For many years, Round-Up herbicide was recognized as a non-selective herbicide that contained glyphosate and was used to take out all vegetation. Round-Up is now sold as multiple different products containing many different combinations of herbicides. The University of Tennessee team recently composed a document that provides details on Round-Up. All should pay close attention to active ingredients contained within each Round-Up herbicide now sold.
Details from Tennessee here:
Two separate documents have been released that are quite helpful for those needing specific information related to turf disease control and weed control. Chemical Control of Turfgrass Diseases 2024 was recently released by Univ. of Kentucky, Rutgers Univ., and the Univ. of Wisconsin-Madison. This is a cost-free document which you can access by clicking on the above link.
In addition, a new release for weed control was recently put out: Turfgrass Weed Control for Professionals 2024 Edition. Purdue University leads the changes in this weed information and over the years contributions have been made by those at universities in Illinois, Indiana, Iowa, Kansas (K-State), Maryland, Michigan, Minnesota, Missouri, Nebraska, New Jersey, New York, North Dakota, Ohio, Pennsylvania, and Wisconsin. The link above will take you to access to this document which requires a low-cost purchase. You can also find this available at the check-in table at the K-State Turf and Landscape Conference in December, 2024.
Photo shows crabgrass emerging in Olathe, Kansas near a paved walking path in a park area. Greater soil warmth allows for earlier emergence in these areas. The photo was taken on April 21.
This blog post was presented last year, but we’re approaching that time of year again when crabgrass and other annual grassy weeds are approaching emergence.
As a reminder, if you want more detailed information on weed control in general, consider getting this 2022 publication that was developed by several state universities, including K-State, and was led by Purdue: “Weed Control for Turfgrass Professionals”
Preemergence herbicide applications for crabgrass, goosegrass, foxtail, and other annual grasses are underway. Here are bullet points to consider to increase the efficacy of the herbicide you use.
Maintain turf density and mow higher. Good turf density resulting from proper cultural practices for the grass you’re managing reduces encroachment of all weeds, including annual grasses. Mowing at the higher end of the recommended range has consistently shown significantly lower populations of crabgrass and other annual grasses than mowing at lower mowing heights.
Apply before emergence. Not all annual grass species emerge at the same time. For example, goosegrass emerges later than crabgrass. However, even within a species, emergence of new seedlings occurs throughout spring and summer. With most preemergence herbicides, when seedlings have emerged, they will not effectively control those plants. However, the application will control emergence of grasses beyond that date. Dithiopyr (Dimension) does provide control of crabgrass that has emerged but has not begun to produce tillers.
Use effective strategies to guide application. Calendar dates, soil temperature, flowering of ornamentals, and other strategies are all used to help guide applications and maximize herbicide residual during the period annual grasses emerge. Here are a few articles related to this subject:
How Preemergence Herbicides Work and Why They Fail (Univ. of Nebraska)
https://blogs.k-state.edu/turf/methods-of-predicting-crabgrass-emergence/
https://blogs.k-state.edu/turf/flowering-ornamentals-and-crabgrass-emergence/
Apply uniformly. Uniform application is critical – just like distributing paint evenly over your house is aesthetically pleasing. If you leave a section of the house unpainted, it’s clearly visible. Good annual grass control requires uniform application; if an area is not treated, it’s likely you’ll seed weed emergence there. Uniform application is achieved by proper spreader or sprayer calibration, colorants that indicate areas that have been treated with liquid products, and applying the product in two directions (half rate in each).
Split applications. Some, not all, preemergence herbicides generally provide better suppression of annual grasses when applications are split (1/2 rate each application), usually 6 to 8 weeks apart. This allows a higher level of herbicide presence on the soil surface, which will minimize weed emergence. Here’s an article from Purdue on this subject:
https://turf.purdue.edu/wp-content/uploads/2012/06/15_AGRY_Patton_sequential20apps.pdf
Water in after application. For preemergence herbicides to be activated and ensure uniform distribution on the soil surface, irrigation (or rainfall) after application is needed.
Find more information on weed control by clicking on the tags on the blog (left column), such as “weed control,” “crabgrass,” etc., or search by category on the right side of the page.
***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***
Don’t forget to follow the K-State Turf and Landscape Team on Twitter @KSUTURF
Also, visit our facebook page www.facebook.com/KSUTurf
The option for spring seeding is approaching. Cool-season grasses may have been seeded in the winter months, or can be seeded in spring – preferably in March and April in Kansas. Cool-season seed germination typically starts when the soil temperature reaches 50 F. Of course, fall seeding is preferred, but we are often dealing with situations where turf quality needs to be improved with spring seeding. One of the difficult problems is dealing with the emergence of summer annual weeds as the desired turfgrass species you’ve seeded begins to emerge. Here are herbicides that can be applied at the time of seeding to suppress summer annuals:
Tupersan (active ingredient siduron)
Siduron is a preemergence herbicide that can be used on cool-season grasses. It does provide weed suppression, but don’t expect the same level of weed control that we get with products that are commonly used on fully established turf. It is approved for used on colonial bentgrass, creeping bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescue. To view a Tupersan label, CLICK HERE
Tenacity (active ingredient meotrione)
Mesotrione inhibits photosynthesis in weeds once absorbed by shoots or roots. It originated based upon biochemicals observed in the plant called bottlebrush (Callistemon citrinus). It suppresses weeds as they absorb the herbicide at time of emergence and can also be used as a postemergence product. Midwest grasses for which it is labeled include buffalograss, Chewings fescue, creeping red fescue, hard fescue, Kentucky bluegrass, perennial ryegrass, and tall fescue. To view a Tenacity label, CLICK HERE
A number of other herbicides can be used once turfgrass reaches a point of maturity after seeding. Find more details about postemergence herbicides that can be used after seeding, and all information about turf weed by getting a copy of the 2022 edition of Turfgrass Weed Control for Professionals
Find more information on weed control by clicking on the tags on the blog (left column), such as “weed control,” “crabgrass,” etc., or search by category on the right side of the page.
***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***
This new blog video gives an update on a research project, a turf-related issue, or current concerns in the turf industry. Each one will be approximately 2 minutes long – you’ll see one periodically!
On this video, the first one, see the impact of nitrogen fertilization on crabgrass encroachment in a field project at the Olathe Horticulture Center. This study is being done at several universities in the north central U.S. including Iowa State, Michigan State, Minnesota, Missouri, Nebraska, North Dakota State, Ohio State, and Wisconsin. Most are looking at weeds in cool-season grasses, but you’ll hear about bermudagrass here.
It’s springtime and sedges are beginning to show up. Sedges are different than broadleaf and grassy weeds, and require different control strategies. Yellow nutsedge is the common sedge problem in our area. Treating yellow nutsedge when it’s young and just starting to appear is a good strategy that will result in better control.
Yellow nutsedge spreads primarily through its production of tubers and rhizomes – all can contribute to its expansion within a lawn.
Great resources to learn more about sedge control:
By Dr. Jack Fry
This blog post was presented last year, but we’re approaching that time of year again when crabgrass and other annual grassy weeds are approaching emergence.
As a reminder, if you want more detailed information on weed control in general, consider getting this publication that was developed by several state universities, including K-State, and was led by Purdue: “Weed Control for Turfgrass Professionals”
Preemergence herbicide applications for crabgrass, goosegrass, foxtail, and other annual grasses are underway. Here are some bullet points to consider to increase the efficacy of the herbicide you use.
Maintain turf density and mow higher. Good turf density resulting from proper cultural practices for the grass you’re managing reduces encroachment of all weeds, including annual grasses. Mowing at the higher end of the recommended range has consistently shown significantly lower populations of crabgrass and other annual grasses than mowing at lower mowing heights.
Apply before emergence. Not all annual grass species emerge at the same time. For example, goosegrass emerges later than crabgrass. However, even within a species, emergence of new seedlings occurs throughout spring and summer. With most preemergence herbicides, when seedlings have emerged, they will not effectively control those plants. However, the application will control emergence of grasses beyond that date. Dithiopyr (Dimension) does provide control of crabgrass that has emerged but has not begun to produce tillers.
Use effective strategies to guide application. Calendar dates, soil temperature, flowering of ornamentals, and other strategies are all used to help guide applications and maximize herbicide residual during the period annual grasses emerge. Here are a couple of articles related to this subject:
https://blogs.k-state.edu/turf/methods-of-predicting-crabgrass-emergence/
https://blogs.k-state.edu/turf/flowering-ornamentals-and-crabgrass-emergence/
Apply uniformly. Uniform application is critical – just like distributing paint evenly over your house is aesthetically pleasing. If you leave a section of the house unpainted, it’s clearly visible. Good annual grass control requires uniform application; if an area is not treated, it’s likely you’ll seed weed emergence there. Uniform application is achieved by proper spreader or sprayer calibration, colorants that indicate areas that have been treated with liquid products, and applying the product in two directions (half rate in each).
Split applications. Preemergence herbicides generally provide better suppression of annual grasses when applications are split (1/2 rate each application), usually 6 to 8 weeks apart. This allows a higher level of herbicide presence on the soil surface, which will minimize weed emergence. Here’s an article from Purdue on this subject:
https://turf.purdue.edu/wp-content/uploads/2012/06/15_AGRY_Patton_sequential20apps.pdf
Water in after application. For preemergence herbicides to be activated and ensure uniform distribution on the soil surface, irrigation (or rainfall) after application is needed.
Find more information on weed control by clicking on the tags on the blog (left column), such as “weed control,” “crabgrass,” etc., or search by category on the right side of the page.
***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***
Don’t forget to follow the K-State Turf and Landscape Team on Twitter @KSUTurf
Also, visit our facebook page www.facebook.com/KSUTurf
Here are video recordings of field day presentations (last August) of a few speakers you’ll hear at the Kansas Turf and Landscape Conference, which is in Manhattan, KS on December 1 and 2. You can’t get pesticide recertification credit by watching the videos below, but you can if you come to the conference (7 cr. of 3A and 3B will be available!).
Field Day recordings – Click on the name to see it!
Dr. Raymond Cloyd – Insect Update
Dr. Megan Kennelly – Disease Update
Sessions at the upcoming conference include Basic Turf; Nursery & Landscape; Diseases, Insects & Weeds; Advanced Turf; and Sustainability, Technology & Water Management. You can download the conference brochure and get exhibitor information by CLICKING HERE!
Complete online registration by CLICKING HERE!
Cool-season broadleaf weeds, including winter annuals and perennials, wait until temperatures cool down and then emerge during autumn. The photo above was taken in Olathe in late October. Targeting broadleaf weeds during autumn, when temperatures are suitable for application, results in good broadleaf weed control. Immature weed seedlings are more susceptible to herbicides than mature weeds. Find more information regarding weed control in this valuable resource. The updated “Turfgrass Weed Control Guide for Professionals – 2021” provides weed identification and control information that turfgrass professionals can use to develop effective weed control programs for golf courses, athletic fields, sod farms, lawns, and other turfgrass systems. The recommendations apply to the majority of the United States, with input from experts in Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New Jersey, New York, Ohio, Pennsylvania, and Wisconsin.
CLICK HERE to purchase the Turfgrass Weed Control Guide for Professionals – 2021
This guide will also be available for sale at the Kansas Turf and Landscape Conference on December 1 and 2, 2021 in Manhattan, KS. You can download the conference brochure and get exhibitor information by CLICKING HERE! Complete online registration by CLICKING HERE!
This form is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
