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!
by Mark Tancig | Feb 11, 2021
Gardeners worldwide and throughout time have bemoaned weeds. In Florida, we get to enjoy weeds all year long! Our February Gardening in the Panhandle (GIP) Live episode focused on weeds and weed control. Many homeowners are interested in ways to control weeds and UF/IFAS Extension and your local extension agents are here to help. The following is a summary of the topics we discussed and links for more research-based information on weeds.
What is a Weed?
Many folks come to the extension office holding a plant and ask, “Is this a weed”? Well, whether it is a weed or not is up to the individual, as the only definition for a weed is “a plant out of place”. Bermudagrass and Oxalis are good examples of plants that some try to grow while others try to kill. One person’s weed is another’s wildflower! However, to be clear, plants classified as invasive by UF/IFAS and governmental entities are officially weeds. There are resources to help identify several common plants that are generally considered weeds by most homeowners and landscapers.
Weed ID Links
Common, and aggravating, weeds.
How to Prevent Weeds?
There are some general gardening practices that can help prevent weeds so there is less of a need to control them. A lawn that is healthy is less likely to be invaded by weeds and the use of mulch can greatly reduce weed growth in planting beds. Other practices, like the placement of weed fabrics/cloths are less effective and/or less practical in many garden situations.
Weed Prevention Links
How to Control Weeds?
Once you know and/or decide that what you have is a weed and that it needs to be dealt with, then you have to consider your control options. Prevention, as mentioned above, is key but sometimes you may need to use other methods of control, such as physical, mechanical, and/or chemical means. With chemical weed control, it is important to always read and follow the product label.
Weed Control Links
General dates of common annual weed emergence. Credit: Dr. Ramon Leon, UF/IFAS.
Specific Weed Recommendations
When managing pests, proper identification is key to effective control. Because some weeds are annuals, and present either during the cool or warm season, and others are perennials, proper weed identification can provide a more detailed control strategy. Use the weed ID links above and the document links below for more precise, and effective, weed management.
Species-Specific Control Links
If you need additional assistance with weed control, please contact your local county extension office. Please tune in for future GIP LIVE episodes for more research-based information on gardening topics.
by Carrie Stevenson | Dec 4, 2015
______________________Figure 1. Doveweed patch in St. Augustinegrass sod.__________________________
Ramon Leon, WFREC Weed Specialist
Doveweed (Murdannia nudiflora) is a summer annual weed species that belongs to the dayflower family. Over the last three years, this weed has become an important weed problem in residential lawns and sod production.
This weed has two key characteristics that make it successful. First, its seeds germinate late during the spring when soil temperatures reach 65-70°F. This represents a problem because at this time the effect of preemergence (PRE) herbicides applied in February or March might be too low to provide good doveweed control. Second, the leaves of this weed can be confused with St. Augustinegrass and centipedegrass leaves, and many people do not notice doveweed until the plants are large and are displacing the turf. Doveweed leaves are thick with a shiny rubbery texture. The plant produces creeping stems (stolons), and mowers can break these stolons spreading this weed across the field.
It is very important to keep in mind that doveweed prefers wet areas, so drainage issues or over-watering will favor the establishment and growth of this weed. For this reason, ensuring irrigation is not excessive is a key management practice to control this problem. Another cultural practice that plays a major role on doveweed management is mowing. Mowing too short and too frequently will favor doveweed because its leaves will grow horizontally avoiding the mower blades. Chose a mowing height that allows good ground cover , yet only removes a third of the turf leaf blades.
___________Figure 2. Individual doveweed plant showing flowers, fruits, and stolons with root in nodes.________
Control
Doveweed is easier to control before emergence than when plants are well established. Atrazine is one of the most effective herbicides to control doveweed. A maximum rate of 1 lb. of active ingredient (ai) per acre (A) and no more than 2 lb. ai per year are recommended to achieve both adequate control and avoid turfgrass injury. Atrazine should be applied right before or soon after doveweed emerges to maximize control.
For PRE control, S-metolachlor (Pennant Magnum™), dimethenamid-P (Tower™), and indaziflam (Specticle™) are herbicides that can considerably reduce doveweed establishment, especially if the application is done closer to doveweed emergence timing. These herbicides also provide good control of other important weed species such as crabgrass and goosegrass, which emerge earlier in the spring. In order to control early emerging weeds and doveweed, split applications are preferred. For example, the first application is done at the end of February or early March and the second one 4 to 6 weeks after. In this way, we can extend PRE control until doveweed starts emerging.
If we observe doveweed emerging after PRE applications, we have several postemergence (POST) herbicides that will provide control, as long as the plants are less than 2 inches in size and have not produced stolons. Products containing 2,4-D and dicamba can provide fair control of doveweed. However, repeated applications or applications in combination with other herbicides will be required for adequate control. There are commercial products with formulations that combine 2,4-D or dicamba with other herbicides such as mecoprop-p, carfentrazone (Quicksilver™), thiencarbazone and iodosulfuron (e.g., Celsius™, Tribute Total™). This type of three− or four−way combination can provide enhanced doveweed control. If doveweed has fully displaced the turf in spots, it is probably easier and more effective to kill doveweed with a directed application of glyphosate (RoundUp™) and re-seed or re-sod the area.
Because doveweed seeds can live for several years in the soil, it will take two to three years of continuoous control to eliminate doveweed populations. Although herbicides are useful tools to control doveweed, the most important factor to prevent doveweed problems is to have vigorous healthy turf. Doveweed requires a lot of sunlight, so if the turf effectively shades the ground, doveweed will have a hard time growing and producing new seed.
For more information on managing turf weeds download:
