by Daniel J. Leonard | Aug 26, 2021
Nearly everyone likes turfgrass lawns. They’re pretty and green. They filter water, chemicals, and nutrients before they enter our groundwater systems. They provide a recreation spot for people and pets. But lawns also come with maintenance tasks, one of which is weed control. Fortunately, keeping our common Centipedegrass lawns relatively weed free is as simple as smart management and utilizing herbicides effectively. Though the number of herbicides available for purchase can be overwhelming, you only need three to keep weeds at bay – a selective grass herbicide, a strong broadleaf herbicide, and a sedge herbicide!
Dollarweed, one of the toughest broadleaf weeds for homeowners to control. Picture courtesy of Julie McConnell, UF/IFAS.
First up on the essential herbicide list is the selective grass herbicide Sethoxydim. While most folks’ weed focus is centered on broadleaf weeds, grassy weeds like Crabgrass, Bahiagrass, Goosegrass, and others can be just as problematic and make for a very unsightly lawn. Enter Sethoxydim. Cheap and easy to find, Sethoxydim is offered as the active ingredient in many branded products like Fertilome Over the Top Grass Killer, Hi-Yield Grass Killer, and many more. These products control weedy grass species without seriously harming Centipedegrass or broadleaf ornamental trees and shrubs (Centipedegrass may temporarily be yellowed after sethoxydim application but will recover). Not only will it kill out the unwanted grass growing in your Centipede, but it will also remove these weeds from your flower beds!
Second, having a strong broadleaf herbicide on hand is necessary. I say “strong” because many of the homeowner grade products available at garden centers simply don’t have the “juice” to control tough broadleaf weeds like Dollarweed, Doveweed, Virginia Buttonweed, and others. For this job, I prefer to use a commercial grade 3-way product like Celsius WG by Bayer. Celsius WG is a 3-way combination herbicide with a healthy dose of Dicamba as its primary ingredient. Though Dicamba is a notoriously volatile chemical known to cause damage to unintended plants through drift in hot weather, combining it with the two other products in Celsius WG makes it safe to use in lawns, even in the heat of summer. While strong broadleaf herbicides like Celsius WG are expensive on the front end, don’t let that deter you. These products wind up being very cost effective in the long run due to minute mixing rates (one bottle goes a very long way in most residential lawns) and effectiveness – you simply will not need to waste time and money spraying lawn weeds over and over to obtain control like is necessary with lesser products – one or two applications will solve the toughest broadleaf weed problems.
Finally, any good lawn weed control program will include a quality sedge control herbicide. Sedges (often called “nutgrass”) look like grasses but are a completely different category of plants and as such, require specialized herbicide chemistries to achieve control. Sedge weeds prefer wetter areas of lawns, though they can occur in pretty much any lawn site and are very unsightly. For this weed category, there are several options available to homeowners. The one that consistently provides the best control in lawns is Halosulfuron-methyl, the active ingredient in the aptly named product Sedgehammer. Conveniently coming in individually pre-mixed packets for small lawns or a larger bottle when more acreage is to be treated, Sedgehammer couldn’t be easier to mix and use. While Sedgehammer and similar products are extremely effective in controlling various sedge weeds, they tend to work very slowly, and patience is required. Weeds immediately stop growing following a Sedgehammer application, but it can take up to three weeks to notice the sedges dying.
While having and using the above three herbicides can control almost any weed homeowners may encounter in their lawns, it is important to remember that herbicides are not substitutes for proper lawn management. When good cultural practices in lawns are followed, such as mowing at the correct height, only watering when necessary, following UF/IFAS fertilizer recommendations, etc., chemical weed control may not even be necessary in many cases! Also, once the decision to purchase and use chemical herbicides has been made, it is critical that one always read the label before using any herbicide product. This ensures safe and effective use of the product; the label is literally the law!
For assistance in choosing the correct herbicide for your lawn and other lawn care concerns, contact your local UF/IFAS Extension Office! Happy Gardening!
by Daniel J. Leonard | Aug 18, 2021
One of the most conspicuous outcomes from Hurricane Michael was the complete disruption of local lawns and landscapes. Giant holes where tree roots once existed, ruts and compacted ground from clean-up equipment, and formerly shaded acres flooded with fresh sunshine were three very common situations property owners suddenly found themselves faced with. An unforeseen consequence of all this newly bare ground ripe was the intrusion by a variety of very aggressive weeds. One invasive exotic weed that has made itself right at home in many county landscapes following Michael and that I’ve seen lots of lately is Torpedograss (Panicum repens).
Often brought into landscapes with “fill-dirt” and “topsoil” applications or spread through mowing, Torpedograss is an aggressive perennial grass in the same plant family as Bermudagrass and Cogongrass. Like many invasive exotic species, Torpedograss was introduced into the United States in the late 1800’s from its native Africa and Asia as a potential forage crop. Unlike its cousin Cogongrass, the Torpedograss is highly palatable to cattle and so gained a quick following among the ranching community. Unfortunately, over the next century, Torpedograss had left the pasture and turned into one of the biggest pest plants in Florida, ruining many a lawn, taking over 70% of the state’s public waterways, disrupting native marshlands, and costing Florida over $2 million a year to control!
Torpedograss growing in a Calhoun County gravel driveway. Photo courtesy of Daniel Leonard.
Torpedograss spreads rapidly through underground, sharply pointed, white-colored, “torpedo-like” growing tips and can dominate wet or dry areas in short order. The species often hides in lawns when mixed in and mowed with other turfgrasses (especially Zoysiagrass, which it closely resembles), growing unnoticed until infestations are severe and control options are few. This makes scouting for the weed and accurate identification crucial! Torpedograss can be identified by its bluish-green leaf and stem color, hairy leaf edges, stiff overall appearance, distinctive panicle-type flowers, and can grow quickly to 3’ or so in height, spreading indefinitely. Though it initially can resemble other turf species, once you know what you’re looking for, Torpedograss stands out visually amongst its competitors.
After identifying Torpedograss, control methods can be chosen depending on the site it has infested. In lawns, options vary based on turf species. If infestation occurs in the common Centipedegrass and Bahiagrass lawns of the Panhandle, options are few. Products with the active ingredient Sethoxydim (Poast, Fertilome Over the Top, Southern Ag Grass Killer, etc.) can suppress Torpedograss growth in these situations but will not destroy it and are not permanent options. If the area infested is not large, killing the whole spot out with a non-selective herbicide like Glyphosate (Roundup and generics) and then resodding is probably a better option. In Bermudagrass or Zoysiagrass lawns, products with the active ingredient quinclorac (Drive and generics) are very effective at controlling Torpedograss without having to go the “nuclear” glyphosate route. Unfortunately, there are no effective controls for Torpedograss in St. Augustinegrass lawns.
In landscaped beds, Torpedograss is somewhat easier to control. Hand pulling in beds can be effective where new invasions occur but are impractical once the weeds gain a strong foothold. Once that occurs, chemical control is required. In bare or mulched areas away from plants, careful spot spraying in bare areas with a 2-3% glyphosate solution is extremely effective. Where the Torpedograss has grown into and through landscape plants, an “over-the-top” application of fluazifop (Fusilade) will take out the weed without harming most ornamental plant species! (Be sure to check the Fusilade label to make sure your ornamental plant species are safe to apply to!)
Torpedograss is one of the most serious, yet overlooked, invasive plants that occurs in Florida. However, through prevention and control techniques like cleaning mowers when mowing infested areas, accurate identification, and prompt, effective herbicide use, you can keep the weed from taking over your lawn and landscape! For assistance in identifying and controlling Torpedograss and other lawn weeds, contact your local UF/IFAS County Extension office! Happy gardening!
by Danielle S. Williams | Aug 11, 2021
Integrated Pest Management or ‘IPM’ is a sustainable approach to managing plant pests by using several different methods to cause the least harm to people, property, and the environment. IPM focuses on the management of problems rather than their eradication. Using IPM strategies in your garden is one way to ensure its productivity!
Avoiding Pest Problems
Prevention is key to IPM! It is important to select the right plant, for the right place at the right time. It’s also important to select pest-resistant plant varieties and maintain healthy plants through proper watering and fertilization.
- Plan before you plant. Be sure not to plant in a location not suited for a particular plant. Stressed plants are more susceptible to insects and disease.
- Start with healthy plants. Do not plant plants with insects or disease.
- Monitor the lawn and garden regularly. You’ll want to be able to detect a pest problem earlier rather than later.
- Water and fertilize properly. Too much of either can make plants vulnerable to insects and disease.
- Encourage beneficial insects in your garden. Learn to recognize the insects in your garden and let the good ones do the work for you!
Recognizing Pest Problems
Depending upon the insect and the life cycle stage they are in, they may look different than we are used to! Here is a photo of the pupal stage of a lady beetle.
Scouting or monitoring the garden or plants in the yard frequently helps detect problems early. Some of the common insects you’ll find in your garden are: aphids, mealybugs, scales, whiteflies, thrips, mites, caterpillars, and stinkbugs. Often times you’ll find damage from the insect before you see the insect itself. Chewed or deformed leaves, sooty mold or a colony of ants scurrying up and down stems are all signs an insect may be present.
Treating Pest Problems
IPM is the best strategy for dealing with pests in the lawn and garden. IPM strategies:
- Remove affected plant leaves or parts. If an insect or disease is heavily concentrated in an area, you can reduce or eliminate the problem by simply removing it.
- Pick insects off by hand. Be sure to dispose of them so they don’t make it back into the garden.
- Look for beneficial insects. If you see a pest outbreak, try to determine if it is being managed by natural enemies. Many insects such as ladybugs and lacewings prey on pest insects and removing them will just help the pest insects. If you need help identifying insects, contact your local county Extension agent!
- Try the above strategies before pesticide use. If the problem persists and pesticides are needed, use products that have a reduced-risk to the environment such as insecticidal soaps, horticultural oils, botanicals, or microbials.
- Read and follow all pesticide label instructions. The label is the law!
For more information on integrated pest management, please visit:
by Stephen Greer | Aug 11, 2021
One big goal of establishing a home lawn and landscape is to enjoy an attractive setting for family and friends, while also helping manage healthy soils and plants. Soil compaction at these sites can cause multiple problems for quality plants establishment and growth. Soil is an incredibly important resource creating the foundation for plants and water absorption.
Photo courtesy: Stephen Greer, UF IFAS
Soils are composed of many different things, including minerals. In Florida, these minerals often include sand of differing sizes and clay in the northern area of the counties in the panhandle of Florida. Soil is also composed of organic matter, nutrients, microorganisms and others. When soil compacts, the air spaces between the sand or clay are compressed, reducing the space between the mineral particles. This can occur anytime during the landscape and lawn construction phase or during long term maintenance of the area with equipment that could include tractors, mowers, and trucks.
What can be done to reduce soil compaction? There are steps that can be taken to help reduce this serious situation. Make a plan on how to best approach a given land area with the equipment needed to accomplish the landscape of your dreams. Where should heavy equipment travel and how much impact they will have to the soils, trees, and other plants already existing and others to be planted? At times heavy plywood may be needed to distribute the tire weight load over a larger area, reducing soil compaction by a tire directly on the soil. Once the big equipment use is complete, look at ways to reduce the areas that were compacted. Incorporating organic matter such as compost, pine bark, mulch, and others by tilling the soil and mixing it with the existing soil can help. Anytime the soil provides improved air space, root will better grow and penetrate larger areas of the soil and plants will be healthier.
Even light foot traffic over the same area over and over will slowly compact soils. Take a look at golf course at the end of cart paths or during a tournament with people walking over the same areas. The grass is damaged from the leaves at the surface to the roots below. Plugging these areas or possibly tilling and reestablishing these sites to reduce the compacted soils may be necessary.
Photo courtesy: Stephen Greer, UF IFAS
Water absorption is another area to plan for, as heavy rains do occur in Florida. Having landscapes and lawns that are properly managed allow increased water infiltration into the soil is critically important. Water runoff from the site is reduced or at least slowed to allow the nutrient from fertilizers used for the plant to have more time to be absorbed into the soil and taken up by the plants. This reduces the opportunity for nitrogen, phosphorus, and other nutrients to enter water areas such as ponds, creeks, lagoons, rivers and bays. Even if you are miles from an open water source, movement of water runoff can enter ditches and work their way to these open water areas, ultimately impacting drinking water, wildlife, and unwanted aquatic plant growth.
Plan ahead and talk with experts that can help with developing a plan. Contact your local Extension office for assistance!
by Daniel J. Leonard | Jul 22, 2021
If you’ve taken care of your yard properly from spring green-up to now (mid-July), you might think you can comfortably coast into the cool temperatures of fall without any problems. You would be mostly right, save for one extraordinarily tough weed that waits until the depths of summer to rear its troublesome head: Doveweed (Murdania nudiflora).
Doveweed seedlings just emerged on July 9, 2021. Photo courtesy of Daniel Leonard.
Doveweed is an insidious invader of Panhandle lawns. In the Panhandle, Doveweed germinates (sprouts) long after most other summer annual weeds, from late May-June when soil temperatures reach ~70°F. This allows it to sneakily avoid spring pre-emergent herbicide applications and even early summer post-emergent applications that target common weeds like Florida Pusley, Spurge species, and others. Doveweed also looks an awful lot like many of our common lawn turfgrasses, especially Centipede and St. Augustine Grass. It possesses thick, shiny, grass-like foliage and even grows in a spreading, low to the ground fashion. This mimicry causes many homeowners to not realize there is a problem until it’s too late. Once Doveweed is mature and displaying its characteristic purple flowers, it is very difficult to control. Finally, Doveweed is extremely tough and aggressive, particularly thriving in moist areas of the lawn. In these areas, Doveweed can easily outcompete the desirable turfgrass and, without intervention by you, will soon have the whole lawn to itself.
Controlling Doveweed is no easy task and requires a combination of practices to keep it out of your lawn. The first line of defense against any weed, Doveweed included, is through proper cultural practices. In turfgrass lawns, this means ensuring that you mow your lawn regularly and at the proper height (2.5” or so for Centipedegrass), keeping the lawn irrigated during droughty periods, fertilizing based on a soil test, etc. Being diligent in the above tasks will go a long way to ensuring that your turfgrass is healthy and better able to ward off a Doveweed invasion. However, even when homeowners maintain their turf perfectly, chemical herbicides are usually required to keep Doveweed at bay.
Doveweed patch in St. Augustine Sod.
While many commonly used homeowner herbicides are not effective on Doveweed, there are several quality options at your disposal.
- Doveweed is most easily controlled with preemergent herbicides, specifically one of the following: Atrazine, Pennant Magnum (S-metolachlor), Tower (dimethenamid), and Specticle (indaziflam). The issue with pre-emergents is that most folks shelve them after spring application in February or March. Since these products lose their efficacy after 4-6 weeks, Doveweed’s emergence in May is undeterred. To obtain control on Doveweed with these products, split the spring application and apply once in late Feb/early March and again in mid-late April.
- Doveweed can also be controlled by post-emergent herbicides after it is up and growing, though multiple applications may be required. The most effective formulations contain a combination of 2,4-D or Dicamba and other herbicides. While most of these products have at least fair efficacy on Doveweed, stronger, more expensive products like Celsius, Tribute Total and others provide better results.
- If Doveweed has already displaced turfgrass in large areas of your lawn, you may unfortunately be better off to make an application of a non-selective herbicide like glyphosate (Roundup), kill out the entire area of infestation and start over by resodding.
While Doveweed is a major problem in Panhandle lawns, it doesn’t have to be in yours! By keeping your turf healthy with proper cultural practices and making timely applications with effective herbicides, your lawn can be a Doveweed free zone! For assistance in Doveweed identification in your lawn, help choosing herbicides and calculating application rates, or any other horticultural information, contact us at the UF/IFAS Calhoun County Extension office! Happy Gardening!
