Kansas State University

search

K-State Turfgrass

Author: jahoyle

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

Bentgrass Declining? It’s from Western Europe, You live in Kansas

(By Jared Hoyle, KSU Turfgrass Research and Extension)

The past couple weeks have been a struggle to grow bentgrass.  Some areas in Kansas are getting rain but others are not.  The rains have been localized and here at the Rocky Ford Turfgrass Research Center in Manhattan we keep missing the isolated showers.

I know some other golf course are in the same place as we are and it has been a struggle to keep bentgrass alive.  Well, I dug through the blog and found a post from Dr. Jack Fry about bentgrass management in the summer.  Dr. Fry leads of the article with..

“In the midst of a summer with 100+ F temperatures, it’s worthwhile to consider some of creeping bentgrass’s preferences and management strategies that might be helpful to reduce its stress, and yours.  See, the thing about creeping bentgrass on putting greens is….”

Click below to find out more about bentgrass management in the summer.

http://blogs.k-state.edu/turf/bentgrass-declining-its-from-western-europe-you-live-in-kansas-by-dr-fry/

Don’t miss the Kansas Turfgrass Field Day August 2nd in Manhattan!

(By Jared Hoyle, KSU Turfgrass Research and Extension)

The Kansas Turfgrass Field Day will be held Thursday, August 2 at the Rocky Ford Turf Research Center in Manhattan.

You can register online at https://2018turfday.eventbrite.com

The field day program is designed for all segments of the turf industry – lawn care, athletic fields, golf courses, and grounds maintenance. Included on the program are research presentations, problem diagnosis, commercial exhibitors, and equipment displays. There will be time to see current research, talk to the experts and get answers to your questions.

Pesticide recertification credits in 3A and 3B are available, as well as GCSAA education points.

Would you like to be a vendor at field day?

For more information check out The Kansas Turfgrass Foundation Website – http://www.kansasturfgrassfoundation.com/annual-ktf-field-day.html

A Hard Winter on Bermuda

By Dr. Jack Fry and Mingying Xiang, (KSU Turfgrass Teaching, Research and Extension)

It was a hard winter for bermudagrass, and we saw extensive winter injury in Kansas – even to cultivars that we usually consider winter hardy. There is a trial at the Rocky Ford Turfgrass Research Center in Manhattan in which we’re evaluating experimental bermudagrasses from the breeding program at Oklahoma State University lead by Dr. Yanqi Wu (Fig. 1). Here are averages (of three replicated plots) of winter injury for standard cultivars included in the trial when we rated them on May 25: Tifway (100%); Latitude 36 (80%); Northbridge (75%); and Patriot (70%). The total loss of Tifway isn’t unusual, as it has poor cold hardiness. However, the severity of this winter caused severe damage to cultivars we previously thought were relatively hardy, including Latitude 36 and Northbridge. There is some good news. Several experimental grasses included in this trial experienced almost no winter injury, which bodes well for release of grasses with good cold hardiness in the future.

Fig. 1. Dr. Yanqi Qu and Mingying Xiang evaluate Oklahoma State’s experimental bermudas growing in 5 by 5 ft plots at Rocky Ford on May 25. Notice that many have extensive winter injury, while others are showing good recovery.

We heard from turf professionals in the state who indicated that injury was severe in some cases, and minimal in others – microclimates and differences in exposure likely had a lot to do with that.   Yukon bermudagrass, a seeded cultivar, had almost no winter injury at Wildcat Creek Golf and Fitness in Manhattan (Fig 2). This was impressive considering it was seeded in 2017.

Fig. 2. Yukon Bermuda, seeded in the summer of 2017 by Kevin Fateley at Wildcat Creek Golf and Fitness in Manhattan, KS showed very good recovery in May and almost no winter injury.

Fortunately, it has been a great summer for recovery. High temperatures above 100 F and lows in the mid 70s speed the growth and spread of bermuda. Unfortunately, it’s been another one of those hard summers for cool-season grasses. Here we are in Kansas trying to cope with the wrath of extreme winter and summer temperatures – been here, done this.

 

Yellow Nutsedge Control

(By Jared Hoyle, KSU Turfgrass Research and Extension)

As I talk to turfgrass professionals across the state I hear that some are getting plenty of rain while others are getting none. This time of the year we think that if we are getting some precipitation we will have yellow nutsedge popping up everywhere. Well that is not always true. Yellow nutsedge does favor moist soils but it can also grow in well-drained sites.

One of the easiest ways to identify yellow nutsedge is by a couple special features;

  • erect
  • persistant
  • yellow inflorescence
  • gradually tapering leaves to a sharp point
  • tubers not in chains
  • triangular stem

To control yellow nutsedge, if you can get applications out before tuber production then you will see increased control.  But beware, yellow nutsedge will continue to grow as long as the environment is favorable for growth, so more than one application maybe necessary.

If using a herbicide application timing is critical.  During mid summer yellow nutsedge starts making tubers and if you apply herbicides before tuber production you will get better control.  If you wait until the yellow nutsedge is big and starting to make tubers then you will be playing catch-up all year. So sooner is better.  Don’t wait for it to get too big.

Here are some options for yellow nutsedge control for turfgrass professionals;

  • sulfentrazone
  • halosulfuron
  • iodosulfuron
  • mesotrione
  • bentazon
  • triflozysulfuron
  • flazasulfuron
  • sulfosulfuron

There are many different products out there that contain these active ingredients so just make sure you have an active ingredient that has yellow nutsedge control! Also make sure you check for turfgrass tolerances.

****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

Return of the Goathead – Puncturevine

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Return of the Goathead – Sounds like a horror movie! Well, right now I do feel like it is “Return of the Goathead”. Just about everywhere I look I see a goathead. Goathead is also known as puncturevine (Tribulus terrestris). It is a summer annual broadleaf weed that can cause headaches for many people.

 

This weed is a prostrate mat-forming weed that can produce many burs with sharp spines. This weed if invading a lawn, athletic field, playground and parks can cause injury to children and animals if they fall on or step on the sharp spines. It can also be found in disturbed areas as fields, pastures and roadsides. Good news is that many of the broadleaf herbicides are effective.

 

****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

Stinks… Don’t It! – Wild Garlic Control In Turfgrass

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Garlic has a very distinct and pungent smell, stinks… don’t it!  But did you know there are benefits to eating garlic? It is highly nutritious but has very few low calories, it can help combat sickness, it can reduce blood pressure, and more.

Around Manhattan I have been seeing a lot of wild garlic in lawns. Now don’t go out and eat that wild garlic. We are now talking about the turfgrass weed wild garlic and not the garlic you eat.

Wild garlic (Allium vineale) is more obvious in the winter and early spring because this weed will grow above the turfgrass canopy and is easily noticed. Sometimes it can be easily confused with wild onion and star-of-Bethlehem.

Wild garlic is a perennial bulb that has a grass like appliance. It emerges in late winter and early spring. The leaves are straight and smooth. The way to tell the difference between wild garlic wild onion is by tearing the stem to see if it is hollow or solid. It if is hollow then it is wild garlic. If it is a solid stem then it could be wild onion.

This weed tolerate a wide range of soil conditions but I have noticed it more in low maintenance areas.

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

Control of wild garlic in cool-season turfgrass is more difficult then in warm-season turfgrasses.  For fair control use 2,4-D or one of the many combinations of 2,4-D, MCPP and dicamba.  This products have shown to have limited control.  The ester formulations of 2,4-D are more effective than amine formulations.  Applications in the late fall and early spring when there is adequate foliage is best.  To increase uptake, mowing before application may help.

In warm-season turfgrass metsulfuron or metsulfuron + sulfentrazone and sulfosulfuron provide very effective control.  Applying these products in late March early April on a warm day above 50 deg F when there is good soil moisture will increase efficacy.

If you got wild garlic, right now is the time to go out and get it.  Not to mention if you have any other broadleaf weeds you will get some control of those as well!

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

Not Your Father’s Knotweed

(By Jared Hoyle, KSU Turfgrass Research and Extension)

For the past couple years I have posted on prostrate knotweed (Polygonum aviculare) control in turfgrass systems.  Guess what… it is that time of year again.  I have been seeing knotweed germinate all across campus and in areas where turf is thin.  Knotweed can grow in compacted soils where turf can’t survive. So after you get control of that knotweed make sure you aerify to relieve the compaction (Check out my recent post on aerification – http://blogs.k-state.edu/turf/new-aerating-your-lawn-ksre-publication/) and get some healthy turfgrass growing.

There are going to be some new products coming to the market soon that we have tested on prostrate knotweed that have shown excellent control.  So keep a lookout for new broadleaf herbicides (Hopefully they will be out either late this year or early next year).  When they hit the market you will hear all about it and next year when I post about knotweed control hopefully they will be released and I can add it to the list!

If you didn’t get your preemerge out in the fall for control and you have a history of knotweed it is time to go out and attack the knotweed and other broadleaf weeds you have lingering around.  These weeds are easier to control now when they are young compared to when they get mature.

Below is the Knotweed Control Turfgrass Selfie Series Video I did last year but here are the take home messages;

  • Early germinating summer annual
  • Likes compacted soils/flooded areas
  • 2,4-D = fair control
  • 2,4-D + triclopyr or dicamba = excellent control
  • metsulfuron can be used in warm-season turf
  • PRE applications must be done in the Fall

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