For newly laid sod to become established, the soil on which it sits must be kept consistently moist for an extended period of time. When you are establishing newly laid sod, the necessary daily watering schedule for the first several weeks is gradually reduced to a regular schedule of only once or twice a week. During that initial window of intense irrigation, however, homeowners must keep watch for signs of fungus, which can thrive in such wet environments and devastate a new lawn. In this week’s Sod U blog, we discuss what signs of fungus to look for and how to treat fungus in a newly laid sod.
Truth be told, when a pallet of sod arrives at your home for installation, the greatest risk of death to your new lawn is from drying out, not from fungus. Think about it. When the sod arrives, it’s in a state of transplant shock; it’s just been scalped from its roots, palletized and wind-blown from being driven down the highway on the back of flatbed truck. It wants nothing more than the comfort of moist soil in which to sink its roots and a drink of cool water to take it out of shock. For this reason, it is suggested that you water your new sod twice a day for several weeks to help get it established.
However, it is during this period of intense irrigation that you also need to keep an eye out for fungus, which can thrive in such wet conditions, particularly in shady environments or during certain months of the year in regions with humid weather. You will more than likely spot fungus outbreaks in the shady areas of your landscape. If you are a homeowner with a lot of shade in your yard, it may be beneficial for you to read Growing Grass in Shaded Areas.
For more information on establishing a newly installed lawn such as details pertaining to watering and fertilization schedules, see Establishing a Newly Installed Lawn.
How to Identify Fungus in Newly Laid Sod
In newly laid sod, fungus tends to begin in individual pieces of sod and spread in an irregular circular pattern. At first, when you see the dead/dying brown grass, your gut reaction might be to water the grass even more because you think it is drying out. If this is in fact a fungus, watering your grass even more will actually make the situation worse. The key is to distinguish between the color and pattern of dead grass caused by drying out versus dead grass that is dying from a fungus outbreak. Typically, grass damaged by fungus will have an interior clear dead zone where the fungus has killed the grass, and a lighter yellow/brown ring around the outskirts where the fungus is spreading. A piece of sod that is drying out will dry out (turn brown) along the edges of individual pieces of sod or possibly over a larger area if you have an irrigation failure. You can see what dried out sod vs. sod damaged by fungus looks like in the images below.
Dried Out Sod
Pictured above are photos of individual pieces of sod drying out along the edges due to lack of water. Notice the color is a dry, straw color and the pattern takes a linear shape—it follows the edges of the sod pieces. This tends to happen if you haven’t conducted an irrigation audit to see which parts of your lawn are receiving the most/least amount of water during irrigation periods. It also commonly occurs when homeowners don’t place the pieces of sod tightly next to each other. During sod installation, it is ideal to place the pieces of sod together as tightly as possible to prevent weeds from pushing through the seams and to retain moisture.
Fungus in Newly Laid Sod
Pictured above are individual pieces of sod damaged by fungus with the fungus spreading to the surrounding pieces. Notice the color difference between the edges of the fungus (yellow-brown) and the clear brown, dead plant material in the center. Also notice that the pattern is not linear and does not conform to the edges to the pieces of sod like it does with an irrigation failure.
How to Get Rid of Fungus in Newly Laid Sod
1. Cut Back on Watering
The first thing you should do if you have a fungus in your newly laid sod is cut back on your watering. If it’s been a few weeks since you installed your lawn, you can begin to cut back on the watering for the entire lawn. If you have various zones in your irrigation system, you should cut back watering in the zone where the fungus damage is showing.
2. Spot Treat the Affected Area
Immediately spot treat the affected area with a topical/contact fungicide. As its name suggests, a topical fungicide works upon “contact” with the leaf blade. A simple, hose-end spray application can be used to spray the affected and surrounding areas of your lawn. Treat the affected areas every two weeks until the fungus stops spreading. A suggested product is a liquid topical fungicide that hooks right up the end of your garden hose: Spectracide Immunox Fungus + Insect Control.
3. Apply a Systemic Fungicide to the Entire Lawn
The next step we recommend is to apply a systematic fungicide to the entire lawn. If you see fungus in sections of your lawn, you need to be aggressive in treating both the specific areas of outbreak as well as your entire lawn to prevent further spread of the fungus. A systemic fungicide works by absorbing into the plant and circulating throughout the plant’s “system” to provide residual protection against fungus. Apply the systemic fungicide to your entire lawn (including the areas also treated with the topical, hose end sprayer). A suggested product is Heritage G Granular Fungicide. To learn more about the difference between systemic and contact/topical fungicides, read Lawn Disease Control Strategies as this blog discusses the importance of using a combination of different fungicides at the appropriate use rates.
Next Steps After Treating a Lawn Disease in Newly Laid Sod
Future Prevention of Fungus Outbreaks
Once you have rid your new lawn of this fungus outbreak, know that you must remain vigilant in treating for fungus preventatively every fall and spring. Since you have already had a fungus outbreak in your lawn, it is wise to go ahead and budget for a systemic fungicide like Heritage G every spring and every fall for prevention. The spring and fall temperatures are when outdoor temperatures and soil conditions start to alter, inviting the possibility of fungicide. In the spring, be sure to apply a fungicide in advance of any fertilizer, as nitrogen feeds fungus and can make a bad situation worse. For more information on the basics of lawn disease, read Lawn Disease Control.
Use a Fertilizer with Less Nitrogen
Lastly, consider employing a fertilizer regime that relies less on nitrogen throughout the year to provide you a healthy lawn. Although nitrogen is good for your lawn in proper amounts, it is also the ingredient in fertilizer that feeds fungus outbreaks. Consider the LawnifiTM New Lawn Starter Box, a liquid fertilizer program for that is designed to be used on newly installed and establishing sod. The New Lawn Starter Box contains everything newly seeded or sodded lawns need to establish thick, healthy grass including two bottles of Grow for improved soil health and one bottle of Maintain to feed the lawn. Lawnifi is powered by Catalyst TechnologyTM, which nano-sizes its nutrients so that more of them are absorbed through the roots and leaves. Since Lawnifi nano-sizes its nutrients, larger amounts of nutrients are efficiently delivered to plants. The amount of product that needs to be applied is significantly reduced while using 80 percent less nitrogen and yielding better results. Learn more about the proper fertilizer schedule for newly installed lawns in When to Fertilize Newly Installed Sod.
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