Kansas State University


K-State Turf and Landscape Blog

Month: May 2017

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:


By Dale Bremer – using 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)

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:



Rose sawflies

There have been numerous inquiries regarding insects feeding, and completely devouring rose plants. These are sawflies, and there are at least two species that attack roses this time of year: the rose slug (Endelomyia aethiops) and bristly rose slug (Cladius difformis). Rose slugs are the immature or larval stage of sawflies, which are black to yellow-colored wasps.

Get the whole story on the Entomology Blog

(Photo by Raymond Cloyd)

How to plant trees the right way!

Here in the K-State Diagnostic lab we deal with trees that are planted WRONG all the time! When trees are planted wrong, they start out extra stressed from day one. Trees are stressed enough just trying to live in our crazy Kansas weather, so, how do you plant them RIGHT?

Check out this easy-to-use guide from Dr. Cathie Lavis:


There is a one-page guide to ball-in-burlap and a one page guide to container-grown trees.

Here’s one thing we don’t want, a big ol’ girdling root! And below that I put some photos I took of a display about planting trees wrong – you can click to zoom in a bit and check it out.

Powdery mildew in turf

Turf powdery mildew thrives in shady sites during cool, humid weather. We have had a lot of cool, moist days with temps in the 50s and 60s which is perfect for powdery mildew. The disease is often temporary, disappearing when hotter, drier weather kicks in.

The following photos are courtesy of my excellent colleague Chuck Otte, County Extension Agent, Ag & Natural Resources, Geary County. He confirmed that the site is shady.

It’s a fescue/bluegrass blend. To my eye, it looks like the Kentucky bluegrass is affected more than the fescue.

This next photo is a super-zoom of powdery mildew through the microscope. The photo is from squash powdery mildew, not turf powdery mildew, but turf powdery produces similar structures – long chains of spores. The spores are blown by wind. When they land on a new, susceptible plant and IF conditions are right, they germinate and infect.

We see turf powdery mildew in spring and fall. A change to less humid, hotter weather will slow the disease.

Turf powdery mildew is one of the many diseases covered in the 2017 Turfgrass Fungicide Guide.

There are fungicides labeled, but for most of them little is known about the efficacy. The DMI fungicides have efficacy, but it can be hard to reduce disease once it is underway. Also, as I just mentioned, a shift in the weather will slow the disease. If a site has a chronic, ongoing powdery mildew options include improving airflow and sun exposure or renovating to a less susceptible type of turf or groundcover. Those cultural practices and site management tweaks are your best bet.

“In the event of a pesticide spill, follow the three Cs: CONTROL the spill, CONTAIN it, and CLEAN it up.”

Do you have a plan in place in case of a pesticide spill? You don’t want to be inventing your plan on the fly, in the moment.

Here at KSU in our research labs we go through “spill drills” each year to make sure we are ready, just in case. It’s not our favorite thing to do, but it means everyone knows what to do, just like a fire drill.

Here are some tips on pesticide spill procedures from U of Kentucky:

Dealing with Pesticide Spills

Emerald Ash Borer Workshop – Doniphan County, June 7

The Kansas Forest Service is sponsoring a workshop about EAB on June 7, 12:30-4:30 in Troy (Doniphan County). Topics include identification and biology, EAB quarantine rules, tree injection information, and more. Certified pesticide applicator and arborist credits are available.

Here is the link to the brochure:



There is a shorter, more general session in the evening:

Tree Field Day, Overland Park Arboretum, June 2

The Kansas Forest Service is hosting a tree event at the Overland Park Arboretum on Friday, June 2. It’s the Walnut Council Field Day, and usually the focus is more on rural trees. But, with the unique Overland Park location, some of the topics are right in line with urban trees, including tree identification and tree problems

Here is the registration form and full schedule:


Plants are good for people

I think we all know that plants and nature are good for people. However, to read more about the social side of the green industry you can check out this interesting article about “Trees, jobs, health, and equity in the urban forest.”

As the article says, “Even the smallest bits of nature in the city can make a positive difference in people’s daily lives.”

Here is the link:


Anthracnose in shade trees

Here is a quick update from Ward Upham and the Horticulture News:

We are starting to see anthracnose on sycamore. Anthracnose is a fungal disease favored by cool, wet weather. Young leaves may wither and turn black. On older leaves, look for brown areas that follow the major veins of the leaves. In some cases, the petiole (leaf stem) is infected, which causes leaf drop. The leaf may look perfectly fine, so look for browned areas on the petiole.
In severe cases, the tree drops heavily infected leaves and may be completely defoliated. Healthy trees will leaf out again in a few weeks. Defoliation this early in the year does not affect overall tree health. Trees have plenty of time to produce new leaves and make the energy reserves needed to survive the winter.
Other types of trees that are affected by anthracnose include birch, elm, walnut, oak and especially ash. Anthracnose seldom causes significant damage to trees in Kansas, so chemical controls are usually unnecessary. Also, fungicides do not cure infected leaves. Applying fungicides now will not help.


For a detailed overview of anthracnose diseases of shade trees, you can check out the free online pdf version of Diseases of Trees in the Great Plains. I’ve mentioned this book before – it is a great resource!  Here is the link, and the anthracnose part is the section section, on p. 22 of the pdf.

Anthracnose is also covered in our Tree and Shrub Problems of Kansas book.