As we continue to tend to our summer landscapes and gardens, it is important to have a proper weed control plan in place. Unwanted plants that grow in your garden or landscape can cause for poor germination rates and poor quality of your crop. Weeds deprive your plants from essential nutrients, water, and sunlight that they need to thrive. There are many methods of weed control, but it important to make decisions based on what control method will work best for you.
Taking Soil Tests and Fertilizing are a good place to start in your plan for weed control. Unwanted plants thrive in low quality soil while your plants perform poorly. On the other hand, over fertilizing can cause for an increase in weed pressure. Knowing your pH and nutrient levels are essential to weed control. The soil test will provide you with specific recommendations for your plants.
The SoilKit will provide both pH and nutrient analysis for turfgrass and plants.
Mulching is one of the most effective ways to suppress weed pressure after you have planted your crop or landscape. Organic mulches such as pine bark and pine straw are very effective and have other added benefits such as improving soil characteristics, increasing plant growth, and the potential to increase your soil moisture. Inorganic mulches such as rocks and pebbles can also be very effective. While inorganic mulch is effective, they are more costly and do not add any other benefits to your soil. While ground cloth/ landscape fabric is very popular and challenging to install, it can be used for more than one season. Be sure not to use landscape fabric around plants since it can interfere with water and air movement into the soil. Mulch depths of 2 to 3 inches are important for the most effective weed control.
Organic mulches have several purposes in the landscape – weed control, conserving moisture, and aesthetics.
Cultivation is another method of weed control. Tilling and hand pulling weeds is very effective and allows you to see what weeds you are dealing with. Tilling also enhances soil structure and allows for easier uptake of water and oxygen in your soil. This method is more labor and time intensive but can more cost effective.
Chemical Control such as the use of a preemergence herbicide or spray herbicide can be very effective. It is important to have a proper ID of your weeds before application because there a specific product for specific weeds. Understanding what weeds, you are dealing with and how to read an herbicide label will ensure for a high success rate for chemical control.
The weed control methods discussed above can be very effective if done properly. It is important to understand what practices will work best for you as this will save time and money. If you have any questions regarding weed control in your landscape or garden, please reach out to your local UF/IFAS Extension Office for more information.
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.
If you’ve ever walked barefoot through a patch of burweed, you know this is a very unpleasant experience. Lawn burweed, also called spurweed or stickerweed, is a low growing winter annual that produces hard, spiny burs that contains the plant’s seeds. These burs or stickers make walking on grass extremely painful for not only people walking barefoot, but pets as well.
Lawn Burweed. Photo: Danielle Williams.
Dealing with lawn burweed can be tricky. Because lawn burweed is a winter weed, seeds actually germinate when temperatures are cool in the fall (late October-November). It then remains unseen during the cold months but as temperatures warm up in the spring, lawn burweed initiates a period of rapid growth and forms the spiny burs which may be hard to see but are easily felt. At this stage, the plant has set seed for next year and killing the remaining foliage won’t remove the burs. Moving forward, there are some things to consider.
Cultural Control
Burweed tends to be prominent in high traffic areas or areas where grass is declining so it is important to prevent infestations by maintaining a healthy, dense lawn. This can be achieved by fertilizing and liming according to soil test results as well as mowing at the proper height and frequency for your specific turfgrass. A healthy lawn can outcompete burweed for light, water, and nutrients and reduce the level of burweed infestation. For more information on maintaining your lawn visit: https://hort.ifas.ufl.edu/yourfloridalawn/
If burweed is only in isolated areas, you can always dig it up and dispose of it. Be sure to wear gloves and watch out for the stickers!
Chemical Control
Post-emergent control: Post-emergent herbicides are most effectively applied when burweed plants are young, actively growing, and haven’t set burs yet from December – February. Controlling burweed now is not impossible, but the burs have likely already formed and will remain present even after the weed dies. Additionally, since burweed is a winter annual, it will begin to die as temperatures reach 90 ◦F and above.
Look for herbicides containing the following active ingredients to help with post-emergent control:
Atrazine – sold under many brand names and safe in centipede, St. Augustine, and bermudagrass. Do not use in zoysiagrass or bahiagrass lawns.
Dicamba, mecoprop, 2,4-D – commonly sold in three-way formulations through many brand names. Generally safe in centipede, St. Augustine, bermuda, zoysia, and bahiagrass lawns.
Metsulfuron – sold under several brand names and safe in centipede, St. Augustine, zoysia, and bermudagrass. Do not use in bahiagrass. Be careful if used around ornamentals.
Thiencarbazone, iodosulfuron, dicamba. Safe in centipedegrass, zoysiagrass, bermudagrass, and St. Augustinegrass. Do not use in bahiagrass.
Pre-emergent control:If you are struggling with a lawn burweed infestation this spring, plan to do a pre-emergent herbicide application this fall. A herbicide containing the active ingredient, isoxaben can be used to control lawn burweed in centipedegrass, St. Augustinegrass, bermudagrass and zoysiagrass. In order for a pre-emergent herbicide application to be effective, it must be applied before the plant sprouts. For burweed, isoxaben can be applied in October or once temperatures fall to 55-60 ◦F and winter weeds begin to germinate.
Of course, before using any type of herbicide, always read the label instructions! If you have questions about lawn burweed control, please contact your local Extension Agent.
Spring is approaching and the main thing on my mind is controlling annual weeds. The most effective way to control crabgrass and other summer annual weeds is with a pre-emergent herbicide. Pre-emergent herbicides should be applied prior to weed seed germination. They don’t prevent germination, but they do prevent emergence of shoots and roots by forming a barrier on the soil surface.
Crabgrass growing in centipedegrass lawn. Photo credit: UF/IFAS Extension
Summer annuals such as crabgrass and chamberbitter begin to germinate when soil temperatures warm in the spring. Preemergence herbicides should be applied when daytime temperatures reach 65oF to 70oF for 4 or 5 consecutive days to form a barrier to help prevent these weeds from emerging. This is about the same time azaleas and dogwoods begin to bloom. Goosegrass is the exception for this temperature rule. For good goosegrass control, preemergence herbicides should be applied 3 to 4 weeks after the suggested daytime temperature application date.
It is important to note that you should only use preemergence herbicides on lawns that have been established for at least a year. These herbicides are prone to injure newly planted lawns. In addition, many preemergence herbicides may interfere with lawn grass seed germination, so make sure to refrain from reseeding for at least six after application.
Commonly available preemergence herbicides contain the active ingredients oryzalin, benefin, pendimethalin, DCPA and bensulide. However, there are a wide variety of products on the market. For more information on weed management please read the UF/IFAS publication “Weed Management Guide for Florida Lawns”.
Weeds can be the bane of the gardener’s existence and Extension Agents get a lot of questions on how to manage them throughout the year. Whether you are growing edibles, ornamentals, or turfgrass you have probably encountered a plant out of place which is basically the general definition of a weed. Just like with any other landscape challenge the first thing you need to do when dealing with weeds is accurate identification. Understanding the life cycle of the pest (weed in this case) you are targeting will be key for the most effective control with minimal inputs. Your local Extension office can assist with weed identification, and you can find a list by county here.
If you missed the live broadcast, you can watch the video on YouTube
Below are the links that were shared during the episode in the order discussed if you would like to follow along:
We have one more episode of Gardening in the Panhandle LIVE! scheduled this year on October 12th. We hope you will join us for Herbs and Cool Season Edibles!
Weed control is never ending in Florida landscapes. If there is a bare area of soil, weeds take advantage of that void and make themselves at home. Ideally, we would use good cultural practices that minimize weed invasion, but if prevention is ineffective and you need to use an herbicide, make sure you are using that tool properly.
When I talk to homeowners and commercial applicators about weed control, many times they have selected the appropriate product but are still struggling with management. While troubleshooting the problem, many times I discover, the reason is related to poor uptake because the client is not making herbicide applications to what I like to call “happy weeds.”
When using an herbicide, you need to think about how it works. Not the deep level chemical reactions, but rather consider how the active ingredient is going to be delivered to whatever physiological function of the plant it is targeting.
Does the herbicide need to be absorbed by the leaves/stems/roots?
Once absorbed, does it need to travel through the vascular system of the plant (translocation)?
What effect will temperature, moisture, mowing/trimming have on product uptake?
All these factors are very important because if a plant is stressed, the primary response is survival. During excessively hot weather plants close off stomata, form waxier surfaces, and do everything they can to retain moisture – which also includes reduced absorption of herbicides. In cool weather, the plant may be dormant or have slowed growth that will reduce translocation.
Mowing and trimming reduces leaf surface area minimizing uptake. Overcoming injury also triggers the plant to go into water conservation mode which also limits product uptake.
So, what do I mean by “happy weeds”? For herbicides to be effective, they should be applied when growing conditions are ideal for your target plant. Optimum soil moisture, soil temperature, ambient temperature, and minimal stress lead to “happy weeds” that are primed to accept herbicides and translocate if needed. Plants in survival mode will have their defenses activated and this decreases herbicide efficacy.
Always read and follow entire label instructions of all pesticides.
Chamber bitter is a weed commonly found in Florida landscapes.
Photo by Beth Bolles, UF Extension Escambia County
