If it looks like the aliens have landed in your St. Augustine lawn, you might have large patch. Large patch manifests as large, brown patches and is common in St. Augustinegrass lawns. With a little prevention and the proper treatment, you can get rid of this fungal invasion and restore order in your lawn.<\/p>
Large patch is a fungal disease<\/a> caused by a strain of the fungus Rhizoctonia solani<\/em>. This fungus lives in the soil and affects warm-season turfgrass during the spring and fall transitional periods. If you\u2019ve heard about brown patch in warm-season lawns, it\u2019s the same disease. Large patch used to be called brown patch until experts renamed it recently.<\/p> Before you decide to treat these spots on your lawn, it\u2019s best to get an official diagnosis. Take a sample of the affected area to your Cooperative Extension office to get a positive ID before you move forward with treatment.<\/p> Nearly all fungi thrive in damp, wet conditions. The conditions below encourage large patch in St. Augustinegrass lawns.<\/p> The good news is that some of these conditions are under your control.<\/p> The best way to prevent large patch, or at least lessen the severity of it, is proper lawn maintenance. In other words, continue to do the things you already do, but do them correctly and at the right time. <\/p> Water:<\/strong> Water before 8 a.m.<\/a> and only if<\/em> your lawn is showing signs that it needs water. When one-third to one-half<\/a> of the lawn starts to look stressed, turn on the sprinklers.<\/p> Signs it\u2019s time to water:<\/p> Fertilize:<\/strong> Avoid fertilizing the lawn during fall and spring. Wait until early summer (or late spring) to apply fertilizer only if<\/em> your soil test recommends it. According to the University of Florida, over-fertilizing the lawn<\/a> with nitrogen can cause repeated fungal outbreaks (along with overwatering). <\/p> Mow:<\/strong> Mowing won’t prevent this fungus from attacking your lawn, but it can help prevent it from getting worse<\/a>. <\/p> Mowing tips:<\/p> Dethatch:<\/strong> If your thatch layer is greater than 1 inch<\/a>, consider dethatching. Dethatching removes excess material from the surface of the soil so that air, water, and fertilizer can reach the soil surface. Do this in late spring or early summer. <\/p> You can rent a machine or buy a liquid biological dethatcher to help break down the excess thatch. If you have a very small area, a manual dethatching rake works, too.<\/p> Aerate:<\/strong> If your soil is compacted, aeration<\/a> is a means to open up the soil and allow more air and water to circulate. Aeration machines pull plugs from the soil, allowing air, water, and nutrients to reach the grass. The result is stronger, healthier roots and a more beautiful lawn.<\/p> Once you\u2019ve properly identified the disease and corrected your cultural practices, you can consider whether additional treatments are necessary. If so, here are a few natural and chemical solutions to consider.<\/p> Natural solutions:<\/strong> The active ingredient bacillus amyloliquefaciens strain D747 is marketed as effective against brown patch disease. Since large patch is caused by the same bacteria (albeit a different strain), this may be worth a try on large patch, as well. You can find these products online or at a local store. Most will market them as suitable for organic gardening.<\/p> Chemical solutions:<\/strong> If you\u2019ve had problems with large patch in the last transitional season, it\u2019s best to use preventative treatment since you\u2019ll likely have another outbreak next spring or fall. Ask your local Extension agent (or search their fact bulletins online) to find the best time to apply preventive chemicals in your state. With preventive applications, timing is key, so be sure to get the timing right for the best results.<\/p> As with most chemicals, alternate between two, or use a product with more than one active ingredient, to keep your lawn from building a resistance. Azoxystrobin with propiconazole, pyraclostrobin with triticonazole, and fluoxastrobin are highly effective against large patch<\/a>.<\/p> A word of caution<\/strong>: Since warm-season grasses grow more slowly in the shoulder seasons, don\u2019t expect the fungicides magically to turn the lawn green again. The chemicals simply prevent the fungus from expanding<\/strong>. The only way to turn the lawn green again is to wait until it grows new leaves (or paint it<\/a> in the meantime).<\/p> There are many other reasons<\/a> why your St. Augustine lawn may have brown spots. According to the University of Florida\u2019s IFAS Extension service, there are a few St. Augustine cultivars that are more susceptible to large patch than others. If you\u2019re starting from scratch and have had issues in the past, avoid choosing a cultivar that is susceptible to this disease. Yes<\/a>, all warm-season grasses are affected, including bermudagrass. However, with bermudagrass<\/a>, the damage may not be as noticeable because of its quick growth habit. <\/p> <\/div> <\/div> If this latest fungal invasion has taken you to the outer limits, <\/em>contact a local lawn care professional<\/em><\/a> to bring your lawn back into focus.<\/em><\/p> Signs you have large patch<\/span><\/h2>
Conditions that lead to large patch<\/span><\/h2>
How to prevent large patch<\/span><\/h2>
How to get rid of large patch<\/span><\/h2>
FAQ<\/span><\/h2>