Select Page

Watch Out for these Common Lawn Diseases

The Florida Panhandle’s warm, humid, and sunny climate makes it ideal for lawns to stay lush and green for most of the year—but it’s also perfect for turfgrass diseases to develop. The summer weather has already been ramping up with temperatures reaching a little above 90 degrees Fahrenheit already this year which also means the signs of disease will be showing sooner rather than later. If you’ve been noticing large brown patches, thinning grass, or strange spots growing on you grass leaves, a disease may already be present. Here’s what you need to know to stay ahead of a total lawn takeover.

Large patch or rhizoctonia blight is one of the most common fungal turfgrass diseases to affect lawns, specifically if you have centipede turfgrass. This disease is most prevalent between the months of November and May, and if not controlled, will continue to spread in the fall. Symptoms are easy to spot, as large, brown circular discolorations that will grow larger in size over time. The best way to treat large patch is through preventative lawn maintenance over time. Water only when necessary to avoid excess moisture, apply slow-release appropriate lawn fertilizers, and clean your mower blades after each time you mow.

Large patch disease present in turfgrass. Photo Credit: Shelia Dunning, UF/IFAS Extension

Another common lawn disease to see during the warmer months is dollar spot. Dollar spot will affect all warm season turfgrasses but will be more commonly found in Bahia and Bermuda grass. Dollar spot disease creates small patches that are circular and will grow into larger areas. Individual grass leaves will have small lesions starting on the leaf margin that will have a light brown to tan coloration. It is important to know that grasses that are drought stressed, over irrigated, or mowed too low are more prone to contracting this disease. Proper cultivation practices are important to prevent dollar spot and other turfgrass diseases. For more sever cases, the use of chlorothalonil fungicide can be used during the treatment process.

There are various other lawn diseases that can be recognized over time. If you are trying to identify a potential disease in your lawn grass, consider using the UF Turfgrass Disease Identification Flowchart. It will walk you through the symptoms that are present to make a correct diagnosis. If you would like a more expert opinion, contact your local county Extension office for additional help. For additional information on turfgrass diseases, please visit:

https://sfyl.ifas.ufl.edu/media/sfylifasufledu/baker/docs/pdf/horticulture/TurfgrassDiseaseIdentificationGuide.pdf

https://gardeningsolutions.ifas.ufl.edu/lawns/problems-and-solutions/large-patch/ 

https://gardeningsolutions.ifas.ufl.edu/lawns/problems-and-solutions/lawn-diseases/

Doveweed Control in Centipedegrass Lawns & Landscaped Beds

Doveweed Control in Centipedegrass Lawns & Landscaped Beds

The Panhandle’s dreaded summer heat has finally arrived in force and has brought with it one of the most difficult to control lawn/landscape weeds, our annual enemy Doveweed (Murdannia nudiflora).  Doveweed is characterized as one of the world’s worst weeds due to its broad range of growing conditions, ability to root along its stems, forming mats as it grows, massive seed production (each plant can produce up to 2,000 seeds per year), and inconspicuous nature – it looks like a grass to the untrained eye.  So, what can gardeners do to control Doveweed that’s already up this year and prevent it next summer?  Let’s find out.

Doveweed emerging in a bare patch of a Centipedegrass lawn in late May 2025. Photo courtesy of Daniel Leonard.

First, the best prevention for all weeds, Doveweed included, is a healthy lawn/landscape.  Ensuring healthy, thick Centipedegrass turf and landscaped beds that don’t allow light to hit bare soil goes a long way towards reducing the overall weed load lawns and landscapes can experience.  For lawns, this can be achieved through mowing regularly at the proper height for your turfgrass (2.5” or so for Centipedegrass), irrigating no more than 0.75”-1” per week in the absence of rain, limiting stress from overfertilization, and removing excess thatch.  In landscapes, preventative weed control focuses on limiting overwatering/fertilization and maintaining a 2-3” organic mulch layer of pinestraw, pine bark, leaves, wood chips, etc.  Adopting these practices can greatly reduce the occurrence of weeds in your yard, however they will not eliminate weeds altogether and supplemental chemical weed control is often necessary.

Unlike Crabgrass, Florida Pusley, and other commonly encountered Panhandle annual weeds that emerge when the soil begins to warm in early spring (usually late February-March), Doveweed waits until mid-April-May (soil temperatures of 70-80 degrees F).  All these annual weeds are best controlled by preemergent herbicides, like Indaziflam (Specticle G), before seeds germinate.  For Doveweed, that means the first preemergent application should occur mid-April with a follow-up application 6-8 weeks later.  However, for this year that opportunity is behind us and our only option is post emergent herbicides.

Which postemergent herbicide you choose depends on if your Doveweed issue is in turfgrass or in landscaped beds.  In landscaped beds, the primary control option is either hand pulling or spot treating Doveweed with a 41% glyphosate product (Roundup and other generic products) at a rate of 3% (3-4oz glyphosate/gal).  As glyphosate is a non-selective herbicide, be sure to not get any overspray on any ornamental plant foliage.  In turfgrass, Doveweed control becomes a little more difficult.  You essentially have three options – atrazine, a generic 3-way broadleaf product, or a commercial grade broadleaf product.  Though it provides very good control of Doveweed and has pre-emergent properties to help discourage future weeds, I don’t prefer atrazine because it has a high potential to leach into groundwater following heavy rains in sandy soils, which describes much of the Panhandle.  The generic 3-way products (usually a mix of Dicamba, Mecoprop, and 2,4-D) are fairly effective on Doveweed, however follow-up applications are usually required and the 2-4D component can be harsh on Centipedegrass at the higher label rates required for Doveweed control.  Though somewhat expensive, the best post emergent option for most people is probably a commercial grade product like Celsius WG.  Celsius WG is a very strong post emergent broadleaf herbicide that is very effective on Doveweed and is also very safe on Centipedegrass, even in hot weather.  If the cost of the product (>$100) is off-putting, it is helpful to remember that even at the highest labelled rate, a 10 oz Celsius WG bottle goes a long way, enough to cover several acres of lawn. 

* Regardless of what method you choose, be sure to get after emerged Doveweed seedlings early, before they mature and begin flowering – even the strongest post emergent herbicides work better on young weeds. 

While Doveweed is a nasty little plant that is perfectly capable of taking over a lawn or landscaped bed, there are a variety of preventative and control options available.  Using a combination of the above techniques should help achieve lasting Doveweed controls in future seasons!  For more information about Doveweed and other summer annual weed control in lawns and landscapes, contact your local UF/IFAS Extension County office.

Watering to Establish a New Lawn

Watering to Establish a New Lawn

Lawn irrigation spray head running

Lawn irrigation spray head running. Credit: Larry Williams

When watering to establish a new lawn or when renovating areas within an older lawn, 2-3 “mists” throughout the day for the first 7-10 days until roots get established is recommended. These are 10-minute bursts. Then back off to once a day for about ½ hour for 7-10 days. Then go to 2-3 times a week for about 7 days. By then your lawn should be established.

Irrigation is not needed when we are getting adequate rainfall. Rain counts. In the absence of sufficient rain, you’ll need to provide enough water at the correct time to allow your new sod to root, hence the above directions.

A well designed and correctly installed irrigation system with a controller, operated correctly, helps to achieve uniform establishment. It can be difficult or impossible and inconvenient and time consuming to uniformly provide sufficient water to establish a lawn with hose-end sprinklers, especially with a sizeable lawn and during dry weather. Most people are not going to do the necessary job of pulling hoses around on a regular basis to result in a well-established lawn.

Too much water will result in rot, diseased roots and failure. Too little water will result in the sod, seedlings, sprigs or plugs drying excessively and failure to establish. The end result, will be a poorly established, sparse lawn with weeds, or complete failure.

There is no substitute or remedy for incorrect irrigation when establishing a new lawn or when renovating an older lawn.

It is risky to invest the required time and money if the new lawn cannot be irrigated correctly. Taking the gamble that adequate (not too much, not too little) rainfall will occur when needed to result in a beautiful, healthy, lush lawn is exactly that, a gamble.

An irrigation system is a good tool to supplement rainfall. As much as possible, learn to operate the irrigation controller using the “Manual” setting. It also is wise and is State law to have a rain shutoff device installed and operating correctly. The rain shutoff device overrides the controller when it is raining or when sufficient rainfall has occurred. A rain shutoff device is inexpensive and easily installed. Also, a rain gauge can be an inexpensive tool to help monitor how much rain you’ve received. Rain counts.

The above schedule should help when planting a lawn from seed, sprigs, plugs or sod.

Once the lawn is rooted, your goal change from establishing a root system to developing a deep, strong rooted lawn. To do this, irrigate to provide ½ to ¾ inch of water on an as needed basis. Here are links to a UF/IFAS video and publication with more info on how to do this: https://www.youtube.com/watch?v=W_wn-hwLNtg, https://edis.ifas.ufl.edu/publication/LH025.

Grass is Growing; Time for Mowing

Grass is Growing; Time for Mowing

Mowing a lawn.

Mowing a lawn. Photo Credit: University of Florida/IFAS

Mowing a lawn isn’t always as simple as making sure there’s gas in the mower. Lawns are alive, and treating turfgrass without care can cause problems in the long run. To make sure your lawn is healthy, follow these guidelines.

  • Know your turfgrass! Different grasses need to be mowed at different heights. Even the specific variety or cultivar can make a difference, but in general, bahiagrass should be cut to 3-4 inches, bermudagrass to ½ – 1½ inches, centipedegrass to 1½ – 2 inches, zoysiagrass to 2 – 2 ½ inches, and St. Augustinegrass to 2 ½ – 4 inches. Dwarf or finer-leaved varieties are usually cut lower and more often than taller grasses.
  • Mow regularly enough to avoid removing more than 1/3 of grass blade height at one time. This makes sure the plant is not overly stressed and can recover from mowing quickly and efficiently, as well as promoting deeper root systems.
  • Sharpen mower blades when they start to become dull. Freshly cut grass that has a ragged or torn appearance is a good sign that it’s time to sharpen the blade.
  • Pick up debris such as twigs before mowing to avoid damage to the mower blade.
  • Avoid mowing if grass is wet. Dew in the early morning or water from irrigation or rainfall will cause grass to clump and stick.
  • In uneven lawns, take care to avoid scalping grass when pushing a mower over inclined areas.
  • For a truly professional looking lawn, mow in different directions each time you mow. This can help to avoid forming wear patterns.
  • Leave clippings on the lawn rather than bagging them. Clippings break down over time, recycling nutrients and adding organic matter. Grass clippings typically do not contribute to thatch buildup. If clumps form, they can be broken up with a rake to evenly distribute the cut grass over the lawn.
  • Sweep clippings from hard, impervious surfaces to limit nutrient runoff.

Follow these guidelines and take care with other lawn management such as watering and irrigation, fertilization, and pest and disease control. You’ll have a great looking lawn before you know it!

Early Season Lawncare Practices

Early Season Lawncare Practices

Well folks, the earth has made yet another trip around the sun, and we find ourselves in another of hopefully many a new year. The weather has been cold, but it’s important that we spend a few moments plotting a strategy for our lawns in the coming year. Lawncare is a subject which is shrouded in myths and often misunderstood. Luckily, a little bit of knowledge can help you achieve stress free healthy turfgrasses.

Lifecycle

The first thing homeowners should understand is how turfgrass grows throughout the year. Turfgrass is split into warm and cool season species. You may have guessed that in the Florida Panhandle, warm season grasses are dominant. These grasses perform well in warmer weather going dormant when temperature begins to fall. During this dormant period, these grasses turn brown and may appear to have died. The grass itself is alive and well, but the roots have died back significantly.

Fertilizers

Why is this an important piece of information? There is no point in applying fertilizers to turfgrasses with no ability to absorb them. Instead, waiting until mid-April (think Tax Day) for fertilizers provides two key benefits. First, it allows time for the grass to develop a thick mat of roots. As roots are the main tissue for nutrient entry into plants allowing your lawn to utilize the applied nutrition. Second, waiting until a little later evades late season freezes. Cold weather may harm early season growth which stresses your lawn which could cause die back allowing weeds to take over.

Fertilizer spreader

UF/IFAS photo: GI-BMP

Weed Prevention

The subject of weeds brings us to a critical cultural practice in terms of lawncare. The application of preemergent herbicides. These herbicides are designed to create a barrier in the top 1/2 inch of soil which prevents shoot and root growth after weed seed germination.

Now, it’s important to understand, there are hundreds of thousands of weed seeds in the top layers of soil all over the world. Weeds take advantage of open spots in your lawn as does any plant in any ecological system.

A preemergent herbicide prevents weed from being able to fill those spaces, by preventing their growth. Given the proper watering and fertilization, your grass may now fill these voids. Your lawn will outcompete the weeds and become its own preventative.

Selecting and application of a pre-emergent herbicide does have some nuance. Not every product is compatible with every grass type, consult our Weed Management Guide to select a product that will work for your lawn. Another concern is application timing and frequency. Multiple applications will likely be required in the spring due to those triggers which break seed dormancy combined with product efficacy timelines. Local extension offices are a great resource for specificity, but generally application will need to be mid-February with a second application 6-8 weeks later based on the product label. Also important to note is that this is a long-term process.  It may take a few years of spring and fall application to eradicate the weeds in your lawn.

declining lawn

Lawn decline from weed infestation UF/IFAS Photo: Pawel Petelewicz

To Sum Up

Turfgrasses make excellent groundcovers and are look best when grown as stress free as possible. In the early parts of the year that entails holding off on fertilization and adding a layer of protection for summer weeds. Getting to know your turfgrass and familiarizing yourself with proper cultural practices will go a long way to making a healthy lush lawn. For more information you may read through our Florida Lawn Handbook or consult your local Extension Agent.

 

Water Management during Dry Weather

Water Management during Dry Weather

So far, our fall has been unusually dry with warmer temperatures. Even though our average annual rainfall is around sixty-two inches per year, we don’t always receive rain exactly when we need it. There are times when we need to apply additional water. During dry weather, employ the following water management practices to improve the water efficiency of your lawn and landscape.

Mulching helps conserve water. On bare ground, about sixty percent of the water can be lost through evaporation. A two to three-inch layer of mulch will help hold onto the water so the plants can use it. Try to mulch the entire root zone when possible or at least apply mulch all the way around the plants out to the end of the branches.

Lawn irrigation spray head operating

Irrigate on as needed basis during dry periods. Credit: Larry Williams

When watering, a thorough soaking to wet the soil to a depth of six to eight inches is much better for plants than light, frequent watering. Three to five gallons of water applied to one spot under the canopy of trees or shrubs should thoroughly saturate the root zone in that location. During dry periods, as a general rule), twenty-five percent of the root system, when watered thoroughly, can absorb all the water a plant requires at any given time.

When watering lawns, apply one inch of water per week when we are not getting rain. Although many sprinklers have irrigation rates of ¼ inch per hour, some may apply up to one inch per hour. Measure your irrigation rate and uniformity by placing several open-top containers of the same size under the sprinkler and see how long it takes to apply a known amount of water such as ½ inch.

An efficient irrigation program on turf should not begin until the lawn grass shows signs of moisture stress. Symptoms include a dull and bluish-green color and leaf blades folding. The most efficient time to irrigate is between sunset and sunrise because of less evaporation, less wind and lower temperatures. Early morning is the next most effective time to irrigate while midday is the least efficient.

Avoid fertilizing drought-stressed plants. Fertilizers are chemical salts and will dehydrate roots when water is in short supply. If you need to apply a pesticide, make certain the plant is not wilted at the time and spray during early morning or late afternoon. You should also avoid unnecessary pruning of plants during drought. Pruning encourages new growth, which has a high demand for water.

For more information on watering efficiently and drought tolerant plants, contact the UF/IFAS Extension Office in your county or visit the following website: http://gardeningsolutions.ifas.ufl.edu/care/irrigation.