Kansas State University

search

K-State Turf and Landscape Blog

Tag: zoysiagrass

Zoysiagrass Seedhead Suppression

Posted on by Brooke Garcia

By Dr. Jack Fry

Below-average spring temperatures and a lot of cloud cover haven’t been beneficial for growth of warm-season grasses. Nevertheless, days are getting longer, and Meyer zoysia began to produce seedheads in northeast Kansas last week. Significant work was done at K-State on zoysia seedhead suppression by Dr. Jared Hoyle, along with Dr. Aaron Patton at Purdue University. Seedheads on Meyer have a purple tone to them, but after mowing, the seed stalks leave an undesirable white cast on golf course fairways and tees. The plant growth regulator ethephon (trade name Proxy) is effective at suppressing zoysia seedheads if it is applied at the proper time the previous autumn. Manoj Chhetri, a current Ph.D. student, is working on better refining application time for Proxy to suppress zoysia seedheads. The Golf Course Superintendents Association of America, along with the Heart of America Golf Course Superintendents Association and Kansas Turfgrass Foundation, are sponsoring this zoysia seedhead suppression research that is summarized in Golf Course Management magazine (link below).

https://www.gcmonline.com/course/environment/news/zoysiagrass-seedheads

Seedheads are just beginning to emerge on Meyer zoysiagrass in Olathe, KS. Best suppression of the seedheads occurs when the growth regulator Proxy is applied in autumn.

Large Patch Evaluation Study Update

Posted on by Brooke Garcia

By: Manoj Chhetri

With temperatures cooling down and days being shorter, we are already starting to see warm-season grasses, including zoysiagrass, going to sleep. At the Rocky Ford Turfgrass Research Center, located in Manhattan, KS, we have shut down the irrigation in warm-season plots.

Our zoysiagrass in the large-patch tolerant breeding plot is not cooperating with us as much as we wanted. We inoculated the field in mid-September with fresh Rhizoctonia pathogen and kept the field pretty wet to encourage fungi to flourish. However, to our dismay, we did not see much of the disease activity, except in a few poor drainage spots. With disease research, it is the type of research where we want disease pathogens to have no mercy on us. We are impatiently waiting for spring, which in fact is a more favorable time of the year for large patch activity.

We are hopeful that we have at least one or two new zoysiagrass progeny that possess greater large patch tolerance. Again, it is hard to make comparison and evaluate when we don’t have disease pressure. So far, we have narrowed down to 10 best progeny out of 60. On the positive note, we have seen more disease pressure on our non-selected progeny than in our top-ten selected progeny. This tells us that we did a good job on choosing those ten-best progeny.

This project is aiming to develop a large patch tolerant zoysiagrass that can significantly reduce cost on fungicides and protect the environment. It is a collaborative project between Texas A & M and K-State University.

Pictured Above: Zoysiagrass progeny evaluated in large patch disease environment.

Pictured Above: One of the zoysiagrass progeny showing large patch in one inoculated half (right side) and fungicide treated cleaner side on other half (left side).

Zoysia breeding line evaluation work continues

Posted on by kennelly

(Megan Kennelly, KSU Plant Pathology)

KSU continues its work with the turf breeding team at Texas A&M and colleagues at Purdue. We recently inoculated some breeding lines with the large patch pathogen. We grow the fungus on sterilized oats then bury it just under the thatch layer. Sometimes we see symptoms in fall, but often we do not see them until spring. Scientific research takes a lot of patience :). In the meantime, we are keeping the plots moist to foster fungal growth.

In the meantime, large patch is active especially in wet areas:

Take note of these areas. It’s too late to fertilize zoysia now, but when spring comes around a bump of slow-release N may prompt recovery. In the meantime there may be actions you can take to improve drainage.

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

Posted on by Brooke Garcia
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.

Rethinking Zoysiagrass for Home Lawns

Posted on by Brooke Garcia

Kansas State University teamed with Texas A&M to develop a new cultivar of zoysiagrass called Innovation, that’s suitable for lawns and golf courses. Pictured is Ted Wilbur (left), owner of Sod Shop in Wichita, Kansas and Jack Fry, horticulture professor at Kansas State University. Wilbur was the first to grow Innovation commercially in Kansas.

K-State, Texas A&M develop new cold-hardy variety for home landscapes and golf courses

OLATHE, Kan. – Who doesn’t love the look and feel of a soft, green carpet of grass underfoot? Even better if it’s resistant to pests and requires less fertilizer than other grasses. A Kansas State University professor believes that zoysiagrass can fit the bill for home landscapes – even in Kansas and surrounding states.

Zoysiagrass is well known as a warm-season grass commonly grown across southern tier states for its dense, weed-resistant and slow-growing nature (think less mowing), plus it requires about half the water needed for cool-season grasses typically grown in the nation’s midsection.

Those who choose to grow zoysia should be aware, however, that as a warm-season grass, it goes dormant and turns brown in mid-October and may not green up again until late April.

“The determining factor for whether any warm-season grass that can be used here is winter survival,” said Kansas State University horticulture professor Jack Fry.

Kansas and other states across the middle of the country are in what’s called a transition zone, where both warm- and cool-season grasses can grow but weather extremes can prove challenging and sometimes injure or kill the grass. In order to improve on a longtime favorite zoysia called Meyer, Fry and his K-State colleagues teamed with Texas A&M Agrilife researchers to develop a new zoysia cultivar.

Their aim was to develop a cultivar that is as cold-tolerant as Meyer for areas in the transition zone, but also to offer improved characteristics, such as finer leaf blades and even better density which blocks out weeds.

The K-State team worked with Ambika Chandra, associate professor at Texas A&M, to develop a new hybrid that was ultimately named Innovation. The new hybrid can withstand the cold that can sometimes blanket the central U.S. as well as Meyer does, but also exhibits better quality, meaning it has a darker green color, finer leaf blades, better density and good uniformity.

Zoysiagrass is already widely used on golf course tees and fairways in Kansas and across the transition zone, but less so on home lawns, Fry said. When drought water restrictions come about, however, it’s a good choice for home lawns.

Zoysia, and especially newer cultivars like Innovation, also require less fertilizer or pest treatments to stay healthy than typical cool-season grasses such as tall fescue or Kentucky bluegrass.

To develop the new cultivar, the researchers used traditional plant breeding, crossing cold-hardy types with other southern-adapted types that offered high density and finer-textured leaf blades.

That density results in almost no herbicides being needed during the growing season, Fry said.

To get from initial crosses – about 1,500 in all – to the final product took about 13 years, Fry said. Along the way from those initial crosses, 35 looked promising, so were planted in 5-foot by 5-foot plots in Kansas and Texas and evaluated by the researchers, who then narrowed the list to seven.

Those top seven hybrids were tested at additional sites across the transition zone in Missouri, Oklahoma, North Carolina, Tennessee and Virginia. The result is Innovation, which was released for commercial growth and sales in 2015. It is currently available via licensed distributors through a company called Sod Solutions, which has sub-licensed production to 15 sod producers in eight states.

What’s next? A new phase of the K-State-Texas A&M research is under way which aims to identify grasses that have superior resistance to a disease called Large Patch, and there may even be types that are promising for use on golf greens, too, Fry said.

Post featured by: https://www.ksre.k-state.edu/news/stories/2019/05/zoysia-for-home-lawns.html

——-

More information about zoysiagrass is available at

https://www.bookstore.ksre.ksu.edu/pubs/mf683.pdf

or in a Clemson University fact sheet, https://hgic.clemson.edu/factsheet/zoysiagrass/

Weekend Warrior Turfgrass Lawn Care

Posted on by jahoyle

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Finally I think we have turned the corner into Spring.  With that, I see more and more of my neighbors, and myself, working in the yard.  I get excited when the turf starts to turn green.  But before I get too carried away I want to get out on the right foot and planning is everything.  To help help you plan out your lawncare program below are monthly calendars for tall fescue, Kentucky bluegrass, buffalograss, bermudagrass and zoysiagrass.

Bermudagrass and Zoysiagrass Lawns

https://blogs.k-state.edu/turf/a-homeowner-step-by-step-guide-to-bermudagrass-and-zoysiagrass-lawns/

Buffalograss Lawns

https://blogs.k-state.edu/turf/a-homeowner-step-by-step-buffalograss-lawn-guide/

Tall Fescue and Kentucky Bluegrass Lawns

https://blogs.k-state.edu/turf/a-homeowner-step-by-step-tall-fescue-and-kentucky-bluegrass-lawn-guide/

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

Posted on by jahoyle

(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

Homeowner Do-It-Yourself Lawn Calendar for Warm-Season Grass

Posted on by jahoyle

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Last week I got a lot of good feed back on the Homeowner Do-It-Yourself Lawn Calendar for Cool-Season Grasses 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 or buffalograss.

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.

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.

 

Buffalograss Lawn Calendar

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.

It is as simple as that!  Enjoy!

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

Time to Think About Managing Your Warm-season Home Lawn

Posted on by jahoyle

Time to Fertilize Warm-Season Grasses    

    June is the time to fertilize warm-season lawn grasses such as bermudagrass, buffalograss, and zoysiagrass. These species all thrive in warmer summer weather, so this is the time they respond best to fertilization. The most important nutrient is nitrogen (N), and these three species need it in varying amounts.

buffalograss fairway

    Bermudagrass requires the most nitrogen.  High-quality bermuda stands need about 4 lbs. nitrogen per 1,000 sq. ft. during the season (low maintenance areas can get by on 2 lbs.). Apply this as four separate applications, about 4 weeks apart, of 1 lb. N per 1,000 sq. ft. starting in early May. It is already too late for the May application, but the June application is just around the corner. The nitrogen can come from either a quick- or slow-release source. So any lawn fertilizer will work.  Plan the last application for no later than August 15. This helps ensure the bermudagrass is not overstimulated, making it susceptible to winter-kill.

    Zoysiagrass grows more slowly than bermudagrass and is prone to develop thatch.   Consequently, it does not need as much nitrogen. In fact, too much is worse than too little. One and one-half to 2 pounds N per 1,000 sq. ft. during the season is sufficient. Split the total in two and apply once in early June and again around mid-July. Slow-release nitrogen is preferable but quick-release is acceptable.  Slow-release nitrogen is sometimes listed as “slowly available” or “water insoluble.”

IMG_0670

    Buffalograss requires the least nitrogen of all lawn species commonly grown in Kansas. It will survive and persist with no supplemental nitrogen, but giving it 1 lb. N per 1,000 sq. ft. will improve color and density. This application should be made in early June. For a little darker color, fertilize it as described for zoysiagrass in the previous paragraph, but do not apply more than a total of 2 lb. N per 1,000 sq. ft. in one season. Buffalograss tends to get weedy when given too much nitrogen. As with zoysia, slow-release nitrogen is preferable, but fast-release is also OK. As for all turfgrasses, phosphorus and potassium are best applied according to soil test results because many soils already have adequate amounts of these nutrients for turfgrass growth. If you need to apply phosphorus or potassium, it is best to core aerate beforehand to ensure the nutrients reach the roots. 

Thatch Control in Warm-Season Lawns      

    Thatch control for cool-season lawn grasses such as bluegrass and tall fescue is usually done in the fall but now is the time we should perform this operation for warm-season turfgrasses such as bermudagrass and zoysiagrass. Because these operations thin the lawn, they should be performed when the lawn is in the best position to recover.  For warm-season grasses that time is June through July. Buffalograss, our other common warm-season grass, normally does not need to be dethatched.

IMG_0024

    When thatch is less than one-half inch thick, there is little cause for concern; on the contrary, it may provide some protection to the crown (growing point) of the turfgrass. However, when thatch exceeds one-half inch in thickness, the lawn may start to deteriorate. Thatch is best kept in check by power-raking and/or core-aerating. If thatch is more than 3/4 inch thick, the lawn should be power-raked. Set the blades just deep enough to pull out the thatch. The lawn can be severely damaged by power-raking too deeply. In some cases, it may be easier to use a sod cutter to remove the existing sod and start over with seed, sprigs or plugs.  If thatch is between one-half and a 3/4- inch, thick, core-aeration is a better choice.

IMG_1534

    The soil-moisture level is important to do a good job of core-aerating. It should be neither too wet nor too dry, and the soil should crumble fairly easily when worked between your fingers. Go over the lawn enough times so that the aeration holes are about 2 inches apart. Excessive thatch accumulation can be prevented by not overfertilizing with nitrogen. Frequent, light watering also encourages thatch. Water only when needed, and attempt to wet the entire root zone of the turf with each irrigation.

    Finally, where thatch is excessive, control should be viewed as a long-term, integrated process (i.e., to include proper mowing, watering, and fertilizing) rather than a one-shot cure. One power-raking or core-aeration will seldom solve the problem.

New Fine-Textured, Cold-Hardy Zoysiagrass on the Horizon

Posted on by jahoyle

‘Meyer’ zoysiagrass was released in 1952, and is still widely used in the transition zone due, in large part, to its excellent cold hardiness. However, as good as Meyer is, it has limitations, including a medium coarse leaf texture and inferior density compared to Zoysia matrella-type cultivars. In 2004, researchers at K-State and Texas A&M AgriLife Research-Dallas began working together to develop dense, fine-textured zoysiagrasses that are as cold hardy as Meyer. Eleven years later, the first zoysiagrass from this effort, KSUZ 0802 (a formal name is forthcoming), has been approved for release by K-State, and is expected to be approved for release by Texas A&M this autumn.

KSUZ 0802 is a fine-textured, cold-tolerant zoysiagrass hybrid co-developed by Texas A&M AgriLife Research, Dallas, TX and the Kansas Agricultural Experiment Station, Manhattan, KS. KSUZ 0802 is a F1 interspecific hybrid developed in 2001 from a cross between Z. matrella (L). Merr. cv. ‘Cavalier’ and an ecotype of Z. japonica Steud. named ‘Anderson 1’, a derivative of ‘Chinese Common’ which was collected from rough areas at Alvamar Golf Course in Lawrence, KS. Cavalier is a high quality Z. matrella cultivar, but lacks the hardiness to be used in the upper transition zone. By crossing it with Chinese Common, which is cold hardy, we have created a cultivar that has Z. matrella-like quality, but with good cold hardiness. KSUZ 0802 must be propagated vegetatively.

fig1 zoysia

Initially, over 800 individual, genetically different hybrids were developed at Texas A&M AgriLife Research – Dallas in 2001. Grasses were planted in Manhattan, KS in 2004 and evaluated for quality and winter survival between 2004 and 2006. KSUZ 0802 was one of 31 hybrids selected for further evaluation at Manhattan in 2007 and 2008 under golf course conditions. These 31 were later narrowed to 7 hybrids, including KSUZ 0802, which were evaluated at nine locations in the transition zone under typical lawn or golf course fairway management conditions from 2009 to 2012. These locations were Wichita and Manhattan, KS; Columbia, MO; Fletcher and Jackson Springs, NC; Stillwater, OK; Knoxville, TN; Virginia Beach, and Blacksburg, VA; and Dallas, TX.

KSUZ 0802 has repeatedly demonstrated cold hardiness equivalent to Meyer in replicated field plot research (Fig. 1). Following a severe winter in 2013 in Manhattan, KS, KSUZ 0802 and Meyer had >99% survival; conversely, ‘Empire’ (Z. japonica) had 78% survival, ‘Zeon’ (Z. matrella) had 72% survival, and a large number of experimental Z. matrella selections had <50% survival (Thompson et al. 2013). Freezing tolerance studies conducted under controlled conditions at K-State showed that KSUZ 0802 had an LT50 (lethal temperature that kills 50% of the tillers) that was statistically similar to Meyer in two consecutive winters (Okeyo et al., 2011). Observed LT50 ranged from – 8.4 to – 10.3º C (17 to 14 º F) for KSUZ 0802 and from – 10.7 to – 12.0º C (13 to 10 º F) for Meyer. Based upon the results from research, KSUZ 0802 can be used as far north as zone 6a on the USDA Plant Hardiness Zone Map (http://planthardiness.ars.usda.gov/PHZMWeb/).

fig2

In general, KSUZ 0802 has a finer leaf texture and better density relative to Meyer, which results in better overall turf quality (Fig. 2 and 3). Average turf quality of KSUZ 0802 (average rating of 6.1 on a 1 to 9 scale) was higher than Meyer (average rating of 5.5) maintained at lawn height in Wichita, Kansas; Jackson Springs, NC; Stillwater, OK; Dallas, TX; and Blacksburg, VA. At fairway height, quality of KSUZ 0802 (average of 6.9) was superior to Meyer (average of 5.6) at the two locations it was evaluated – Manhattan, KS and Stillwater, OK.

fig 3

To summarize aforementioned results, and other research that has been with KSUZ 0802, its freezing tolerance, spring green-up and fall color retention are equivalent to Meyer, but it has a finer leaf texture than Meyer. KSUZ 0802 is also superior to Meyer for turfgrass quality and resistance to bluegrass billbug (Sphenophorus parvulus) damage. KSUZ 0802 is well suited for use on golf course fairways and tees, home lawns, and other recreational areas in the transition zone. It is currently under evaluation by sod growers in Kansas, Oklahoma, Texas, Illinois, Indiana and North Carolina. If you have questions about KSUZ 0802, or interest in producing it, contact either Jack Fry (jfry@ksu.edu) or Ambika Chandra (a-chandra@tamu.edu).

Acknowledgements

Funding tosupport the development of KSUZ 0802 came from a number of sources, including the Kansas Agricultural Experiment Station, Texas A&M AgriLife Research, the Kansas Turfgrass Foundation, the Heart of America Golf Course Superintendents Association, the Kansas Golf Course Superintendents Association, and the Kansas Golf Association. also acknowledge others who contributed to this research: Genovesi, Meghyn Meeks, and Milt Engelke, Texas A&M AgriLife Research; Qi Zhang,Okeyo, Jason Griffin, and Linda Parsons,-State; Justin Moss, Oklahoma State Univ.; Erik Ervin, Virginia Tech; Xi Xiong, Univ. of Missouri; Susana Milla-Lewis, North Carolina State Univ.; andBrosnan, Univ. of Tennessee. you!

(Jack Fry and Ambika Chandra)