 80's on a consistent basis it will be necessary to start up the "B" program also.
Splitting the watering schedule has two major benefits. First, it allows virtually all water to be soaked into the soil. Second, there is virtually no run off using this system and the homeowner gains maximum efficiency with no waste in the watering program.
If we have an extended hot and dry spell in the summer when temperatures rise into the upper 80's, the 90's or even 100's and the Heat Indices (combination of heat & humidity) reach the 90 or 100 degree level, adjustments to your watering schedule will become necessary. Moisture evaporation and heat stress will become very severe during that time.
Set the "C" Program on your Irrigation Controller for only 5 minutes per rotor zone around three o'clock each afternoon. If you have spray zones in the lawn, they should be set for only 2 minutes as they provide constant water to the lawn. Your objective here is to simply cool the grass and reduce the stress of the severe heat. NOTE: Be careful not to change your other programs. Each program should operate independently of each other.
IMPORTANT: If after following the prescribed watering schedule above, including the addition of the "C" program in the schedule, the grass is still going under severe stress and showing dry or "hot" spots, a change in your irrigation will be necessary. First, check to see if you are getting the proper coverage (head - to - head) with your system. If areas are not receiving proper coverage, call your irrigation company and ask them to immediately adjust your system. Second, change the primary "A" and "B" programs to a schedule of six or seven days per week. However, do not increase the time length each zone operates assuming the correct volume of water is normally being applied. Additional volumes of water will not solve the problem, but will create others. It is important to note that lawns with sufficient top soil will not normally experience these severe conditions. This condition will occur most frequently in very thin soils that cannot absorb or retain moisture easily due to their heavy clay content.
As soon as more favorable heat conditions occur, return to the original irrigation schedule. Do not over water!
NOTE:If your grass should go into the dormant stage (brown-out leaves), and do not have an irrigation system, requiring watering the lawn by a hose system, we recommend the following: (1) In order to maintain hydrated grass crowns and keep the growing point of the grass alive to allow for a full lawn recovery when more favorable moisture and temperatures return in the fall, Central MO Turf recommends watering each area of the lawn for approximately 45 minutes to one hour, early morning, once each week if measurable rain does not occur. (2) Generally speaking, lawns north of the Missouri River have much deeper top soil than areas south of the Missouri River. Much of this “southern area” has very thin or clay based soil with major rock formations below the top soil, which does not hold water well. Silt loam soils can store moisture longer and allows for a deeper penetration of the root zone. As a result of these improved soils north of the river, it may be possible to only water the lawn every two weeks instead of each week. However, this is something each homeowner must determine as a result of the condition of the lawn.
Please keep in mind there is no single right answer when it comes to watering a lawn. Soil depth, soil type, daytime temperatures, nighttime temperatures, humidity, type of grass, and natural moisture all play a role in determining the correct amount of moisture required and how often the moisture is required for the lawn. The recommendation above is simply a guide and adjustments may be required as conditions change. This information is especially important for people who do not have an irrigation system or their community restricts the amount of water used during the hot summer months.
A very easy way to test the volume of water being applied by the system is to purchase a few "rain gauges" at your local hardware store and scatter them around the area to be watered. Set the timer on the system at 10 minutes for each zone and check the gauges to determine the volume of water applied. If the volume applied is less than your desired amount of water, run the test again with a longer time setting. If the volume is more than your desired amount of water, run the test again with a shorter time setting.
One of the most important points of proper watering is to make sure you don't have localized dry spots in the lawn. This is soil that is so hard water will not penetrate it: thereby causing water to run off like water off of a ducks back. These areas must be dealt with and cured before even penetration of water will occur. We have all seen it before; we irrigate our lawn and we still have areas that dry out too fast. These areas wind up as brown dead areas when "summer stress" arrives. When you see these areas start to develop, give Central MO Turf Management a call as an application of gypsum will help these problems to be corrected.
Don't over water! Nothing could be more harmful. Plants and turf must have water to survive, but not too much. Roots do not chase water. Roots grow in the air spaces in the soil. When we over water, these critical air spores are filled with water, thereby depleting the oxygen supply and forcing the roots to the top of the soil where there won't be enough water for them to survive. Most of our summer fungus problems are enhanced by excess watering. An inch to 1 1/2 inches of water each week is sufficient for most turf conditions if applied properly. If water runs off the soil and does not penetrate the root zone, over watering will not be the answer. (Click here for more information about Organic Matter.)