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”.
Syrphid larva and oleander aphids. Photo credit: Lyle Buss, University of Florida.
When we think of pests we tend to focus mainly on insects. Insects make up roughly 80% of animal life, however only about one percent of insects are considered pests. The rest help pollinate crops, kill pests, clean up dead stuff, and make honey. Unfortunately, plants suffer from many more types of pests such as weeds, disease, and us. This episode of “Gardening in the Panhandle LIVE!” was all about managing pests.
Many soft-bodied insect pests can be controlled with insecticidal soap. Many insecticidal soaps are on the market that can help control pests like aphids and whiteflies. However, dish soaps are manufactured for cleaning dishes and not labeled for pest control. More information on insecticidal soaps can be found in the publication “Managing Plant Pests with Soaps”.
Although dish soap isn’t a good option for insect control, there are some things from around the house that can be used to help manage pests. The publication “Do-It-Yourself Insect Pest Traps” offers some excellent options for monitoring and managing pests with traps.
Florida is home to a plethora of insect pests. The Ask IFAS website has many articles on insect pests common in the garden.
Companion planting is the practice of planting two or more plant species close to each other to improve growth and/or pest control of one or more of the species. The article “Companion Planting: What is it?” offers some great recommendations and examples of this technique. Marigolds are an excellent companion plant because they can help deter and suppress nematode populations.
Some people prefer to only use naturally derived products for pest control. The publication “Natural Products for Landscape and Garden Pests in Florida” extensively reviews some of these products. Bacillus thuringiensis (BT) is a bacteria found in soil that can be used for caterpillar pest control.
We love our squash, cucumbers, and watermelons in the South, however there are a number of insects that like to eat them too. More information on cucurbit insect pests and their management can be found in the publication “Insect Management for Cucurbits”.
Armyworms like to feed on just about everything. The Ask IFAS website has a nice collection of publications on all types of armyworms.
Some fungi are fun to eat while others kill our landscape plants. One common fungal disease found in the landscape is Entomosporium leaf spot. This disease is very common on Indian hawthorns. The article “Keep an Eye on Your Indian Hawthorn” describes this disease and it’s control.
Aphids are a very common insect pest. In fact, some plant species have specific aphids. More information on different aphid species and their control can be found in the publication “Aphids on Landscape Plants”.
A plant in the wrong place is considered a weed. Some plants are particularly good at finding the wrong place and can take over our lawns. The publication “Weed Management Guide for Florida Lawns” offers solutions on controlling common lawn weeds.
Cockroaches do a nice job cleaning up litter when they’re outside, but we don’t need want them in our houses whether they’re cleaning up trash or not. The publication “Cockroaches and Their Management” is a great resource for cockroach species identification and management.
As previously mentioned, there are a lot more good insects than bad insects. For more information on predatory insects and biological controls check out the publication “Natural Enemies and Biological Control”.
Nature is fascinating and most people are lifetime learners. To help find out what you’re looking at, give the iNaturalist website and app a try.
Armadillos don’t mean any harm and can be kind of cute. However, they can make a mess of our yard and they build their dens in some undesirable locations. The publication “The Nine-Banded Armadillo” provides information on armadillos and their management.
Fire ants are pests of our lawns and pastures and their sting is brutal. For more information on fire ants please refer to the publication “Managing Imported Fire Ants in Urban Areas”.
Pests can be pesky, but they are manageable if you keep up with the art and science of their control. If you need help with identification and pest management options please don’t hesitate to contact your local Extension Office.
Past episodes of Gardening in the Panhandle LIVE can be found on our YouTube playlist.
It’s the most asked question of Extension agents everywhere. “What is this weed and what herbicide should I buy to kill it?” The first part of that question is straightforward. Between personal field experience, formal plant identification training, and a team of weed science specialists to call on, Florida Extension Agents can get your weed accurately identified. The second part of the question is slightly more nuanced. Many weed problems can be avoided by following lawn and landscape Integrated Pest Management (IPM) practices, like not overwatering, mowing at the correct height, using mulch where you can, etc., but sometimes herbicides are required. For these situations, if you follow the “homeowners only need four post-emergent herbicides rule”, you’ll be ready for any weed challenge you face!*
Doveweed seedlings just emerged on July 9, 2021. Photo courtesy of Daniel Leonard.
The first weed scenario you should be prepared for is spot spraying weeds in landscape beds and around hardscapes like concrete pads, sidewalks, pools, driveways, etc. For this situation, you’ll turn to the backbone of the four herbicides rule and a staple in any weed management program, glyphosate. Glyphosate is the active ingredient (AI) in many non-selective products ranging from the infamous Roundup brand to cheaper generics like Killzall and Cornerstone. Glyphostate is extremely cost-efficient and very effective on a huge range of emerged weeds including grassy weeds, broadleaf weeds, and even sedges (also called nutsedge or “nutgrass”). Just be sure not to get any overspray on desirable plants or they’ll be seriously damaged!
The second situation we face occurs when “bad” grassy weeds invade landscape beds, shrubs, and vegetable gardens. These cases call for a grass-selective herbicide that you can spray right over the top of your broadleaf annuals, perennials, and shrubs to take out the unwanted grasses. In this case, there are two options at your disposal: sethoxydim (AI in many products like Fertilome Over the Top, Hi-Yield Grass Killer, Poast, etc.) and fluazifop (AI in the product Fusilade). Both products work well in removing weeds like crabgrass, bermudagrass, goosegrass, and others and can be safely applied over the top of many ornamentals.
Seeds from annuals like Chamberbitter easily get into mulch and turfgrass from surrounding areas. Photo by Beth Bolles, UF Extension Escambia County
From time to time, we need to treat a broadleaf weed like dollarweed, doveweed, chamberbitter, or any number of others, that have invaded our lawn grass. Some of these weeds are tougher than others, but almost all of them can be managed with the proper rates of 2,4-D, Dicamba, other similar products, or a combination of several of them. These active ingredients have been on the market for decades so there are many generic options at your disposal. However, if you have a truly tough broadleaf weed problem, the newer product Celsius WG from Bayer (a combo of Dicamba and two newer AIs), while a little pricey and only available online or at specialty chemical dealers, is well worth the expense and knocks out the most gnarly of lawn weeds.
Finally, there is a category of weeds that aren’t broadleaves and aren’t quite grasses either. These are the sedges. Commonly known around the Panhandle as “nutgrass”, sedges are a serious pest of lawns, particularly those that stay a little on the damp side, and vegetable gardens. Sedges, with their glossy leaves and distinctive flowers, stand out in lawns and gardens, are very unsightly in an otherwise well-maintained area, and can outcompete the desirable plants they invade. Fortunately, there are several AIs that work very well on sedges and are safe to use around turfgrass and many other plants. The most effective sedge herbicide AI for homeowners is halosulfuron-methyl (AI in Sedgehammer in lawns and Sandea and Profine in vegetables). Sedgehammer works very slowly (results can take up to a month) but is very safe in turfgrass and ornamentals and highly effective! If Sedgehammer and other halosulfuron products are difficult to obtain, Imazaquin is a slightly less effective but more common substitute. This AI can be found in the product Image Kills Nutsedge and is safe for use in turfgrass and most ornamental plantings.
The challenge of controlling the many types of weeds in your lawn, landscape, and vegetable garden seems daunting, but having just four basic classes of herbicides on hand can greatly simplify things! Whether you need to control a broadleaf, grass, or sedge weed problem, putting together a weed control toolbox containing a non-selective herbicide like glyphosate, a broadleaf selective like 2-4,D, a grass selective like sethoxydim, and a sedge selective like halosulfuron-methyl can allow you to handle most any weed you come across at home. For more information on controlling weeds in home landscapes and gardens or any other horticultural topic, contact your local UF/IFAS Extension office. Happy gardening!
*Most homeowners discover weed problems after the weeds are already up and growing, making post-emergent products necessary. Pre-emergent products have a place in weed management programs but are not the focus of this article.
Turf lawns provide an excellent groundcover that hold soil in place, filter pollutants, and are beautiful. However, turfgrass may not be your first groundcover choice, due to heavy shade, landscape layout, or just personal preference. In that case, there are a lot of alternative groundcovers on the market. To help determine what groundcovers do best under certain conditions and to provide information on lawncare and groundcover maintenance, this month’s Gardening in the Panhandle LIVE! was all about groundcovers.
‘Needlepoint’ Perennial Peanut in a yard. Photo Credit: Daniel Leonard, University of Florida/IFAS Extension – Calhoun County
Turfgrass/Groundcover Selection
The University of Florida/IFAS has a long list of publications on alternatives to turfgrass. The comprehensive list can be found at Ask IFAS: Groundcovers.
Groundcover options for the shade include Algerian ivy, Asiatic jasmine, and mondo grass. Read more about these and other shade friendly species at “Gardening Solutions: Groundcovers for the Shade”.
Frogfruit can tolerate full sun and partial shade.
White clover is a groundcover that may be best suited in a mix with other groundcover species. The publication “White Clover” provides some excellent information on growing this plant.
A number of factors come into play when you are choosing a turfgrass species. Some species are more tolerant of shade than others and maintenance levels are species and variety specific. The “Choosing Grass for Your Lawn” webpages can help answer some common questions. For additional information on turfgrass species a list of EDIS publications and other UF/IFAS websites is available at Ask IFAS: Your Florida Lawn. (Note: Buffalograss is not recommended for Florida.)
A soil sample is a good place to start to determine the root of the issues you may have in your lawn. Follow these simple steps to collect and submit a sample for accurate analysis.
Weed management can be difficult in turf and other groundcovers. Cultural, mechanical, and chemical controls can help keep weeds under control. The “Weed Management Guide for Florida Lawns” provides control options for the majority of weeds you’ll encounter in your lawn. More information on weed control in turf alternatives can be found in the publication “Improving Weed Control in Landscape Beds”.
Virginia buttonweed is a common weed that is often difficult to control. Doveweed can also be difficult to control.
The publication “Adopting a Florida Friendly Landscape” outlines the nine principals to help you design, install, and maintain a landscape that will thrive in our climate.
Fertilizer is required to maintain a healthy lawn. A list of lawn fertilization publications and links can be found at Ask IFAS: Lawn Fertilizer.
Lawns in the southeast are susceptible to a number of different diseases mostly thanks to our hot and humid weather. But there are some preventative and curative practices you can implement to help keep disease under control. The “Turfgrass Disease Management” publication answers a lot of questions about disease control.
Past episodes of Gardening in the Panhandle LIVE can be found on our YouTube playlist.
