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K-State turfgrass specialist urges mid-summer checkup on lawns

Many Kansas landscapes include warm-season grasses, which require a little care in order to stay healthy during the hot summer months.

Hoyle says warm-season grasses may need fertilizer to remain healthy

MANHATTAN, Kan. – Kansas State University Associate Professor and Extension Turfgrass Specialist, Dr. Jared Hoyle says homeowners ought to be thinking about a mid-summer checkup on their lawns, which likely includes applying fertilizer and weed killer.

Many Kansas summer landscapes include warm-season grasses, namely bermudagrass, zoysiagrass and buffalograss. Each of those requires a little care in order to stay healthy through the hot weeks ahead.

“Those three grasses are not all created equal and some grow faster than others, which means we need to feed them a little bit different,” said Hoyle, an associate professor in the Department of Horticulture and Natural Resources.

For bermudagrass and zoysiagrass, Hoyle suggests applying a total of 1-3 pounds of nitrogen per 1000 square feet during a typical growing season, which is the beginning of May through the middle of August.

“You can split that up into multiple applications of a quick release fertilizer, or you could do fewer applications of a slower release,” he said. “But the main goal is 1-3 pounds of nitrogen per 1000 square feet regardless of what number or percentage product you’re using.”

Buffalograss does not require as much nitrogen. Studies at Kansas State University indicate that “about 1 pound of nitrogen per year for 1000 square feet is good,” according to Hoyle.

“It’s hard to split up a pound over multiple applications, so that’s one where you might want to look at a slow release to put that pound of nitrogen per 1000 square feet throughout the year,” he said. “You can do that right now and that will get you through the rest of the year with a slow release fertilizer.”

In addition to fertilizing warm-season grasses, Hoyle said homeowners should be looking at ways to control thatch and weeds in the lawn.

“We really like to preach that if you are going to do something with the lawn — whether it is fertilizing or watering — do it when it’s actively growing,” Hoyle said. “Right now, with warm-season grasses, if you have a thatch problem, you can tear that area up (with a verti-cutter or slicer), fertilize the lawn, and it will grow right back in. If you try to do that during the fall or spring months, there will be periods of time when the lawn isn’t growing, or delayed growth, and it could lead to more problems.”

Among weeds, crabgrass and yellow nutsedge are two of the most troublesome this time of year.

““I’m seeing a lot of crabgrass and yellow nutsedge and I blame it on the weather,” Hoyle said. “Yellow nutsedge loves flooded, compacted soils and because of periodic flooding around the state, I have seen a lot of areas that typically never have yellow nutsedge. It’s a weed to keep an eye out with the weather conditions as they have been.”

To control yellow nutsedge, look for products with the active ingredients halosulfuron or sulfrentrazone, he said.

Crabgrass that has already emerged can be treated with products that include the active ingredient quinclorac.

Hoyle noted that homeowners should be patient when applying herbicides to yellow nutsedge and crabgrass; it might take more than one application to control those weeds.

K-State’s Department of Horticulture and Natural Resources publishes a weekly horticulture newsletter with updated information on lawn care and other turfgrass issues. Residents may also contact their local extension agent.

Under Attack from Weeds

(By Jared Hoyle, KSU Turfgrass Research and Extension)

As a turfgrass manager, as soon as you think you have it under control… BAM, you are under attack. Just in a short period of time Manhattan has been under attack from weeds. Now many of these weeds are large and hard to control.

With all the rain earlier in the season there was standing water in many of the low areas of the research farm. The turf did not like it and eventually died. But what did like it was yellow nutsedge. I put up some information about this in the recent past but, it is everywhere and I am still getting phone calls about it so I wanted to direct you to the most recent post on controlling yellow nutsedge.

https://blogs.k-state.edu/turf/yellow-nutsedge-reported-across-ks/

Also, you can use glyphosate to treat yellow nutsedge in landscape beds but it only provides marginal control. Remember not to use glyphosate to treat yellow nutsedge in your turf.

Crabgrass galore! Slow to start but it is going strong now! Anywhere we didn’t put down a preemergent herbicide this year crabgrass has started to take over. Good thing there is options for control. Check out my earlier post for crabgrass options. Pay attention to control options for larger tillered crabgrass.

http://blogs.k-state.edu/turf/postemergent-crabgrass-control-2/


If it is not yellow nutsedge or crabgrass it is goosegrass. Back in early June, goosegrass emergence was reported across Kansas. Now the goosegrass is growing and going to be more difficult to control because it has tillered out. Make sure you make your follow-up applications when recommended and choose your control options that are effective on larger goosegrass.

If you have cool-season turfgrass then you can use fenoxaprop (Acclaim Extra), fluazifop (Fusilade II), tropramizone (Pylex), or MSMA (golf courses and sod farms only!).  You will have to do more than one application since the goosegrass is tillered out.  Sulfentrazone (Dismiss) is also effective on goosegrass if it has not tillered out yet so might want to go with another option since now the goosegrass is big.

For all you golf courses out there that have creeping bentgrass fairways it is going to be a little bit more difficult because the herbicides that work best tend to injure the turf.  1-Tiller or smaller can be controlled with fenoxaprop (Acclaim Extra) at 3.5 fl oz/A but you will need to re-apply every two weeks to make sure you are applying to small plants. This could be a follow-up option if new goosegrass starts to emerge before the season it over.

As crazy as it sounds a herbicide that has commonly been used for broadleaf weeds has shown control on goosegrass.  SpeedZone (2,4-D +dicamba + MCPP) has shown control but a follow up application is going to be needed 30 days after initial application. Pay attention to the temperature restrictions in this heat!

Tropramizone (Pylex) can be used on bentgrass at lower rates (0.25 fl oz/A) but definitely need a repeat application at 21 days

Now if you have bermudagrass or zoysiagrass then you can use Tribute TOTAL (thiencarbazone + foramsulfuron + halosulfuron).  Fusilade II and Acclaim Extra that works in cool-season grass can also be used on zoysiagrass.  If you mix these products with triclopyr (Turflon Ester Ultra or Triclopyr 4) then you will get better results.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

Information in this article is from Turfgrass Weed Control for Professionals.

Patton, A.J., M. Elmore, J. Hoyle, J. Kao-Kniffin, B. Branham, T. Voigt, N. Christians, A. Thoms, G. Munshaw, A. Hathaway, T. Nikolai, B. Horgan, L. Miller, X. Xiong, W. Kreuser, R. Gaussoin, D. Gardner, Z. Raudenbush, D. Li, P. Landschoot, D. Soldat, and P. Koch. 2019 Turfgrass Weed Control for Professionals. Purdue University Extension Publication. TURF-100. pp. 128.

Get your copy here – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=20239

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Postemergent Crabgrass Control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Today I was walking around the Rocky Ford Turfgrass Research Center in Manhattan, KS looking for an area to put out a postemergent crabgrass study and notice that the crabgrass on the research farm is all different stages.  It is important to know what stage the crabgrass is in to help with control.  That could determine your success in controlling it with postemergent herbicides

There are postemergent herbicide options out there for crabgrass control.  But depending on how big or how many tillers the crabgrass has will help you determine what product to use.  First, determine the size or stage of crabgrass you have present.

Here is a picture to show the tillering stages of crabgrass.

The smaller the crabgrass the easier it is to kill it.  The tillered crabgrass may take more than one application and higher rates so make sure you check the label for correct application rates and intervals.

  • dithopyr – Can provide control to crabgrass up to one tiller stage.  This product also has preemergence activity.
  • quinclorac – Can be applied on most cool- and warm-season turfgrass species.  This product controls crabgrass when it is one tiller or smaller or when it has four or more tillers.
  • mesotrione – Can be effective for crabgrass control but in most cases will take two applications at two week intervals. The label also states that applications must be made before the four tiller crabgrass stage.
  • topramazone – Similar to mesotrione, this product will require two applications at three week intervals. Use at higher rates on crabgrass that have greater than one tiller.
  • fenoxaprop – Are very effective in controlling crabgrass.  Label states that this product can be applied to annual grasses up to the five tiller stage. Remember not to tank mix with products that contain 2,4-D, antagonism can occur.

As one last reminder, do not apply post emergent herbicides outside the recommended temperature on the label.  This will increase the risk of turfgrass injury.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Weed Control Update

(By Jared Hoyle, KSU Turfgrass Research and Extension)

As I look back through blog posts from Spring time in previous years, I notice a repeated theme – Crabgrass, Knotweed and Wild Garlic.

So instead of “reinventing the wheel this year” and writing a new blog post I am going to post previous years posts for these weeds.  There is lots of great information about these weeds and how to control them. (Links to information below the photograph.)

This way I can focus on adding a weed to this list that is become more and more persistent in Kansas. (Stay tuned!)

Crabgrass

https://blogs.k-state.edu/turf/more-than-you-ever-want-to-know-about-preemergent-herbicides/

Photo credit – Auburn University Turfgrass – http://cses.auburn.edu/turfgrass-management/weed-identification/wild-garlic/

Wild Garlic

https://blogs.k-state.edu/turf/stinks-dont-it-wild-garlic-control-in-turfgrass/

Knotweed

https://blogs.k-state.edu/turf/not-your-fathers-knotweed/ 

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

Postemergent Crabgrass Control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Did you apply a preemergent herbicide this year and still have crabgrass? There are many different reasons you may have break through from a preemergent herbicide application.  If the turf is stressed and thin, along with over use of the turf and misapplications are some reasons you may be seeing crabgrass pop-up across many turfgrass areas.

Good news! There are some postemergent herbicide options out there for crabgrass control.  But depending on how big or how many tillers the crabgrass has will help you determine what product to use.  First, determine the size or stage of crabgrass you have present.

Here is a picture to show the tillering stages of crabgrass.

The smaller the crabgrass the easier it is to kill it.  The tillered crabgrass may take more than one application and higher rates so make sure you check the label for correct application rates and intervals.

  • dithopyr – Can provide control to crabgrass up to one tiller stage.  This product also has preemergence activity.
  • quinclorac – Can be applied on most cool- and warm-season turfgrass species.  This product controls crabgrass when it is one tiller or smaller or when it has four or more tillers.
  • mesotrione – Can be effective for crabgrass control but in most cases will take two applications at two week intervals. The label also states that applications must be made before the four tiller crabgrass stage.
  • topramazone – Similar to mesotrione, this product will require two applications at three week intervals. Use at higher rates on crabgrass that have greater than one tiller.
  • fenoxaprop – Are very effective in controlling crabgrass.  Label states that this product can be applied to annual grasses up to the five tiller stage. Remember not to tank mix with products that contain 2,4-D, antagonism can occur.

As one last reminder, do not apply post emergent herbicides when temperatures are greater than 85 deg F.  This will increase the risk of turfgrass injury.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

A Homeowner Step-By-Step Buffalograss Lawn Guide

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Buffalograss Lawn Calendar

For more information check out the Buffalograss Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1447

Buffalograss has become more popular in recent years due to its reputation as a low-maintenance grass. Buffalograss does require less water and fertilizer than our other turfgrasses but often has problems competing with weeds in eastern Kansas. Remember, buffalograss is a low-maintenance lawn and not a “No”-maintenance lawn.

Buffalograss is an open growing grass that will not shade the soil as well as most of our other turfgrasses. Weeds are often the result. A regular mowing schedule can reduce broadleaf weed problems as most broadleaves cannot survive consistent mowing. Those that do either have a rosette growing pattern (dandelions, shepherds purse) or are “creepers” (henbit, chickweed, spurge). Annual grasses such as crabgrass or foxtail can also be a problem. A good weed preventer (prodiamine, pendimethalin or dithiopyr) may be needed prevent problems.

March

Spot treat broadleaf weeds if necessary. The most important treatment for broadleaf weeds should be in late October to early November well after the buffalograss is dormant. Treatments are much more effective then than in the spring as the weeds are smaller and the weeds are sending energy, as well as the herbicide, to the roots. Treatments in March are to take care of any “escapes” missed in the fall spraying. Spray early enough in March that the buffalograss is still dormant. Look at the base of the plants to make sure there is no green. Treat on a day that is 50 degrees F or warmer. Rain or irrigation within 24 hours of application will reduce effectiveness.  Use a combination product such as Trimec, Weed-B-Gon or Weed-Out. Weed Free Zone is also good and will give quicker results under cool conditions.

April

Apply crabgrass preventer between April 1 and April 15, or apply preventer when the eastern redbud is in full bloom. If using a product with prodiamine (Barricade), apply two weeks earlier.  Crabgrass preventers must be watered in before they will work. Avoid using broadleaf herbicides as the buffalograss is greening up as injury can result. The buffalograss will not be killed but growth will slow making the buffalograss less competitive with weeds.

June

Fertilize with 1 lb. of nitrogen per 1,000 square feet during June. More applications will give a deeper green color, but can encourage weeds. If it is felt that a second application is needed, apply in July.

If grubs have been a problem in the past, apply a product containing imidacloprid by mid July. Imidacloprid can be applied as early as mid May if there are problems with billbugs or May beetle grubs. These products kill the grubs before they cause damage. They are effective and safe but must be watered in before they become active. Again, I would only treat if grubs have been a problem in the past. Note that the whole area may not need to be treated. The beetles that lay the eggs for the grubs are attracted to lights and moist soil and those areas are most likely to be infested.

Late-July through August

If you see grub damage, apply a grub killer. If imidacloprid has been applied or if grubs have not been a problem in the past, this should not be necessary. Grub killers must be watered in immediately.

Late October to Early November

Spray for broadleaf weeds if they are a problem. Look carefully as our winter annuals such as chickweed and henbit are small and easily overlooked. Use a product that contains 2,4-D as it increases effectiveness on dandelions. Treat on a day that is at least 50 degrees F. Rain or irrigation within 24 hours reduces effectiveness. Use the rates listed on the label for all products mentioned.

For more information check out the Buffalograss Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1447

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

A Homeowner Step-by-Step Guide to Bermudagrass and Zoysiagrass Lawns

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Earlier I posted the Homeowner Step-By-Step Guide to Cool-Season Lawns in Kansas so I decided that it would be good to go ahead and get the warm-season lawn calendar out there for everyone that is manageing zoysiagrass, bermudagrass.

The following is a lawn calendar for zoysiagrass and bermudagrass. Buffalograss, also a warm-season grass, but we will cover that separate because the management of buffalograss is a little different then zoysiagrass and bermudagrass.

For more information check out the Zoyisagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1451

For more information check out the Bermudagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=586

 

Zoysiagrass and Bermduagrass Lawn Calendar

March
Spot treat broadleaf weeds if necessary. Treat on a day that is 50 degrees F or warmer. Rain or irrigation within 24 hours of application will reduce effectiveness.

April
Apply crabgrass preventer between April 1 and April 15, or apply preventer when the eastern redbud is in full bloom. This year we are getting a little warmer sooner but remember this cold snap that we just had would have killed any crabgrass if it had germinated. If using a product with prodiamine (Barricade), apply two weeks earlier. Crabgrass preventers must be watered in before they will start to work.

May – August 15
Fertilize with 1 lb. of nitrogen per 1,000 square feet per application. Follow the recommendations on the bag. More applications will give a deeper green color, but will increase mowing and may lead to thatch buildup with zoysiagrass. Bermudagrass can also have problems with thatch buildup but thatch is less likely with Bermuda than zoysia. Bermudagrass – Use two to four applications. Zoysiagrass – Use one to two applications. Too much nitrogen leads to thatch buildup.

One Application: Apply in June.
Two Applications: Apply May and July.
Three Applications: Apply May, June, and early August.
Four Applications: Apply May, June, July, and early August.

Remember to look and see if you are using a quick release nitrogen source or a slow release nitrogen source.  If you use a quick release source then it is immediately available but only lasts a couple weeks.  Thats why you would have to make a couple of applications like it is listed above.  If you are going to use a slow release source it will tell you on the bag how long the product will last.  Therefore, you might not have to make as many applications.

So generally you want to use a total of 2 to 4lb. of nitrogen per 1,000 square feet per year for bermudagrass and 1 to 2 lb. of nitrogen per 1,000 square feet per year for zoysiagrass.

June
If grubs have been a problem in the past, apply a product containing imidacloprid by mid July. Imidacloprid can be applied as early as mid May if there are problems with billbugs or May beetle grubs. These products kill the grubs before they cause damage. They are effective and safe but must be watered in before they become active. June is a good time to core aerate a warm-season lawn. Core aeration will help alleviate compaction, increase the rate of water infiltration, improve soil air exchange and help control thatch.


Late-July through August
If you see grub damage, apply a grub killer. If Imidacloprid has been applied, this should not be necessary. Grub killers must be watered in immediately.

Late October
Spray for broadleaf weeds if they are a problem. Treat on a day that is at least 50 degrees F. Rain or irrigation within 24 hours reduces effectiveness. Use the rates listed on the label for all products mentioned.

For more information check out the Zoyisagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1451

For more information check out the Bermudagrass Lawns Publication at the KSRE Bookstore – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=586

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

A Homeowner Step-By-Step Tall Fescue and Kentucky Bluegrass Lawn Guide

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Homeowner Do-It-Yourself Lawn Calendar for Cool-Season Grasses

The following suggestions are for cool-season grasses such as Kentucky bluegrass or tall fescue. Zoysiagrass, bermudagrass, and buffalograss are warm-season grasses and require a different maintenance regime.

March
Spot treat broadleaf weeds if necessary. Treat on a day that is 50 degrees or warmer. Rain or irrigation within 24 hours of application will reduce effectiveness.

DSCN0010April
Apply crabgrass preventer (Or maybe even a little bit sooner this year) when redbud trees are in full bloom, usually in April. The preventer needs to be watered in before it will start to work. One-quarter inch of water will be enough to water in any of the products mentioned in this calendar.  Remember that a good, thick lawn is the best weed prevention and may be all that is needed.

May
Fertilize with a slow-release fertilizer if you water your lawn or if you receive enough rainfall that your turf normally doesn’t go drought-dormant during the summer. If there are broadleaf weeds, spot treat with a spray or use a fertilizer that includes a weed killer. Rain or irrigation within 24 hours of application will reduce effectiveness of the weed killer, but the fertilizer needs to be watered in. If you are using a product that has both fertilizer and weed killer, wait 24 hours after application before watering in.

June through Mid-July
Apply second round of crabgrass preventer by June 15 – unless you have used Dimension (dithiopyr) or Barricade (prodiamine) for the April application. These two products normally provide season-long control with a single application. Remember to water it in. If grubs have been a problem in the past, apply a product containing imidacloprid during the first half of July. This works to prevent grub damage. It must be watered in before it becomes active.

IMG_0563Late-July through August
If you see grub damage, apply a grub killer that contains Dylox. Imidacloprid is effective against young grubs and may not be effective on late instar grubs. The grub killer containing Dylox must be watered in within 24 hours or effectiveness drops.

September
Fertilize around Labor Day. This is the most important fertilization of the year. Water in the fertilizer.

November
Fertilize. This fertilizer is taken up by the roots but is not used until the following spring. Water in fertilizer. Spray for broadleaf weeds even if they are small. Broadleaf weeds are much easier to control in the fall than in the spring. Spray on a day that is at least 50 degrees. Rain or irrigate within 24 hours reduces effectiveness. Use label rates for all products!

For more information on Tall Fescue Lawns – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=1460 

For more information on Kentucky Bluegrass Lawns- https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=816

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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 me on twitter @KSUTurf.

Also, visit our facebook page www.facebook.com/KSUTurf

More than you ever want to know about preemergent herbicides

(by Jared Hoyle, KSU Turfgrass Research and Extension)

Ever year I write a blog, a newsletter article, send out a tweet and post on Facebook about applying preemergent herbicides for summer annual grass control. We are typically most concerned with crabgrass so I went back and searched through the blog posts and articles and believe it or not it is all still relevant information! Not much has changed, so for this article I am going to spotlight information across these articles and compare from when I originally wrote it.

Crabgrass emerging in bare ground earlier than turf

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Up first, Methods of Predicting Crabgrass Emergence! In this article I go over the different methods to predict when crabgrass emerges; calendar date, soil temperatures, forsythia blooms, growing degree days. Like last year we have had a fluctuating Spring. In the article from March 14, 2017 I stated that it was 80 deg F on the 12th and was snowing just a couple days before. Sound familiar? Refresh yourself on the different methods and know its not too late to get preemergence herbicides out.

https://blogs.k-state.edu/turf/methods-of-predicting-crabgrass-emergence/

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Next article is for all you golf course turfgrass managers. Preemergence Weed Control in Bentgrass Putting Greens. This article was also from March 2017 and I went through what preemergent herbicides are available to use on bentgrass putting greens. The list of herbicides was from the Turfgrass Weed Control for Professionals 2017 Manual (https://mdc.itap.purdue.edu/item.asp?Item_Number=TURF-100). Going through the 2018 edition…. Guess what again? Not much has changed for use on putting greens but I would encourage you to check out the manual and read the “Tips for Herbicide Use on Golf Course Putting Greens” section on page 108.

https://blogs.k-state.edu/turf/preemergence-weed-control-in-bentgrass-putting-greens/


And now one of my favorite quotes from Benjamin Franklin “An ounce of prevention is worth a pound of cure”. This was the lead in for talking about why preemergent herbicides are worth it! This article talks about what weeds preemergent herbicides work on, how they work, and the growth stages of crabgrass. To “round-up” the article I put a list of options out there, the weeds these preemergent herbicides control and some concerns/comments. One thing that I did not list is the combination products. I only listed the single active ingredients.   There are many combination products as well. (Maybe that will be the next blog post – Combination Preemergent Herbicides.)

https://blogs.k-state.edu/turf/an-ounce-of-prevention-is-worth-a-pound-of-cure-by-benjamin-franklin-that-goes-for-preemergence-herbicides-too/

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***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.***

Keep it mowed and let mother nature take control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

One of the most common weed control recommendations for winter annual weeds is “keep it mowed and let them die because of the warmer weather”.  Well right now it is March 30th and it is prime winter annual weed growing weather.  Yeah, it might warm up in the next week but what if this is what we recommended in February when we have a week of 75 deg F weather.  We would have been waiting about 2 months before mother nature would have taken care of that weed problem.  So here is some information about winter annual weeds and control.

The plant with the little tube shaped purple flowers that have been showing up turfgrass is called henbit. If you are not sure this is what you have, check the stems. If they are square rather than round, you have henbit. Square stems are an indication that it is in the mint family.  Henbit is a winter annual broadleaf with kidney shaped leaves, opposite arranged, with rounded teeth on the leaf margin.  The upper leave surround the stem.  It really likes disturbed, moist areas in turf and landscape beds.  Don’t get it mixed up with purple dead nettle or ground ivy, they are similar looking weeds. Most broadleaf weed herbicides are effective.

A plant that also is low growing but has round stems and tiny white flowers is chickweed. Chickweed is also a winter annual and starts to grow in the fall. They spend the winter as small plants and so most people do not pay much attention to them until they start to flower in the spring.

Remember, these are winter annuals that will die as soon as the weather turns hot. You can keep the turf mowed and you can let nature take its course. As you can see this year it got warm, then cold, then snowed, then warm again, dry and now 50’s – low 60’s and raining.  So waiting may not be an option for golf courses, parks, sports complexes, and lawns. We may need a jump start to get rid of those weeds.

Ok so here is a scenario.  We wait and let the warm weather kill off the winter annual weeds.  Now there is a void in the turf. What happens in voids in our turf as it warms up?  Crabgrass starts to germinate.  Hope you got your preemerge herbicide out for crabgrass!

Fall is obviously the best time to kill broadleaf weeds but these weeds will germinate throughout the Fall to Spring.  The majority germination in October but they will continue to germinate through the spring especially when we have those warm fall and winter days.  So a Fall application in November may not get complete control because more will germinate after that application.  Thats why a Spring application may be needed as well to clean up these weeds along with some dandelions that may have also survived.  Most broadleaf weed herbicides are effective especially ones that are three-four way mix.  FYI, at this time the weeds are more mature and harder to control.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

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