How do we diagnose and treat large patch and take-all root rot in our HOA's St. Augustine common turf?

By OurHOA · General information · Revised October 29, 2026

How an HOA board tells large patch from take-all root rot in St. Augustine turf, gets a lab diagnosis, fixes watering and fertilizer, and times fungicides in TX and FL.

Part of the HOA board handbook: vendors, projects and upkeep.

The short answer

Brown circles in St. Augustine or zoysia common turf are often one of two fungal diseases: large patch, caused by Rhizoctonia solani, or take-all root rot, caused by Gaeumannomyces graminis. From the street they look alike. They need different timing, so the board's first spend should be a $35 lab sample, not a fungicide program. Large patch rots the base of the leaf in cool, wet weather. UF/IFAS says it is most likely from November through May, when temperatures stay below 80 degrees F, and it comes back where it struck before. Take-all rots the roots of stressed turf after long stretches of rain. By the time the leaves yellow, UF/IFAS says the fungus has been working on the roots for at least two to three weeks. For both, the fix that lasts is maintenance: less water, the right fertilizer and less stress. Fungicides work best as prevention on spots with a history, applied before symptoms. This guide is for Texas and Florida boards with warm-season turf; Colorado's bluegrass and fescue get different diseases. Rules vary by state and by your governing documents, and this is general education, not legal or agronomic advice.

Tell the two diseases apart

Walk to the edge of a patch, where yellow grass meets green, and do two things. Pull a blade. With large patch, UF/IFAS says the leaf comes off the stem easily and its base is a soft, dark rot that smells rotten. The roots are fine. Herbicide injury looks similar, but its leaf base is dry and tan with no smell. Dig up a runner. With take-all, the roots end up short, black and rotted, and stolons can carry black lesions. The fungus does not attack leaves, so yellow leaves mean the roots can no longer feed the plant. Then check the shape and the calendar: - Large patch: spots start about a foot across, turn yellow and then reddish brown or straw colored, and can grow to several feet. Rings of brown turf around green centers are common, and the active outer edge may look dark and wilted. A Williamson County AgriLife article describes Texas outbreaks in spring green-up and a return in fall. - Take-all: irregular yellow or light green patches from a few inches to a few feet across, thinning to bare soil if the rot continues. UF/IFAS ties it to Florida's summer and early fall rains. Williamson County AgriLife says Texas symptoms usually appear in spring and early summer. - Chinch bugs: hot, dry turf along pavement in summer. Our guide on chinch bugs in St. Augustine turf covers the flotation test that rules them in or out.

Send a sample before you spend

The Texas A&M AgriLife Plant Disease Diagnostic Lab charges $35 per routine sample, and turfgrass diseases fall under that fee. Its sampling page asks for two or three squares about 3 by 3 inches, with at least an inch of soil and roots attached, cut from the edges of affected areas. Include dying grass and grass that still looks healthy, never only dead turf. Refrigerate the samples until shipping and ship early in the week. In Florida, the UF/IFAS Plant Diagnostic Center in Gainesville runs a rapid turfgrass service with its own submission form, and your county Extension office can help collect the sample. Have the landscape contractor walk the property with whoever cuts the samples. Mark each patch on a site map and file the lab report with it. That map becomes next fall's treatment scope.

Fix the maintenance first

Both diseases feed on habits the board already pays for. Put these changes in the landscape contract and the irrigation schedule: - Water early and only when the turf needs it. UF/IFAS says to irrigate between 2 and 8 a.m., when dew is already on the grass, so leaves are not wet any longer than they have to be. Large patch infection starts when leaves stay wet for 48 hours or more. - Change the fertilizer. UF/IFAS says to avoid heavy nitrogen when large patch is likely and to use slow-release nitrogen. For take-all, it recommends equal amounts of nitrogen and potassium, slow-release forms of both, and no nitrate-nitrogen or uncoated urea. - Skip the lime. UF/IFAS says not to lime turf with take-all. - Cut back on weed killers. UF/IFAS warns that St. Augustinegrass is especially sensitive to herbicides, and even a correct application adds stress. - Mow sick areas last. Never remove more than a third of the leaf in one mowing, and have the crew wash clippings off the mower before moving to the next area, since mowers spread large patch. - Relieve compaction and wet spots. Williamson County AgriLife recommends hollow-tine aeration and a soil test before fertilizing for take-all, and lists poor drainage and over-fertilizing as large patch drivers. Our guide on cutting an HOA water bill with an irrigation audit covers finding the broken heads that keep zones wet.

Time the fungicide, or skip it

Fungicides stop the fungus from spreading. They do not grow grass back, and UF/IFAS says symptoms fade only after new leaves grow. Large patch. Treat where it showed up before, about two weeks before symptoms usually appear. UF/IFAS Gardening Solutions puts that at the end of September in North Florida and the end of October in South Florida. Williamson County AgriLife reports that Texas A&M turf specialists consider spring treatment not cost-effective because warm weather stops the disease, and advises an early fall application. Treating after symptoms appear may take repeat applications through winter. Take-all. UF/IFAS says fungicides work only as prevention and are less effective than cultural fixes once symptoms show. Start at least a month before symptoms normally appear, repeat monthly until the weather no longer favors the disease, and water each application lightly into the root zone right away. Williamson County AgriLife gives Texas owners the same advice in shorter form: treat an infested lawn in spring and fall, then water thoroughly. UF/IFAS lists azoxystrobin, propiconazole, pyraclostrobin, thiophanate-methyl and several others as options, and warns that some labels do not allow use on residential lawns. Ask the contractor to name the product and active ingredient in the bid and confirm the label covers your site.

Who may apply it

Texas. Occupations Code section 1951.003(a)(1)(B) counts identifying or treating pests or diseases of trees, shrubs or other plantings in a park or next to a residence, business or street, for pay, as the business of structural pest control. Section 1951.301 requires a structural pest control business license for that work, and the license holder must employ a certified commercial applicator. The section 1951.051 exemption covers people treating their own premises or an employer's. A resident volunteer spraying common turf does not clearly fit, so hire a licensed company and keep its Texas Department of Agriculture license number on file. Florida. Section 482.021 defines lawn and ornamental pest control as pest control on any lawn or ornamental, and pesticides include products aimed at fungi. Section 482.071 makes it unlawful to run a pest control business without a license. The section 482.156 limited certification held by many landscape crew members covers herbicides in plant beds and pest management on ornamental plants with handheld equipment. It does not mention lawns, so ask a landscaper who offers to treat turf for the company's pest control license. Under section 482.2265, a Florida applicator treating a lawn must post a weatherproof notice of at least 4 by 5 inches naming the business, and on request must give the customer the product name, active ingredient and label safety information.

A season plan, a notice and a motion

Sample year for a Gulf Coast Texas or central Florida community: - Spring: map every patch and send a lab sample if the cause is unclear. No large patch fungicide. - Late spring: fertilize with slow-release products once the grass is growing. Williamson County AgriLife says to wait until about three weeks after spring green-up. Resod dead areas only after the cause is fixed. - Summer: run the irrigation audit and move all cycles to early morning. In Florida, watch take-all spots after long rainy stretches. - Early fall: preventive fungicide on the mapped large patch spots, timed to your region. - Fall and winter: hold back nitrogen, and keep mowing sick areas last. Notice the board can post: "On [date], a licensed contractor will apply a fungicide to the common turf at [locations] to control a turf disease. Please keep children and pets off the treated areas until the product has dried, as the label directs. Questions go to [contact]." Motion: "Move to approve [contractor], license number [number], to apply [product] to the turf disease areas marked on the attached map during [month], at a cost not to exceed $[amount], and to add the attached watering and fertilizer changes to the landscape contract."

Mistakes boards make

- Spraying large patch in spring because that is when it looks worst. Book the fall application instead. - Approving a whole-property program when the map shows four spots. - Resodding a patch while the zone stays wet and overfed. - Letting a resident with a hose-end sprayer handle it. The board owns that liability. - Calling every brown spot a fungus. Drought, herbicide injury and chinch bugs leave similar patches, and a $35 sample settles it. Our guide on hiring an HOA landscaping contractor covers writing watering and fertilizer duties into the scope, so these fixes outlast the next crew change.

Sources

These guides are general education for HOA boards and residents, not legal, tax, or financial advice. Rules vary by state and by your community's governing documents - check with a professional for your situation.

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