Use a low-nitrogen, slow-release fertilizer. We’ve got the answers! Copyright © 2021 Clemson UniversityClemson Cooperative Extension | 103 Barre Hall Clemson, SC 29634864-986-4310 | Contact UsHGIC@clemson.edu, Brown Patch & Large Patch Diseases of Lawns, College of Agriculture, Forestry and Life Sciences, Centipedegrass Yearly Maintenance Program, Pillar G Intrinsic Fungicide (Granules, 0.38% with triticonazole, 0.43%), Fame Granular Fungicide (Granules, 0.25%), Lesco T-Storm 2G Fungicide (granules, 2.08%), Bayer Advanced Fungus Control for Lawns RTS, Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate (1.55%; apply with hose-end sprayer), Lebanon Turf Fungicide Bayleton 1G (Granules, 1%). Mancozeb Fungicide or Chlortan720 Fungicide – Spray to fix the problem. If you see Grey Leaf Spot in your lawn it is best to treat straight away to avoid/limit the spread. The fungus survives dry summer conditions as fungal mycelium and spores on dead foliage and in the thatch layer. This generally means one time per week with one inch of water. The disease cycle could start from spots or lesions on grass blades and progress onto rot or death of the plant known as melting out. ›. Melting out is a different disease also caused by fungi in the same group. Spring and early summer applications of fungicide can be effective, but little can be done to reverse lawn disease once the melting-out phase begins. Most yards need only 1-inch (2.54 centimeters) of water weekly, but homeowners... 2. Use fungicide treatments as needed along with proper turfgrass culture. During this part of the leaf spot lawn disease, the grass takes on a brown under cast making it appear underfed or dried out. It’s caused by several different fungi that kill the grass when the weather warms up. Water no more than once per week and soak the soil to a depth of 6”. Cause and Symptoms: Gray leaf spot develops rapidly with abundant moisture and warm temperatures on St. Augustine grass. Leaf spot generally starts in cool weather but can occur at any time. Learn more about… Mowing and Watering Mushroom Necrotic Ring Spot. Fungal leaf spots will remain on the affected leaves until the grass grows out and is mowed down. Table 1. Development Factors. What’s similar in the grass diseases of this family is that they give your lawn a real one-two punch by creating the leaf spot phase in the spring and fall but changing gears into a sheath and root rot phase during the heat of summer. Follow all directions, precautions and restrictions that are listed. See Table 1. Blades of grass will wither and die if leaf spots are numerous. Leaf Spot This grass fungus is caused by Bipolaris sorokiniana. When spring temperatures reach 55 to 60 degrees and there is a lot of moisture from rain or dew, the fungus begins to grow and spreads its spores by wind and water. Leaf spot disease — or melting out disease as it’s sometimes called — is a common lawn disease that is caused by different fungal organisms from the Helminthosporium species. Enter yourNeighborhood Gray leaf spot of St. Augustinegrass is a disease caused by a fungus that is common during extended periods of hot, humid weather. The most common times are when the host (turfgrass) is under stress. Symptoms are small reddish brown, oval lesions which coalese resulting in an overall reddish cast to affected turf. Enter yourNeighborhood Discount Code. The melting-out phase begins during hot, dry weather and causes large irregular areas to appear dried out. Scotts® DiseaseEx™ Lawn Fungicide offers a formula to cover a wide range of problem lawn diseases. Treatment for leaf spot lawn disease may be required every 3–4 weeks to gain control. Under favorable conditions for disease development, large areas of turf may appear to be scorched, resembling extreme drought stress. Newly sprigged, sodded, or rapidly growing grass is more susceptible than well-established grass. Apply to affected areas, keeping in mind that you could apply to surrounding areas to try to prevent spread of the disease. Under these conditions, the disease causes serious thinning of the turf. Call 281-431-7441 for more information. https://getlawnstar.com/blog/lawn-fungus-identification-guide Very knowledgeable and very friendly. 4. Did you receive a mailing or email from us? Affects: Wintergrass, Bentgrass, Kentucky Bluegrass, RTF Fescue, Nullarbor Couch Description: A fungal disease likely to strike during warm, humid conditions. Remember: Leaf spot makes turf look sick, but does little permanent damage. Foliar and root diseases can affect both warm- and cool-season grasses. Joey Williamson, PhD, HGIC Horticulture Extension Agent, Clemson University. As with all lawn diseases, how the turf is watered, fed and mowed makes a huge difference. Leaf spot makes turf look sick, but does little permanent damage. Water your lawn only when necessary. This fungal disease not only affects the leaves, it could also damage the root and the crown of Zoysia grass. Always irrigate in the morning, which promotes quick drying of the foliage. Irrigate deeply, but infrequently. Leaf Spot (How to Treat Lawn Disease Early) Symptoms: Grass turns brown in irregular patches from 2 inches to 2 feet across. Even though leaf spot does not do significant damage to the turf during this phase, it sets the stage for the much more serious melting-out phase. Leaf spot and melting out diseases are common on most sward situations. Description: A fungal disease occurring in warm and wet conditions. Discount Code. Proper Care For cool-season grasses, follow the proper care for your lawn during the summer and then core aerate and overseed in the late summer to early fall with leaf spot resistant seed. Enter your address to find available services. 2 RTS = A ready-to-spray hose-end product. Lawn treatment services, if needed, should begin early. In residential settings, these diseases can severely reduce the aesthetic appeal of a lawn and can lead to expensive lawn replacements. Leaf spot is another disease that could damage Zoysia grass. Leaf spot disease thrives in warm weather and causes spots that are purplish in color to appear on grass leaves. Control: Spray with Mancozeb fungicide. Disease-causing fungi are almost always present in the soil, waiting for a time when conditions are right to attack. Leaf Spot is a fungal disease characterized by grass blades having small oval spots with straw-colored centers and maroon borders. Leaf spots on grass blades are tan to gray with purple to brown margins. Preventing Lawn Fungus 1. It is especially troublesome in shaded areas that remain damp for some time. Melting out occurs in hot weather and can be easily confused with drought stress or insect damage. Helminthosporium diseases of turf are a group of common, cool season turfgrass diseases (including Helminthosporium leaf spot and melting out) that occur throughout North America. Open the area around the grass crowns (where the plant goes through the thatch and into the soil) with core aeration. Regular lawn fertilizing and aeration can go far towards disease prevention. Gray leaf spot is favored when temperatures are between 77 and 86 °F during the day and above 65 °F at night, and is most severe during rainy, humid periods. Daconil is the best fungicide for lawns. This helps prevent the spread of leaf spot spores. This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. Bin-Die Selective Lawn Weed Killer 2L; Apparent Halosulfuron 750 WG 25gm Nutgrass Mullumbimby Couch Killer; Lawn Pride COLOURMAXX 125mL $33.00; Acelepryn GR Turf Insecticide 10kg; Lawn Grubs & Pests; Grey Leaf Spot; Lawn Health Checks; Lawn Mowing Tips; Watering New Turf; Lawn Aeration; Garden Easi Planter Boxes; News Menu Toggle. Individual blades are often girdled and die giving the appearance of drought stress. Leaf Spot. Grey Leaf Spot Fungus can devastate a lawn, killing the entire blade of grass, and if left untreated, it can make its way all the to the runner, killing off sections of grass. On St. Augustinegrass the initial leaf spots are small and brown, but they expand rapidly into large, oval or elongate, tan to gray leaf spots, which are surrounded by purple or brown borders. Join our mailing list to receive the latest updates from HGIC. There may not be any distinctly visible lawn disease symptoms during the melting out phase, as the damaged areas may appear very similar to the effects of dry weather or insect injury. As the weather warms, the disease moves into the second phase of melting out. Grey Leaf Spot Fungus can devastate a lawn, killing the entire blade of grass, and if left untreated, it can make its way all the to the runner, killing off sections of grass. Did you receive a mailing or email from us? During the leaf spot phase of this lawn disease (spring or fall), individual grass blades will have large numbers of lesions (or infection marks) that appear a little like a cigarette burn, a dark circle with a tan spot in the center. During warm, humid weather the fungus produces a grayish mycelium (cottony fungal growth) and numerous spores on dying foliage, which gives a grayish appearance to the spots. Spotted leaves occur when fungal spores in the air find a warm, wet, plant surface to cling to. Melting out and leaf spot are usually mentioned together. For more information on proper St. Augustinegrass care, see HGIC 1218, St. Augustinegrass Maintenance Calendar and on other turfgrass diseases, see HGIC 2152, Leaf Diseases of Lawns, and HGIC 2150, Brown Patch & Large Patch Diseases of Lawns. Water in the morning so turf can dry out quickly. COVID-19 Extension Updates and Resources ... More Information », Factsheet | HGIC 2151 | Updated: Sep 11, 2019 | Print | Download (PDF), Gray leaf spot of St. Augustinegrass caused by Pyricularia grisea. DOW Eagle 20EW is my first option in terms of lawn … Limb up over-hanging trees and prune back nearby shrubs. Daconil Ultrex Turf Care Fungicide. However, it sets the stage for the more serious melting-out phase of the disease. Although primarily a disease of St. Augustinegrass, it also attacks centipedegrass and many ryegrasses. Helminthosporium (now that’s a mouthful!) Turfgrass tall fescue may also be damaged by gray leaf spot. All recommendations are for South Carolina conditions and may not apply to other areas. This new product is fast acting and continues to control lawns diseases for up to 4 weeks. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Many conditions can cause patches of brown, dead grass on your lawn, but only one gets the official name brown patch. It is caused by a fungus called Bipolaris sorokiniana. When favorable conditions of moisture and high humidity return during the summer, the fungus produces an abundance of spores that are spread by wind, splashing rainfall or irrigation, and the movement of lawn equipment on wet grass. Bag and dispose of grass clippings if disease is present. Photo by Lane P. Tredway, University of Georgia, Athens, GA. Gray leaf spot is a fungal disease (caused by Pyricularia grisea) that occurs most commonly on St. Augustinegrass (Stenotaphrum secundatum), but occasionally may also be found infecting tall fescue, bermudagrass, centipedegrass and ryegrass in home lawns. Use pesticides only according to the directions on the label. It’s best to be sure the grass does not stay continuously wet or become excessively dry. However, it sets the stage for the more serious... Water in the morning so turf can dry out quickly. Improve air circulation and light level on lawn. The disease occurs in randomly distributed, irregularly shaped patches. The excess forage that keeps moisture within the canopy and prevents sunshine and air movement creates optimal conditions for an infestation. “Charlestongrass”) and ryegrass. In addition to heat and humidity, the main factors inviting brown patch are excessive nitrogen and irrigation, which means that very lush and gree… If left untreated, it can travel down the blade of grass and cause the roots to rot. Leaf spot / melting out is one of several Helminthosporium diseases which survive in thatch during periods that are unfavorable for disease development. If this document didn’t answer your questions, please contact HGIC at hgic@clemson.edu or 1-888-656-9988. Whenever you have a question on leaf spot (or any other lawn disease) contact your neighborhood Spring-Green. These fungi are most active during periods of cool (60-65°F) and wet weather, but some are able to cause disease whenever temperatures are above freezing. Infected areas are reddish/brown turning to yellow and light brown and occur in patches. Water in the morning so the grass will not remain wet for long periods. Fungal infections can occur due to either under- or over-fertilization. Leaf Spot Disease Leaf spot is caused by a specific type of lawn fungus, and occurs predominantly in the spring when there is a lot of succulent new growth that doesn’t have the chance to harden off. Both diseases occur when dry weather alternates with cloudy, wet periods and during cool to moderate temperatures. The lawn disease fungi survive the winter as spores (fungus seeds) and as mycelium (fungus strands) in and on diseased turf tissue. During infestation, these spots widen and develop tan centers, killing the grass blade above its root. This can be followed by a process known as a “melting out” phase. Treat it using high-quality fungicides, including thiophanate-methyl and azoxystrobin. Athracnose. Avoid medium to high nitrogen fertilizer levels. 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