(guest post by Valerie Smith)
Many of us lawn lovers want to keep our lawns in the best possible shape as the summer heat bears down on it. With that being said, it’s often tempting to water the grass more than it needs as a means of keeping it cool. Improper summer lawn watering practices can lead to two different, significant outcomes—drought from too little water and disease from overwatering. Read some of the most frequently asked questions we receive about proper irrigation practices that take place during the summer.
How much water does my lawn need during the summer?
Summer watering requirements for most warm and cool season grasses including zoysia, St. Augustine, bermuda grass, centipede grass, bluegrass and fescue require about 1-inch of water per week including rainfall. Some of you may be asking, “How do I measure 1-inch of water from my irrigation system or sprinkler?” A simple irrigation audit can help with a lot of this confusion.
In summary, an irrigation audit consists of setting a few inexpensive cups around different zones in your lawn. These cups can vary from empty cans of tuna to sprinkler gauges. Run your irrigation system or sprinkler until the cups hold about an inch of water. Different cups may have varying amounts of water, so it’s important to make adjustments so that your lawn receives a consistent amount of water throughout.
When should I water my lawn during the summer?
During the summer, temperatures rise, and soil conditions change. The best time to water your lawn in the summer is in the early mornings for longer periods of time and less frequently. This will decrease the dew period where a thin layer of dew sits on the blades of grass.
Despite the warmer temperatures, it’s important to decrease this period because it reduces the amount of time for water to sit on the grass blades—which is a useful disease management practice. Watering in the early mornings provides your lawn with water before it starts to get hot during the daytime.
How often should I water my lawn during the summer?
For most warm and cool season grasses, one or two waterings per week should meet the weekly 1-inch of water requirement. The amount of water each irrigation system or sprinkler delivers can play a huge factor in how often you should water the lawn.
Therefore, it’s important to set up an irrigation audit. This audit will inform you of how much water your lawn is receiving in a single watering. Make adjustments to the frequency of each irrigation period as needed.
For how long should I water my lawn during the summer?
Typically, most lawn irrigation periods during the summer should last between 25–30 minutes each. This amount of time depends on a lot of different factors though. As previously stated, each irrigation system or sprinkler can deliver different amounts of water and it’s important to hit that 1-inch per week requirement.
This can also depend on where the irrigation system is delivering the most amount of water and your lawn’s water holding capacity. For example, if you have really sandy soils, the water holding capacity for your lawn is probably pretty low because sand is very granular and it’s easy for the water to pass right through. In this case, you may need to water your lawn for longer periods or add more organic matter. If you have clay or loamy soils on the other hand, the water holding capacity is a little bit higher, so you should water your lawn in shorter periods to prevent waterlogged soils.
How do I know if my lawn needs more water?
Even with an irrigation audit, it can be hard to determine if your lawn is receiving enough water based on the different factors in the above section. If your lawn is receiving too little water, you may start to see signs of drought, which includes the thinning of grass blades that start to turn yellow or brown in color, and it may grow slower. It’s important to keep an eye out for this because this is the step right before it starts to die. Some lawns, like EMPIRE® Zoysia, may go into dormancy to preserve themselves before dying, but others may just die and can’t be revived.
It can sometimes get difficult to tell the difference between disease or drought because both include a yellow-brown discoloration of grass blades. If your lawn is being overwatered, the heat and over-saturation creates optimal environments for disease outbreaks. Yellow, discolored grass blades may also be a sign of chinch bugs, which love to feed on St. Augustine lawns.
Depending on the type of disease, oftentimes the key to distinguishing drought from disease outbreak is looking towards the edges of the discolored spots. Typical signs of disease vary depending on the type of fungus, but most signs include an interior clear dead zone where the fungus has killed the grass and a lighter yellow or brown ring around the outskirts where the fungus is spreading. Disease also usually appears in irregular, circle-shaped spots of varying size. This is a big indicator of disease damage.
Finally, check your soil. If the soil is damp, you’re probably overwatering the lawn. If it’s dry, damage is likely due to drought stress.
How do I keep my lawn cool in the summer?
As temperatures peak at this time, it’s often tempting to overwater lawns to keep them hydrated. This is not always recommended because it can cause disease outbreaks—especially if parts of the lawn are located in shady areas.
If the lawn seems to become too warm or starts accumulating scorched, brown spots as a result of the heat, consider adding a layer of top dressing to keep it shaded or cool. Be careful though—compost is black in color, so a lot of it can contribute to heating if a thick layer is left on top of the grass canopy for a long period of time. Excess use of top dressing can also smother the grass.
How do I keep new sod cool in the summer?
Watering new sod during the summer is different from watering an established lawn. For the first nine days (including the day of installation), you should water your lawn twice a day—once in the early morning and then again in the evenings. Once you’ve reached 10 days after installation, taper back your watering schedule to once per day. On day 13, you can reduce watering to once every other day and on day 16, begin transitioning to watering your lawn so that it receives 1-inch of water per week.
Keep an eye out for any disease outbreaks, especially if you have new sod in any shady areas. In newly laid sod, fungus tends to begin in individual pieces of sod and spread in an irregular circular pattern. If you see the dead/dying brown grass, your gut reaction might be to water the grass even more because you think it’s drying out. If this is in fact a fungus, watering your grass even more will actually make the situation worse. Fertilizing your newly installed lawn with the proper nutrients it needs is also important while you maintain an appropriate irrigation schedule.
The Lawnifi® New Lawn Starter Box is a box of three liquid fertilizer bottles that can be attached to the end of your garden hose during these watering periods. Each bottle of liquid fertilizer is designed to give your new lawn the nutrients it needs to establish roots. Want to learn more about achieving a great lawn? Check out more Sod University tips here.