Johnson grass

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The issue people around here have with it is the way it takes over in patches. Then you have this dilemma where the JG is ready to be cut and none of the other grass is. Not enough to cut on it’s own but leave it alone and you got patches of tall, rank JG that isn’t worth cutting and will absolutely kill out other grass.

The other issue here is with drying. When the conditions are right and the whole field (JG and other grass) is worth cutting you have everything else ready to go and JG needs more time to dry, whether you have the time or not.

I have went out and found all the other grass and the JG leaves dry and ready to bale but the stems still are pretty wet. The baling windows are often short so it gets baled anyways and well we know what that bale will be. Not always totally ruined but not the greatest either. I have heard a moco helps with the stems but if you don’t have one already you likely aren’t going to purchase one for this.

If seems that JG would be really good if you had a solid stand of it and you have either the ideal drying conditions and/or something to speed it along. Neither of those things happen often here so the question becomes is the juice worth the squeeze. Probably not.

As far as grazing it, I welcome it and have no issues with it.

If the Outrider works in fescue (which I’m reading it does in established stands), it would be cheaper for me going that route over buying a weed wiper even though it is PRICY. One would have to figure the math out for themselves on that though.
 
kenny thomas said:
It gets big and rank and is a problem cutting, raking, and rolling it. Plus they wont eat it when its mature.
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Been hayin Jgrass 20+ years, that's the only problem I ever had if I didn't cut it 3 times !
Once I played with the idea of buyin a hay roller with a chopper, price of roller wasn't real bad, but a new tractor with 40+ more HP was very Bad!
 
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Kenny Thomas, I used Outrider on my Johnson Grass in the hay field. I used to rope wick it, which works great, but had to go both ways as it was so thick in places as you go over it; bends over and don't get all the leaves wiped. So I had to go make a U turn and come right back in the same tracks. It just took such a long time to get it done. So s-l-o-w!!

This past year I used Outrider. It is expensive but it was well worth it. Each time I use a product and mix it, write down the results so I won't try to remember exactly how it worked. So this is what I recorded last year.
Outrider- 2oz to the acre and it comes in a 20 oz bottle as it was just right for the 10 acre field of Bermuda I sprayed it on. I have a 200 gallon tank so I mixed 10 gallons of Class Act as it has ammonium sulfate which puts the JG into a spurt of growth allowing the herbicide to work better. Seems when plants are in a growing situation, they as it abosorbs better on new growth.
Also added to the 200 gallons, 8 pints of nonionic surfactant and 2 quarts of drift agent as I am surrounded by crops on three sides and cannot let the spray move to beans, corn, or cotton.

Also, Outrider totally kills nutsedge grass. When you first spray Outrider, it is a slow kill, but you will see that the JG nor the Nut Sedge grows any taller nor does it spread for the first few days. Then the sheen is gone from the leaves, and the JG will begin to show a dark purple leaf in the group then more will develop about 2 leaves per clump. The purple is a sign it is on the way out. Then the JG pretty much stays green for the most, but it becomes dehydrated and falls sideways if it is not really tall. It is totally dead.

On the Nutsedge, it is even slower. At first you think it is not going to die. But it is not growing at all. Slowly, it changes to a duller leaf and then slowly it turns yellow until it is gone. I kept looking at it thinking it looked sickly but was afraid it might get a second wind and pull out of it. No way.
Outrider the chemical name is Sulfosulfuran 75%. They may have a generic brand of this now, but not sure.
Just looked it up today May 28, 2026 and the price for a 20 oz jar of it is $354.99 on Chemical Warehouse for reference. The reason I added so much extra to this herbicide was because it was so expensive that I did not want to take a chance on it doing a half azz job, so go ahead and do it right. Too, the drift factor, but little wind was blowing, less than 5 mph.

I called the people that make Outrider and told them it was by far the most effective herbicide I have ever used and told them how much I used. For some reason, I had a question, but at this time I cannot remember. But he said that there might be a chance that a leaf or two may emerge in the field. But if it does, he said that I would not have to use as strong of a solution as I did. Which was 2 oz per acre. He said cut it back and it will kill it. It shows on the bottle to use .66 oz to 2.0 ounces to the acre. I spot sprayed it with a hand sprayer as just a few emerged in a field that was probably 2/3 covered by some form of Johnson Grass. Not a total stand like wheat, but if I had not of sprayed it, by the end of the summer, it pretty much would be solid.

I had probably two very small clumps to come back with about 3 or 4 leaves and that was it.
It was so well worth the cost as my field was starting to be taken over after a few years of neglect.

When I sprayed, to get the right amount of the herbicide down to make it work correctly, I did 200 gallons of spray running 5 mph, at 30 psi.

Worked like a dream. Sorry I did not write about it before. I think I wrote about it on a hay forum as someone asked there and thought I had responded here.

Hope that knee is doing well. I know that it does not hurt near as bad as it did before you did surgery, but it will just keep on getting better.
 
I have looked up Johnson Grass as hay, and if you can stay on top of it, which will be every 28 days or before it develops a woody stem, the cattle eat it like candy. They love it. Before, the rain came too often to be able to catch it before it ever started a seed head. At that point, the cattle will not eat it as it is too tough and just pull it out of the hay rings.

Look it up and if you fertilize it, the nutrition level is as good as any grass hay you can feed and often higher. But the word Johnson Grass in my area which is row crops, people spazz out thinking you are growing Johnson Grass.

I read an article about Johnson Grass hay that is fertilized and cut every 28 days, and said people with show cattle would grab it if they knew you had taken care of the field. Must be because they eat so much of it and it is sweet. Seems people don't fertilize it because it grows fast. But enough nitrogen can replace a lot of protein provided by feed. And probably don't have to spray for army worms and often extra work on other hay crops.
I added a hay comparison chart to show the value of JG as hay alone.

Read where it shows that the prussic acid only pertains to the plant that is alive. After cutting for hay and dries out, that problem no longer exits. Added an article for those that still worry it exists in the dry hay. I see in this article that there is another herbicide of the same chemical as Outrider called, "Maverick." But made by the same company as Valent but it is considered a corn herbicide. Seems the mix rate is different so there may be a different formulation than for hay.


https://www.aces.edu/blog/topics/farming/johnsongrass-frequently-asked-questions/

I know I have it in my pasture as when I pull animals out of that field it barely shows up as they keep the energy levels low in the stolens and doesn't have the nutrients to come back so strong.
Here is a chart of grasses of crude protein. Wish they listed how much NPK they put down per acre. And too, soils are different, But gives you a good idea.
0911pc_bates_tb_1_full.jpg
 
Well, sorry, I did post it here.
Chuckie

Thread 'Outrider Herbicide Mixture'

I am going to spray Outrider tomorrow morning as that is when the wind will be below 5 mph. I want to mix a non ionic surfactant with it and a drift control. Anyone ever added Class Act with this herbicide as well. It is supposed to smoke Johnson Grass and Nutsedge and not harm Bermuda grass. If this works the way they say it does, then I will be so very happy.

Trying to get this Bermuda Grass hay field back in shape. It was let go for a few years and the Bermuda is still out there, but so is the Johnson Grass, Nutsedge, Indian Hemp, and Orange trumpet vine which is sold in flower...
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kenny thomas said:
I know a lot has been discussed in the past about the good and bad of Johnson grass. I like it in pastfure but not in the hay because its not ready at the same time as the other grasses.
For those that have dealt with it, what can be sprayed to kill johnson grass but not the native grasses?
Yes im going to ask my extension agent also.
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Wickbar with Roundup full strength. I think in a lot of areas they call it a weed wiper. I use it when the JG is about a foot taller than the Bermuda. If it ever quits raining I am going to use it on a formerly great Bermuda field that I let someone else rent last year. I have waged a 50 year war on JG and crabgrass in my Bermuda horse-hay fields.
 
@Warren Allison, if you can find anything that works on crabgrass that can be grazed or be sprayed on hay ground, share it with us. I have found chemicals I can spray for yards, but not for food source for cattle or horses. In the pasture, they love the crab grass second to the clover. But not good as hay. Good luck with your war on all the things that don't belong!!
 
blackladies said:
Why worry about it then?
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@blackladies, it comes down to what your goals and objectives (what you want to do or what you are doing, or what you are trying to do. A very few plants in number mat be a problem as those few end up contaminating all the good hay. If that isn't the case, just having those few, if not immediately acted upon (of worried about) can end up as 70% or more of the entire field and render it unusable. On the other hand, if it is something you want to have and you just find a few, you will want to protect them and encourage their spread. Having only a few of anything has the potential to be a huge game changer. Having 'a few' is often much more significant than having many or a lot, as an indicator of what is yet to come. The 'few' are indicators that are trying to tell you something. You need to listen.
 
Turned the cows into the 20 acres on Monday. They stripped the JG clean of leaves in 4 days before starting on grass. Ordering my weed wiper today but decided to brush hog the stalks out. Rye grass has turned and falling so I got that out of the way so bermuda and crab grass can get more sun. Hope to get another week on this patch before moving and that should allow me to wipe and control the JG for next grazing in Sept time frame
 
I absolutely love JG. This has had about 10 to 15 days since being grazed off, super dry until a week or so ago. It does become a problem towards August or September, but all I do is clip behind the cows. If I dont i have eye problems due to the stems.
 

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JG started filling in when I started doing no till planting Milo. I would round up the field and plant right behind it. Jg,crab grass and stickers came galore. I went to cool season grasses and was able to help a little but was losing the war in summer. This place had little grass except bermuda/weeds when we got it but 45 acres had always been in agriculture with what we always called trash farming. Growing up in Kansas in the 60's everyone had 4-6 bottom plows. With retirement right around the corner at that time I didn't want to dump money in iron, pencil just wouldn't make it work. An older farmer I always bounced ideas off of offered me an old haybuster no till that needed a lot of work. Three stipulations were it didn't come back unless asked for, I didn't loan it out, and I keep maintenance up once I got it running. Joined this site, drovers, progressive farming and studied all the tube I could find on rotational grazing. I'm happy with progress but just don't want this JG to worry about. Hope the weed wrecker does the trick! Man that was wordy🤣
 
You are over worrying the situation. The Johnson grass is going to be in our area no matter what. I have planted it or its cousin sorghum almum a number of times when seed was more readily available. Sorghum Almum is a better grass with tender stalks and more leaf. Both provide a lot of forage on marginal land. The do great on creek bottom land. They both need to be managed if conditions are where it can be dangerous. I have it in a lot of pastures that the cows rotate through. They love it so a stand does not last long if its over grazed.

Anytime you disturb the soil, you will bring up a bunch of JG seeds along with weeds. Your fighting mother nature trying to get rid of it. You can win but is the fight really worth it?
 
How do you guys grazing Johnson grass keep it from killing your cattle? We have allot of johnson grass in the ditches and have been having some odd weather lately. Lots of rain and overcast days. Young calves have been sticking their head through the fence to eat it and we've found 2 dead so far. Might not be johnson grass but they seemed healthy then dead.
 
Lucky said:
How do you guys grazing Johnson grass keep it from killing your cattle? We have allot of johnson grass in the ditches and have been having some odd weather lately. Lots of rain and overcast days. Young calves have been sticking their head through the fence to eat it and we've found 2 dead so far. Might not be johnson grass but they seemed healthy then dead.
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@Lucky, how hot is it? Unless it's really hot, Johnson grass shouldn't be the problem. Also, that should only be in drought stress as well. Here's a weird thought: Grass tetany in the calves due to the Johnson grass? That would be the first I've ever heard of that. However, the healthy and then suddenly dead is a classic symptom of grass tetany. How are your magnesium levels in your soil tests? My thought here is a WAG, but if the calves only can reach the Johnson grass, and for whatever reason it is the fastest growing thing out there right now (unusually fast), and you soil is low on magnesium, the stars are aligned to deliver the symptoms you just described. If a possible cause, an injection from the vet solves the acute symptoms in under 15 minutes. Put out a high mag mineral supplement immediately or give all the calves a bolus with magnesium (check with a vet though).
 
Lucky said:
How do you guys grazing Johnson grass keep it from killing your cattle? We have allot of johnson grass in the ditches and have been having some odd weather lately. Lots of rain and overcast days. Young calves have been sticking their head through the fence to eat it and we've found 2 dead so far. Might not be johnson grass but they seemed healthy then dead.
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I ordered a role of test strip to test the cyanide before I turned out. Also talked to cattlemen and got same answers as bird dog has (thank you)! July/August/September seems to be the bad months in our parts per our local county agent. He also advised waiting a week after any rain
 
Mark Reynolds said:
@Lucky, how hot is it? Unless it's really hot, Johnson grass shouldn't be the problem. Also, that should only be in drought stress as well. Here's a weird thought: Grass tetany in the calves due to the Johnson grass? That would be the first I've ever heard of that. However, the healthy and then suddenly dead is a classic symptom of grass tetany. How are your magnesium levels in your soil tests? My thought here is a WAG, but if the calves only can reach the Johnson grass, and for whatever reason it is the fastest growing thing out there right now (unusually fast), and you soil is low on magnesium, the stars are aligned to deliver the symptoms you just described. If a possible cause, an injection from the vet solves the acute symptoms in under 15 minutes. Put out a high mag mineral supplement immediately or give all the calves a bolus with magnesium (check with a vet though).
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Temps have been in the low 80's to low 90's overcast weather with a little to allot rain everyday. I turned the cows in this pasture knowing the johnson grass was there but I'd mowed along the road a week before. I've got High Mag mineral tubs out and they seem to be eating them pretty good. The calves stick their head through the fence and eat the JG but I wasn't worried about it because it shouldn't be stressed. Lost 2 200# bull calves so far. We moved them yesterday after finding the 2nd one.

We also worked all the calves on May 18th so hoping it's not tetanus. We lost the 1st one on the 20th so kinda ruled that out though. First trouble we've had like this. I think it's a stretch but the JG being short and tender is all I can figure.
 
Mark Reynolds said:
@Lucky, how hot is it? Unless it's really hot, Johnson grass shouldn't be the problem. Also, that should only be in drought stress as well. Here's a weird thought: Grass tetany in the calves due to the Johnson grass? That would be the first I've ever heard of that. However, the healthy and then suddenly dead is a classic symptom of grass tetany. How are your magnesium levels in your soil tests? My thought here is a WAG, but if the calves only can reach the Johnson grass, and for whatever reason it is the fastest growing thing out there right now (unusually fast), and you soil is low on magnesium, the stars are aligned to deliver the symptoms you just described. If a possible cause, an injection from the vet solves the acute symptoms in under 15 minutes. Put out a high mag mineral supplement immediately or give all the calves a bolus with magnesium (check with a vet though).
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200lb calves do not get grass tetney. Only cows with smaller calves when their magnesium gets low after calving and the grass is still weak in the spring.
 

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