(By Jared Hoyle, KSU Turfgrass Research and Extension)
The 70 MPH weed…. That is what I call yellow nutsedge. Why? It’s because you can be driving 70 MPH down the highway, look over, and see yellow nutsedge growing in a lawn. The erect light green linear leaves tend to grow faster than the turf so it sticks up above the canopy.
Yellow nutsedge can not only grow in wet soils but also extremely dry soils as well.
Yellow nutsedge is not a new weed but it sure is a persistent weed. In Kansas, typically we don’t see it until about June.
Once 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!
For homeowners – Here is some more information to help with yellow nutsedge control in a home lawn.
****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.***
The next Turfgrass Field Day will be held on Thursday, August 3, 2017 at the John C. Pair Horticultural Research Center, Wichita. The KTF Turf Field Days are a great way to see and learn about the turfgrass research at K-State first hand. The events are held annually in the summer at the turfgrass research locations of Kansas State University.
The Field Day qualifies for recertification credit hr for commercial pesticide applicators.
You can now Register and Pay Online athttps://2017turffieldday.eventbrite.com or you can register by downloading, printing, and mailing go to the 2017 Field Day brochure.
Schedule of the 2017 Field Day
8:00 a.m. Registration (coffee, tea, donuts)
Visit Exhibitors
8:45 Welcome
9:00 Tour Highlights:
*Turfgrass Weed Control Update
*Turf & Ornamental Diseases
*Bermudagrass & Zoysiagrass Cultivar Selection
*Using Kansas Mesonet to Imrpove Accuracy in Landscape Irrigation
*Right Plant, FROM the Right Place
* Prairie Star Flowers
*Tall Fescue NTEP
*Turf & Ornamental Insect Control 11:30 Lunch
After Lunch
Equipment Demonstrations
If you have any questions, please contact, Christy Dipman 1712 Claflin, 2021 Throckmorton Hall
Manhattan, Kansas 66506
Phone: (785) 532-6173
Fax: (785) 532-6949
Email: Christy
(By Jared Hoyle, KSU Turfgrass Research and Extension)
Many people like the smell of freshly cut grass but there is a weed out there that is common in many lawns in KS called stinkgrass and it stinks. It stinks cause it is a weed and it also literally stinks.
Stinkgrass sometimes referred to as stinking lovegrass or candy grass is a summer annual grassy weed that was introduced from Europe. This weed is most noticeable when the grayish-green triangular shaped panicle type seedhead is present. The seedhead closely resembles that of the bluegrass family and may cause confusion in identification. Individual spikelets, however, possess a grayish-silver, sometimes purple color and at times may appear waxy.
The leaves are smooth, glossy below and rough on top typically ranging from ¼ to ½ inch wide. The stem of the plant is jointed with slightly swollen nodes, occasionally with a 45 degree bend near the stem base.To vegetatively identify stinkgrass, look at the ligule, the sheath and back of the leaf blade where it attaches to the collar. The ligule is a short fringe of hairs, with several long hairs at the outer edge.
Another distinctive characteristic of stinkgrass is that it produces a bitter pungent odor, most noticeable when the tissue is crushed or mowed, hence the name stinkgrass. It is said to be poisonous to livestock, particularly horses, but most animals avoid grazing it because of the odor. Stinkgrass normally spreads by seed dispersal which emerges in late spring a few weeks after crabgrass or at a similar time to goosegrass. Maximum germination occurs when soil temperatures remain above 65°F for several weeks. Mature this plant will grow from 1 to 2 feet tall and it can temporarily survive mowing heights typical for home-lawns.
Occurrence
In general, stinkgrass is not a persistent problem in lawns but commonly occurs in newly established or poorly maintained lawns and low maintenance areas like roadsides that were once cultivated as agricultural land. It can also be a problem in newly planted sod fields. It has a shallow fibrous root system and is normally not a problem in properly maintained turf the second year after planting.
Non-Chemical Control
Stinkgrass can be very easily removed by hand. In newly established lawns, however, practices to promote maximum density of the desirable turf species like adequate fertility, proper mowing and irrigation will eventually crowd out this weed. Stinkgrass will die after the first killing autumn frost allowing a vigorous desirable turf species to fill the voids.
No specific pre-emergence herbicides are labeled for turf use, though most common pre-emergent herbicides suitable for crabgrass and goosegrass should also be effective on stinkgrass without injury to the desired turf species. The only compounds labeled for post-emergent control are glufosinate (Finale) or glyphosate (Round-up). Both of these herbicides are non-selective herbicides which kill all green plants and should not be applied to desirable turfgrasses. Once the stinkgrass has been controlled, however, these areas can then be reseeded or sodded.
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.***
(By Jared Hoyle, KSU Turfgrass Research and Extension)
This past weekend I was at a lawn and garden store and saw the Roundup for Lawns display. Customers were walking by and picking up a bottle. Some would get Roundup MAXX, Roundup for Lawns and some bought just straight Roundup. I thought to myself, “I hope they know the different between those products.”
Here is some information on the products and a link to Agriculture Today, daily radio program, with Eric Atkinson and Dr. Jared Hoyle. He explains the difference between the products and even what the bottles look like and why it is important to make sure you pick up the correct product.
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.***
(By Jared Hoyle, KSU Turfgrass Research and Extension)
About a week ago I was invited back again 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.
This week we covered the following;
fertilization of cool-season lawns
fertilization of warm-season lawns
weed control
preemergent herbicide control
spring mowing heights
Check out the radio program below!
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.***
(By Jared Hoyle and Ward Upham, KSU Research and Extension)
When we talk about cool-season turfgrass seeding timing I always think the fall. Well all around town I keep seeing more and more people seeding their lawn this spring. I don’t want to say you are wasting your time because there are a couple reasons that you might need or have to seed in the spring but most success is achieved if seeding cool-season turfgrass in the fall.
There are several reasons Kentucky bluegrass and tall fescue lawns are better seeded in the fall than in the spring.
These include:
Some of the most serious lawn weeds such as crabgrass and foxtail emerge in the spring. Since they are warm-season weeds, they will compete and often crowd out young, tender cool-season grasses during the heat of summer.
The most stressful time of year for cool-season grasses is summer, not winter. Poorly established lawns may die out during the summer due to heat and drought stress.
A lawn often gets more use during the summer, leading to increased compaction and traffic stress. Young plants have a hard time surviving the high traffic during the summer.
Weed competition when establishing cool-season from seed in the spring.
If an area needs to be established in the spring, sodding is much more likely to be successful than seeding. Sodding provides stronger, more mature plants that are better able to withstand stress and prevent weed invasion.
(By Jared Hoyle, KSU Turfgrass Research and Extension)
The other day after eating dinner I was watching TV trying to finally relax. A commercial came on about Roundup for lawns…. I thought to myself “Oh man, This is going to cause a lot of confusion!”
There is a huge difference in the active ingredients in Roundup compared to Roundup for Lawns. That is why it is so important to know what you are applying.
Dr. Kevin Frank at Michigan State University just posted a great article about the difference between Roundup and Roundup for Lawns. Check it out here.
I will make a prediction. Due to the confusion with the names of these products. I will get at least one phone call this year where someone has killed their entire lawn with glyphosate because they thought they could use Roundup on their lawn and they put out the wrong product.
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.***
(By Jared Hoyle, KSU Turfgrass Research and Extension)
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 consume.
Wild garlic is more obvious in the winter and early spring because this weed will grow above the turfgrass canopy and is easily noticed. 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 (Right now!) on a warm day above 50 deg F (Right now!) when there is good soil moisture (Right now!) 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.***
(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!!!
***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.***
(By Jared Hoyle, KSU Turfgrass Research and Extension)
This morning when I cranked my truck up and headed to the office it was 25 deg F. Just a couple days ago it snowed. Just before that it was 80 deg F. What is going on with the weather? (Every time I make that statement, someone says “Welcome to Kansas!”) With the fluctuating weather and temperatures I get the question “What date do I need to put my preemerge herbicide out on?”
Well this is a trick question because there is no correct answer for it. Here are some of my thoughts on preemerge timing.
As soon as that first warm front comes through everyone gets excited and ready to work in their lawn. I have even heard the comment that spring and summer are going to come early this year. Are they right? I don’t know but it is something to think about.
But as soon as we get excited about the warm weather we have another cold snap. So we got all excited and talked about weeds germinating early and needing to get out our preemergence herbicides because the forsythias are blooming. But what happens when it gets cold? Any crabgrass that “might” have germinated is now dead because of the cold temperatures. So this brings up a lot of discussion between myself and some colleges. Here are just some of the questions we are asked and a couple of comments.
Why do we recommend around April 15th for most of Kansas to put out a preemerge in our lawns?
– April 15th is about the time that we have our “last” frost/freeze. (This also shifts to April 30th in Western/North Western KS and to April 1 in Eastern/South Eastern KS.) This goes along with our concept that I was talking about before. Even though it may be getting warm we are still might have a cold snap that would end up killing the crabgrass if it emerged. This is the same concept of why we don’t plant crops until after this date as well. (Something I don’t know anything about but that is what I figure…..)
Should we use soil temperature at 1″ to predict when to put out preemergent herbicide applications?
-Soil temperatures are a great way of determining when to apply your preemerge herbicide. Scientists say when soils reach a daily average of 55 deg F for about 5 days at a 1″ soil depth then it is time to put out your preemerge. Well say you go out and measure your soil temperature at 1″ you are not going to get a daily average, you are getting a single point in time. Does that really represent what is going on? What if you are maintaining many different properties. It is not practical to obtain that information. Good news is that KSU has a website (http://mesonet.k-state.edu) that you can click your closest weather station and get daily maximum and minimum soil temperatures where you can then calculate a daily average. Bad news it only give you a 2″ or a 4″ soil temperature. But using the 2″ soil temperatures are going to give you a better idea of the daily averages then going and taking one measurement.
The forsythias are blooming but my redbuds aren’t. Do I still put my preemergent herbicide out?
– This is called phenology – the study of cyclic and seasonal natural phenomena, especially in relationship to climate, plant and animal life. Many people believe that when the forsythias are blooming then crabgrass is germinating. That is not 100% true. When forsythias are in full bloom then we need to be getting “ready” to get our preemerge applied. Even though we see that this is a good indicator, Dr. Fry and others reported in a study that ornamental plant flowering is not always a good way to predict crabgrass germination and emergence. (Fry, J., S. Rodie, R. Gaussoin, S. Wiest, W. Upham, and A.Zuk. 2001. Using flowering ornamentals to guide application of preemergence herbicides in the Midwestern U.S. International Turfgrass Soc. Res. J. 9:1009-1012.) There are some things to consider when utilizing phenology for crabgrass germination and emergence. Not all forsythias will bloom at the same time. It determines where that plant is located in the landscape. There are micro climates in the landscape. Think about plants located in roadway medians. They are typically warmer due to cars and the concrete and asphalt in close proximity. The same thing goes with crabgrass germination. Crabgrass will germinated sooner in areas that are warmer, for example (next to sidewalks, bare ground, etc.).
Crabgrass emerging in bare ground earlier than turf
I have heard about growing degree days to predict crabgrass germination. What is that?
– Growing degree days (GDD) use air temperatures instead of soil temperatures within a formula to get a cumulative number of growing degree days. Using base 50 deg F, once you get to about 200 GDD then crabgrass will start to germinate. Don’t want to calculate GDDs, don’t worry there is a website that will do it for you. http://www.gddtracker.net Just enter your area code and click on crabgrass germination on the right side and it will give you the total GDD. It will also show you a prediction for the next couple of days too. GDD do not go backwards, they only accumulate.
So to put this all in perspective using the prediction methods mentioned above this is what we got;
Today is March 14th so using the calendar model for Manhattan we would not put our preemerge out until closer to April 15th for Manhattan.
Using the 2″ soil temperature method because that is what is available to us our daily average soil temperatures (Deg F) have been;
9-Mar
47.6
10-Mar
45.4
11-Mar
43.65
12-Mar
41.15
13-Mar
39.65
With this method we would assume the 1″ soil temperature is higher but we are not to the 55 deg F mark yet. So we are getting close to putting out our preemerge herbicide.
In my back yard my forsythias are blooming. So that means if I am using the phenology method I need to be getting ready to apply my preemergence.
Lastly, using the GDD model we are at 85 GDD. So I still have some time but getting close. Remember though that you can get more than one GGD in one calendar day and if I look at the future (prediction on the GDD Tracker website) on March 20th Manhattan will be at 111 GDD. So just in 6 days we would have gained 26 GDD.
Now these rules, concepts, ideas are not bullet proof but it is something to think about when planning your lawn care program. There is not magic date for anything that you do to you lawn. You need to make sure you keep up with the temperatures, soil temperatures, precipitation, etc. The more you know what is going on with your turfgrass the better you will be able to predict crabgrass preemergent applications. Use more than one method. This is going to give you the best idea of what to do!
Now by this weekend we are going to get a little warmer but again looking at the 10 day forecast it might get cold again…. Just something to think about. I hope this got you thinking as a turfgrass manager and how this is going to help you choose products if you are going to have to get applications out earlier or even later after crabgrass has emerged.
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.***
