Kansas State University

search

K-State Turfgrass

Category: Environment

Fall aerification to reduce problems in 2018

Got thatch?

If you are not sure what the thatch situation is on a site you manage, go take a look. Take a trowel, pocket knife, or soil probe, and poke around. If it’s starting to build up in your cool-season turf, take action now. You don’t want a thatch problem to bite you in summer 2018.

Here are some tips in this Fact Sheet about Thatch

Similarly – does your putting green soil look like a layer cake?

As we’ve said before here, a suboptimal rootzone is a pre-existing condition in putting greens.

Take advantage of this great fall weather to do all you can to promote healthy roots in 2018.

Time to fertilize cool-season turfgrass

(By Jared Hoyle, KSU Turfgrass Research and Extension)

September is almost here and that means it is prime time for to fertilize your tall fescue or Kentucky bluegrass lawns. If you could only fertilize your cool-season grasses once per year, this would be the best time to do it.

These grasses are entering their fall growth cycle as days shorten and temperatures moderate (especially at night). Cool-season grasses naturally thicken up in the fall by tillering (forming new shoots at the base of existing plants) and, for bluegrass, spreading by underground stems called rhizomes. Consequently, September is the most important time to fertilize these grasses.

Apply 1 to 1.5 pounds of actual nitrogen per 1,000 square feet. The settings recommended on lawn fertilizer bags usually result in about 1 pound of nitrogen per 1,000 square feet. We recommend a quick-release source of nitrogen at this time. Most fertilizers sold in garden centers and department stores contain either quick-release nitrogen or a mixture of quick- and slow-release. (We will talk about slow release in a later article.)

The second most important fertilization of cool-season grasses also occurs during the fall. A November fertilizer application will help the grass green up earlier next spring and provide the nutrients needed until summer. It also should be quick-release applied at the rate of 1-pound actual nitrogen per 1,000 square feet.

So total you only want to use up to 3 lbs of actually nitrogen per 1,000 square feet over September, October and November.

Here are some different ways you can apply the quick release nitrogen source;

Method 1 (Totaling 3 lbs of actually nitrogen per 1,000 square feet)

  • September – 1 lbs of actual N/1,000 square feet
  • October – 1 lbs of actual N/1,000 square feet
  • November – 1 lbs of actual N/1,000 square feet

Method 2 (Totaling 3 lbs of actually nitrogen per 1,000 square feet)

  • September – 1.5 lbs of actual N/1,000 square feet
  • November – 1.5 lbs of actual N/1,000 square feet

Method 3 (Totaling 2 lbs of actually nitrogen per 1,000 square feet)

  • September – 1 lbs of actual N/1,000 square feet
  • November – 1 lbs of actual N/1,000 square feet

Click here for the Kansas Lawn Fertilizing Guide – https://www.bookstore.ksre.ksu.edu/Item.aspx?catId=545&pubId=10639

Always make sure your pride your fertilizer evenly!!!!  You don’t want this to happen.

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

K-State Radio Network – Overseeding Cool-Season Lawns

(By Jared Hoyle, KSU Turfgrass Research and Extension)

For this week’s horticulture segment, K-State turfgrass specialist Jared Hoyle talks about taking the preliminary steps now for overseeding a cool-season lawn this fall.

Click the link below for K-State Research and Extension Agriculture Today Radio Program hosted by Eric Atkinson.

Human health – not just plant health! Stay hydrated out there and avoid heat stress.

On this blog we are usually talking about plant health, but here’s a quick switch to human health. We want all of our Kansas green industry folks to stay healthy and safe in the summer heat.

You already know this, but sometimes it is worth reminding ourselves that heat stress and dehydration can be very serious. A friend-of-a-friend of mine got very dehydrated once on a camping adventure, and she was very sick for several days (dizzy, vomiting).

This link has some common-sense tips:

http://online.ksre.ksu.edu/tuesday/announcement.php?id=35357

Take extra care of new crew members who are not used to the heat. For one thing, those folks are less used to it. Second, a new crew member may feel the need to just buck up and take it and be afraid to speak up that they need some shade or a water break. So keep an eye on everyone, but especially those that may be more vulnerable.

Take Advantage of Breaks in Summer Heat for Putting Green Management

By Jack Fry

Looks like we’ve got a short-term period of cooler temperatures over the next several days.  Midsummer heat relief is good for us, and it’s also a great time to do some of the cultural practices we often avoid during midsummer heat.

Creeping bentgrass and annual bluegrass don’t like the heat, and really don’t appreciate it when we implement certain cultural practices during hot weather.  On greens that have shallow roots and experience indirect heat stress, any kind of stress brought about with cultural practices can sometimes be the “straw that breaks the camel’s back.”  Consider implementing some of the following during short stretches of cool weather:

1) Solid tine aerification.  Opening up the surface of the green can help get oxygen to roots and prevent a “sealing off” of the surface that can arise when organic matter accumulates.

2) Verticutting.  Using vertical knives to cut leaves and stolons is certainly a stress to the plant, and now is a good time to do it if your greens are grainy (a la Johnny Miller!), or are accumulating more organic matter at the surface than desired.

3) Sand topdressing.  Topdressing during midsummer can be stressful to the plant especially if it the sand is dragged into the surface.

4) Product applications.  Some products can potentially cause more injury to creeping bentgrass and annual bluegrass when applied during hot weather, including liquid fertilizers, plant growth regulators, wetting agents, and even some fungicides.   Labels on some products specify temperatures in which they should be applied.  Use the break in the temperatures to apply products that may be needed.

5) Mowing and rolling.  If you haven’t done it yet, raise the mowing height if you can, and roll a few days each week instead of mowing.  Having more leaf area is always a good thing for the plant.

“Soil Evolution Par for the Golf Course”

Soil water management is a big topic on this blog. Are you curious about some of the science behind it?

How does water infiltration rate change as putting greens age? Big hint – it sure does not get BETTER over time.

This topic was featured in the recent edition of the news magazine of the CSA News (from the American Society of Agronomy/Crop Science Society of America/Soil Science Society of America). Here is the link to the article.

The article also talks about a weird iron layer that can build up over time.

Here is a key figure from the article, sourced from the USGA. Read the whole article to get the story. As you can see, older greens = slower infiltration:

Beware localized dry spot in putting greens – exacerbated by hot, dry winds

Summer is really here now, with fireflies, trips to the swimming pool, and … hot south winds to suck the moisture out of the ground. In sand-based putting greens, localized dry spot can pop up FAST, causing major damage in a short period of time.

Here is what localized dry spot can look like:

Keep an eye on your soil profile so you can stop this damage before it starts. When you get damage to the extent shown in those two photos above it is a long road to recovery.

To check for localized dry spot, pull up some cores and use the “droplet test” by putting drops of water on the plug. If the drops just sit there, not wicking in, you have a problem. The soil is water-repellent.

Sometimes there is a defined hydrophobic layer with normal soil above and/or below, so check at different depths, all the way down the rootzone:

You might also notice water beading up on the surface and not wicking in.

You don’t want this to sneak up on you. Keep an eye on your soil profile, especially locations with a history of problems. Aerification and use of wetting agents can help get moisture where it needs to go.

This example below shows how a slight change in the rootzone can cause problems. The round spots are all locations where the soil was altered for research, with little mini-plots inside tubes sunk into the ground. These spots are prone to LDS. We all know that putting greens are pretty sensitive, so be careful if you are changing up your sand topdressing or other soil-related factors.

A queasy feeling leading into summer – turfgrass root health

Got layers of organic matter in your putting greens? That stuff holds water, which holds heat, and serves as a “risk factor” for root health.

It’s another week with rain in the forecast in many parts of Kansas. We’ve talked about this before on the blog many times – root health is key to getting through our tough summer months.

Do you have drainage problems? Do you have a buildup of organic matter? How do your roots look now? Sites with “pre-existing conditions” are the first ones to crash when the weather gets nasty.

 

Moisture management can be tricky, but there are tips and tools to help you. Here are links to two articles from last year:

By Jack Fry: – general tips for water management:

https://blogs.k-state.edu/turf/good-water-management-will-help-get-greens-through-midsummer-stress/

By Dale Bremer – using moisture sensors:

https://blogs.k-state.edu/turf/water-management-on-greens-with-soil-moisture-sensors/

Reducing summer stress on putting greens:

I’ve mentioned this fungicide guide (below) many times over the years. One of my favorite parts is the section starting on page 6 about reducing summer stress. Quick, off the top of your head, how many practices can YOU think of to reduce summer stress? The guide lists SIXTEEN steps to consider. Maybe you can’t do them all, but I bet you can try at least one new thing you have not tried before.

Here is the link (scroll to p. 6 for the summer stress)
http://www2.ca.uky.edu/agcomm/pubs/ppa/ppa1/ppa1.pdf

Pythium root rot:

My excellent colleague at U of Missouri, Dr. Lee Miller, has recently posted some very helpful info about Pythium root rot. You can find those articles here:

http://turfpath.missouri.edu/reports/2017/update05_26_17.cfm

http://turfpath.missouri.edu/reports/2017/update05_11_17.cfm

Turfgrass Care for Homeowners on the K-State Radio Network

(By Jared Hoyle, KSU Turfgrass Research and Extension)

Just recently I was invited to speak with Eric Atkinson, host of Agriculture Today a daily program distributed to radio stations throughout the state. It features K-State agricultural specialists and other experts examining agricultural issues facing Kansas and the nation. I spoke with Eric about some issues that Kansas homeowners might be facing with their lawns and a couple things that homeowners shouldn’t worry about this year.

Click on the link below and hear more about;

  • possible winter injury
  • fertility
  • weed control
  • and more!

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

Can you tell the difference? – Little Barley Control for Homeowners

(By Jared Hoyle and Ward Upham; KSU Research and Extension)

 

slide1

 

Can you tell the difference?  There are two difference weeds in the picture above but they look a lot alike!  Not only do they look a lot alike but they both have similar attributes.  Below will tell you which one is which.

 

slide2

 

slide3

 

Many people mistake little barley (Hordeum pusillum) for a little foxtail because the foxtail and little barley seedheads are similar. However, little barley is a winter annual that comes up in late September – October and spends the winter as a small plant. It thrives in the cooler spring temperatures, forms seed heads and dies out usually by July. Foxtail, on the other hand, is a summer annual that does well in hot weather. Also, foxtail will not produce seedheads until mid- to late-summer.

 

slide4

 

So, why are we talking about little barley now? Because now is the time to control it for next year. The best control for little barley is a thick lawn that is mowed high enough that sunlight does not hit the soil. Little barley seed will not germinate in such conditions.  Overseeding now can thicken up a tall fescue lawn and prevent a little barley infestation.

However, if you do not plan to overseed, preemergence herbicides can be used to provide at least partial control of this weed. The only preemergence herbicide that I know is labeled specifically for little barley is Surflan. It is also sold under the name of Weed Impede by Monterey Lawn and Garden. Surflan can only be used on warm-season grasses (bermudagrass, buffalograss, zoysiagrass) and tall fescue grown in warm-season areas such as Kansas. However, Dimension (dithiopyr), is labeled for barley (Herodium spp.) which would include little barley and therefore
can be used to keep this weed under control. Because little barley is a winter annual, apply the preemergence herbicide now and water in to activate. If overseeding, do not apply any preemergence herbicide as it will interfere with the germination of tall fescue.

****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