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.
Do you have a low-growing weed that is producing tufts of white, fluffy, dandelion-like seeds, which float in the wind when disturbed or mowed? This is Annual Trampweed (Facelis retusa). I did not see this weed in North Florida until recent years. It’s native to South America.
Mid-April to early May is the time of year when this winter annual weed goes to seed in North Florida. That’s what it is doing now and it is a prolific seed producer. Each white tuft contains numerous seeds. Each tiny seed is attached to a small individual bristle, coming out of the larger tuft, which is carried by wind. This allows hundreds of seeds to move to other locations.
Trampweed is approaching the end of its life as we move into early May. As a winter annual, the individual weed dies in response to warm temperatures only to leave behind hundreds of seeds that survive the summer. These same seeds come up the following fall to early winter to begin the next generation. The best time to attempt chemical control with an herbicide is well before these weeds mature and begin flowering.
Trampweed in bloom. Credit: Larry Williams
One chemical control option is to apply a lawn preemergence herbicide during October when nighttime temperatures drop to 55° to 60°F for several consecutive nights. This will be just before these winter annual weeds emerge. Done correctly, the application of a preemergence herbicide forms a temporary chemical barrier along the soil surface preventing the winter annual weeds from emerging. Hence the name preemergence.
A second application of preemergence herbicide may be required six to nine weeks after the initial application to achieve season-long control, based on the product’s label directions.
If you miss this narrow window of opportunity to apply a preemergence herbicide, watch for the small young weeds in winter and treat then with a postemergence herbicide that is labelled for use in the type of lawn grass you are growing.
Waiting until trampweed is producing flowers and seeds in April and May to attempt control is almost worthless in controlling this weed. Correct timing is critical.
Trampweed usually is found in areas of a lawn that are already weak and thinning. It favors open, dry, stressed and low-fertility areas of a lawn. So, try to manage your lawn correctly. This involves learning to mow, irrigate and fertilize correctly for the type of lawn grass you are growing.
The thistle has long been an enemy of ranchers, county roadside maintenance crews and homeowners. Often difficult to control, it causes both headaches for producers, in reduction of grazing for livestock as well as being an eyesore for gardening enthusiasts. There are nine different species of thistle in Florida. Most of these are closely related, therefore the control protocols are the same. Only one species is a perennial, and all others are biennial. A biennial plant grows from seed in one year and produces seed for the next.
Thistle that has begun to bolt. Photo Credit: Dr. Jason Ferrell, University of Florida/IFAS Agronomy Department-Weed Science.
It’s important to understand the biology of the thistle in regards of seeking control of this fast spreading weed. This plant will grow a taproot and a cluster of leaves in the first year. This is known as the rosette stage. In the second year, a stalk will appear from the center of the rosette. This is called “bolting”. A seed head will form once the bolting stage is complete. Amazingly, one thistle plant can amass 4,000 seeds. The plant faces its demise after releasing the seeds. The rosette growth stage is mostly during the winter months with bolting occurring from January to July. This is important to note when battling this persistent weed.
As for control, preventing the thistle from producing seed is the most important management measure. Otherwise, little can be done to stop the outbreak of the weed. For homeowners, manually removing the rosette and tap root by hand is effective with small stands. Be careful and wear protective coverings on your hands and arms. Keep in mind, the plant will come back if the tap root is not fully removed.
Other physical control methods, like mowing, have mixed results. This can be effective if mowing occurs after the bolting stage has occurred, but before the seed head forms. However, this is tricky, as thistle plants often do not bloom at the same time.
Thistles in the rosette stage are very susceptible to herbicides. Although, applying a herbicide after the seed head has formed has little effect on control. Herbicides containing 2,4-D are very effective for landscapes. Timing of application is critical. The key to controlling this weed is by scouting and identifying stands as early as possible.
If you’re a beekeeper, there is an upside to this weed. Delicious honey can be made from the thistle bloom.
Supporting information for this article can be found in the UF/IFAS EDIS Publication, “Thistle Control in Pastures” by Dr. Brent Sellers and Dr. Jason Ferrell.
UF/IFAS Extension is an Equal Opportunity Institution.
Over the last decade or so, the Panhandle has been overrun, and I don’t just mean by the summer beach traffic. Rather, by an aggressive, exotic perennial grass that quickly displaces all native species, is not useful as a forage to wildlife or livestock, can spread by roots or seeds, and has no natural enemies. If you own property in the Panhandle or spend any amount of time on its roads, chances are you have become acquainted with this worst of invasive species, Cogongrass (Imperata cylindrica).
A native of Southeast Asia, cogongrass was introduced into the US in 1912 around Mobile, AL as a hitchhiker in orange crate packing. Then the 1920s, 30s, and 40s, it was intentionally introduced from the Philippines into other Gulf Coast states, including Florida, as a potential pasture forage for livestock. Since then, cogongrass has become one of the most economically and ecologically important invasive species in the US and worldwide, infesting nearly 500 million acres and is now found on every continent.
Cogongrass in Calhoun County, FL. Photo courtesy of Daniel Leonard.
Cogongrass is easily identified in late spring, when the grass throws easily spotted fluffy, white-colored seedheads above the mats of grass beneath. Additionally, patches of cogongrass are almost always noticeably circular in nature, radiating out indefinitely from the initial infestation. A closer inspection of the grass will reveal light green leaves up to 4’ in length, with an off-center, silvery colored midrib (the primary leaf vein that runs from the base of the leaf to the tip) and serrated leaf edges. Underground, cogongrass exhibits a dense underground root system that can reach as deep as 4’. This feature is the primary reason cogongrass outcompetes other plants, withstands any drought, fire, or soil condition thrown at it, aids in its resistance to herbicide activity, and generally makes it very difficult to manage.
The first step in managing cogongrass is prevention. If your property or the property you manage doesn’t have cogongrass, do everything you can to keep it that way. While the species can spread distances through seed dispersal, it is much more frequently moved around by fragmented rhizomes hitching a ride on equipment. If you or a contractor you’ve hired are working in or around an area with cogongrass present, avoid disturbing it with equipment and be diligent in monitoring the site for outbreaks following the job’s completion.
If you find cogongrass on your property, effectively eradicating it requires patience, persistence, and several years’ worth of herbicide applications. Currently, of the hundreds of herbicides available for purchase, only two chemistries have been proven to be very effective in destroying cogongrass, impazapyr (Arsenal, Stalker, etc.) and glyphosate (Roundup, Cornerstone, etc.).
Imazapyr is an extremely effective non-selective, residual herbicide that controls a wide variety of weed species, including cogongrass. Just one or two applications of imazapyr can provide 18-24 months of effective cogongrass control, with follow up treatments required as needed after that. However, Imazapyr has a major downside that limits its use in many settings. Because it is a non-selective herbicide with significant soil residual activity, it cannot be used around the root zones of desirable plants. Oaks, other hardwood trees, and most landscape plants are especially sensitive to imazapyr. This herbicide is best limited to use in fields, waste/fallow areas, natural areas, and monoculture pine plantations – it is not appropriate in most residential and commercial landscapes.
The other option, glyphosate is a non-selective herbicide with no soil residual activity. It is often a better option where severe injury or death of desirable hardwood trees and ornamental plants cannot be tolerated. However, due to its lack of residual soil activity, glyphosate applications on cogongrass patches will need to be repeated on an annual or biannual basis for up to five years for eradication of the infestation.
*Regardless of which herbicide you choose, controlling cogongrass is a multi-year affair requiring diligence and patience.
For more information on cogongrass and for specific herbicide recommendations and application rates/timing for your site, please contact your local UF/IFAS County Extension Office.
Hot, summer months are not the time to be using most lawn herbicides.
One issue is the heat of summer. Most lawn herbicide labels include statements such as the following.
“Do not apply when temperature exceeds 90°F.” “Do not broadcast apply this product when air temperatures are above 90°F (85°F for St. Augustinegrass) unless temporary turf injury can be tolerated.”
Every year we’ll see lawns that are injured or killed because of lawn herbicides being applied when temperatures are too hot.
Summer is usually a rainy and windy time of the year. Many lawn herbicide labels include statements such as the following.
“Allow 12 hours after application before watering lawn for maximum effectives on listed weeds.” “Apply only when wind is no more than 10 mph.” “Applying this product in calm weather when rain is not predicted for the next 24 hours will help to ensure that wind or rain does not blow or wash pesticide off the treatment area.”
It is critical to read and follow the label directions and precautions for any pesticide you use. Pesticide labels, including herbicides, include the following statements.
“To the extent consistent with applicable law, the buyer assumes all risks of use, storage, or handling of this product not in accordance with label directions.” “It is a violation of Federal law to use this product in a manner inconsistent with its labeling.”
Crabgrass growing in centipedegrass lawn. Photo credit: UF/IFAS Extension
By the time summer arrives, many of the lawn weeds are mature, which means they are well established with extensive root systems. These mature, well established weeds are much more difficult to control. They are more susceptible to herbicides when they are small, young, and not well established. Also, these mature weeds have been allowed to produce countless numbers of seeds as they move into summer. Most weeds are prolific seed producers. For example, a single crabgrass plant (a common summer lawn weed) can produce 150,000 seeds.
Applying a preemergence lawn herbicide in February to help prevent summer annual weeds such as crabgrass or applying a postemergence lawn herbicide during spring while the weather is mild and before the weeds are out of control simply makes more sense than waiting until summer.
The best options now with lawn weed control involve continuing to follow good mowing practices, maybe hand removal of some weeds, and just simply waiting it out until next February and spring to worry with the use of lawn herbicides.
In the meantime, you may want to read the following UF/IFAS Extension publication on lawn weed control.
