Discolored, brown patches of grass are not a good sign! If you see brown spots in your yard, you will probably have to replace or over seed the area simply because brown grass usually means dead grass. However, identifying the problem can help stop the damage, decreasing the chance of a total loss. The most common causes of browning in your lawn are (A) Lack of Water, (B) Pet Urine, and (C) Brown Patch (a fungal growth).
Lack of Water
The most common time we see sod browning from lack of water is within the first few weeks after installation. If your sod has not received enough water within the first few days after it was installed, you will notice gaps in the seams of your sod with blades that have browned all the way through and will sometimes be rolled up along the edges (see photo below). The sod will have a crisp feel to it, and it will typically be brown in large patches that seem to have died all at once. When sod has browned from a lack of water you will need to replace the sections that are dead with new sod OR over seed those areas in the fall. To ensure your sod is getting enough water, water it as it is being installed and every day thereafter for two weeks. It is best to water in the morning for at least an hour OR however it takes for an inch of water to douse the area. After two weeks you can cut back watering to a few times a week and then as needed. The links below give more detail about caring for your sod for the first few weeks after installation.
Pet urine is another likely culprit for brown spots in your grass. These spots are, more often than not, very round, smaller areas of grass that seem to die all at once (see photo below). Dogs tend to eliminate in the same location creating a localized section of high salt levels that saturate the sod's roots, killing the root system. Dousing the area with water after your pet uses that spot AND letting your pet drink more water to dilute the salt levels in the urine will help;however it is ideal to encourage the dog to use a different area when relieving itself. Before you replace the sod or over seed the dead/browning area, you will want to dig up and replace the soil beneath the grass to remove the leftover salts in the soil.
Brown Patch/Fungal Growth
A fungal growth, appropriately named Brown Patch, is another very common reason we get calls about brown patches in customers yards. Brown Patch is characterized by splotchy brown spots, usually irregular in shape (see photos below). The browning will happen inconsistently within the patch itself. You will notice that some of the infected blades still show some green in them, and that each blade within the patch will not brown at the same rate. These areas grow very rapidly so it is necessary to address this issue as soon as you suspect a fungal growth. If the fungal growth goes untreated the patch will die completely in time. If you suspect Brown Patch, immediately purchase a spray on fungicide and follow the application instructions on the label. Fungicides can also be used as a preventative, assisting at keeping fungus growth at bay for up to 28 days. ( Purchase Fungicide Here ) If your lawn succumbs to a fungus, these areas will need to be re sodded or over seeded. To prevent fungal growth, be sure to always water your sod in the earliest part of the morning as possible. Warm, humid, summer evenings tend to be the ideal conditions for fungus to grow.