I have a Fesue/Orchard grass field that is getting a growth of Johnson Grass in it. My neighbor just bailed it about 3 weeks ago.
Our farm and ranch supply sold me Outrider to spray on it. How tall do let it get before spraying it?
It's cooling off here in the Ozarks…. Was 47 this am but highs in the upper70's. Grass is still growing…. The JG in that field has regrown to about 6" or so.
What if we get a frost?
Thanks in advance.

Following to see results. Mine suggested Pastora and I sprayed a field that was 4-6 inches tall several weeks ago. Seems to have knocked it back, but we also have not had any recent rain.

The key is actively growing, and you have to have enough leaf surface to match the $&#@ rhizomes you're trying to kill. I would suspect somewhere between knee and waist tall should work. Is this a fairly new planting? If so, bailing and/or grazing might well do the trick. In perennial grass pastures, johnsongrass usually plays out with some minor harvest pressure and no disturbance.

It's an older field. Always been in really good shape. My neighbor and I have an agreement on bailing it.
He bales all over and I think he brought the damn JG seeds couple of years ago. Every year it has been spreading more.
I only bale it. No grazing.

Odd. I'll get flack over this, but in the world of perennial grasses, johnsongrass is a relatively weak sister. Spray who,e you can before frost.

Ive had customers get angry with me when I go to look at a hayfield for weed problems and recommend fertilizer and timely harvesting.

Gunny,

I know you're in a different local, so my experience in central Texas might not apply 100% to you.

Anyway, Pastora, while good, didn't do much on our johnsongrass.

This year, my guy sprayed Outrider (which is supposedly great for johnsongrass) but didn't follow the label instructions about the quantity and type of surfactant to use and as a result, we suppressed it, but didn't kill it. Basically, time and money wasted.

So, be sure and take care of the surfactant.

One more thing -- we're really dry in central Texas right now, and the johnsongrass is showing signs of heat stress, so I won't be doing any more spraying on it this year. Your johnsongrass might be growing fine and thus would be receptive to Outrider right now. I dunno.

Every time I think about how johnsongrass was intentionally introduced into this country I just shake my head.

A different approach. Johnson grass makes very good hay when fertilized & cut in the boot stage. . Fed it to my cows for many years.
Meadow was originally bluestem gordo. Johnson grass took it over.

Cows enjoy eating it so much they will graze it out and kill it in a pasture.

Thank you for the input sir. What type surfactant and how much?

Thank you. Appreciate the response and wonderful knowledge as usual.

Thank you everyone on responses. I am much obliged!

Gunny456 said:

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Thank you for the input sir. What type surfactant and how much?

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Gunny,

I went and pulled the label from the last batch of Outrider we bought:

Quote:

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Surfactants and Adjuvants

A nonionic surfactant is required for all postemergence applications of this product and is the only adjuvant required to be added to the spray solution.

Use only nonionic surfactants that contain at least 90 percent active ingredient. Add nonionic surfactants to a concentration of 0.25 to 0.5 percent by volume (1 to 2 quarts per 100 gallons of spray solution), unless otherwise directed.

Do not use low rates of liquid fertilizer as a substitute for surfactant.

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My guy put a 16 ounce bottle of cheap generic dish soap (not even Dawn) in a 1,000 gallon tank. See the problem?

FWIW, on stuff I mix and spray myself (mostly glyphosate plus imazapyr mix) , I've been using Alligare 90/10 surfactant with good results.

Muddyfeet said:

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Ive had customers get angry with me when I go to look at a hayfield for weed problems and recommend fertilizer and timely harvesting.

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i'm not sure many understand that a ungrazed hay field is just a nutrient mine. You are removing nutrients and taking them elsewhere.

that's why soil testing is so important, those nutrient imbalances can go sideways pretty quick.

I can't tell you how many times i hear, well i just have them put out same coop blend every year on my hayfields

Just what I needed. Thank you!

We soil sample every 2-3 years.

Gunny456 said:

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We soil sample every 2-3 years.

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i would up that to yearly on hay fields unless you got enough historic data to monitor those P and K levels and know about how much you're losing and replacing each year.

in your neck of the woods pH might not be a factor, in SE Texas is sure will impact the availability of those nutrients

There's a few options for Johnsongrass, but fewer in fescue. Where you are, you're probably going to get a killing frost within a month or so, so you may consider holding off. Outrider (sulfosulfuron) is probably all you'll be to use on fescue, but just know you'll have to tackle it again next spring. Hit it early before it tillers if possible, preferably 12" or smaller. Dont go above an oz/ac or your fescue wont like it. Also important to look at your water. Is it acidic? If so, product likely to underperform due to degradation. High pH is favorable to that chemistry. If only you had a chemical savvy Ag in state that could help you out…

And as stated before, use the right surfactant/ adjuvant.

Yes sir. Thank you for the response. Very good stuff.

BQ_90 said:

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Gunny456 said:

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We soil sample every 2-3 years.

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i would up that to yearly on hay fields unless you got enough historic data to monitor those P and K levels and know about how much you're losing and replacing each year.

in your neck of the woods pH might not be a factor, in SE Texas is sure will impact the availability of those nutrients

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This. Gunny did lime last year.

I didn't lime that field. It's bottom land and the soil sample report did not recommend it at that time.
This field is a problem child to me. It was taken care of really well by a man who leased it from the guy I bought it from for hay production. Mainly has fescue and orchard grass as I stated but has a bit of bluestem.
The guy who leased it died the year I bought it. My neighbor, who sold me some land when we moved here,
has cattle and always needs hay. He is a young man who inherited his farm and his wife has been battling cancer and they don't have much money.
So I was trying to be a good neighbor and offered him to be able and bale that field and take care of it. I asked for nothing except him taking care of the field.
Because he feeds cows he says he doesn't need to fertilize it. He won't spray it as he says he does not have the money.
It never had Johnson grass in it till I let him bale it.
So now I'm stuck. He is a good guy and wife and I love them as neighbors. I don't want my field to go to crap so guess I gotta spend the money to spray and fertilize.
Ok. I have vented. Thanks for reading my friend.

i would up to soil testing annually, if it's been hayed, esp multi cuttings and no fertilizer has been put back you might have some nutrient deficiencies.

i've not ever dealt with fescue/OG fields, but I did have a guy on some heavy clay soils in Grimes Co that was getting these johnsongrass spots in his hybrid bermuda fields. We actually just test those areas and nothing was wrong. I had my soil scientist come out and look. All we could figure it some soil micro issue where those sites where hold water enough to cause the bermuda to not grow and left enough sunlight for johnsongrass to grow.

We recommended IPT on those johnsongrass areas. Although my suggestion was to bail it all and rock on as normal. As long as you take caution, nothing wrong with a little johnsongrass in your hay

Thank you very much. Im dumb so what is IPT?
I would not worry with it but it is slowly taking over more and more of the field.
Makes good sense to have it soiled sampled. I will do that.

I really appreciate all of your guys inputs. More due that than just a thank you.

individual plant treatment, IE spot spraying instead of spraying entire field. I forget to not use acronyms.

Hay fields are pretty complex to manage. Like i posted before, if you never graze it, you're mining the soil of nutrients. weather, number of cuttings, etc will dictate how much and how fast those nutrients get removed.

that $20 soil sample is pretty cheap monitoring tool. Also without out you're guessing on if you're replacing the nutrients at the same rate as removal. Which isn't life or death, but normally weeds will find a gap and exploit it.

Also i'm a big fan of split applications during the year. I know the P and K will stick around, but the nitrogen will not, so dumping a whole season of fert in the beginning of the growing season will mean your nitrogen will be really lacking going into winter (for us in SE TX on Bermudagrass). Again I've never worked with anyone on fescue/OG.

BQ_90 said:

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i would up to soil testing annually, if it's been hayed, esp multi cuttings and no fertilizer has been put back you might have some nutrient deficiencies.

i've not ever dealt with fescue/OG fields, but I did have a guy on some heavy clay soils in Grimes Co that was getting these johnsongrass spots in his hybrid bermuda fields. We actually just test those areas and nothing was wrong. I had my soil scientist come out and look. All we could figure it some soil micro issue where those sites where hold water enough to cause the bermuda to not grow and left enough sunlight for johnsongrass to grow.

We recommended IPT on those johnsongrass areas. Although my suggestion was to bail it all and rock on as normal. As long as you take caution, nothing wrong with a little johnsongrass in your hay

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You think you're some kind of agronomist or something?

You nailed it. The best offense against weeds in a hay field is defense - good fertility, proper cutting height, and fertility. You're dealing with an introduced grass that want a little extra help to perform. Soil test, fertilize, get 2 cuttings next year and sell one.

Got it. Much obliged!

Sounds great to me. Thank you!

B-1 83 said:

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BQ_90 said:

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i would up to soil testing annually, if it's been hayed, esp multi cuttings and no fertilizer has been put back you might have some nutrient deficiencies.

i've not ever dealt with fescue/OG fields, but I did have a guy on some heavy clay soils in Grimes Co that was getting these johnsongrass spots in his hybrid bermuda fields. We actually just test those areas and nothing was wrong. I had my soil scientist come out and look. All we could figure it some soil micro issue where those sites where hold water enough to cause the bermuda to not grow and left enough sunlight for johnsongrass to grow.

We recommended IPT on those johnsongrass areas. Although my suggestion was to bail it all and rock on as normal. As long as you take caution, nothing wrong with a little johnsongrass in your hay

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You think you're some kind of agronomist or something?

You nailed it. The best offense against weeds in a hay field is defense - good fertility, proper cutting height, and fertility. You're dealing with an introduced grass that want a little extra help to perform. Soil test, fertilize, get 2 cuttings next year and sell one.

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i know enough to get in trouble. I understand the why's, but I don't understand all the chemistry involved in nutrients and the soil, not like you agros do.

But working 30+ years in high rainfall areas you learn how fast hay fields can deteriorate when nutrients aren't applied. I know in Louisiana on sandy ground, we had some dairy guys using anhydrous, hell i've seen pH down in the 3s. Talk about binding up nutrients.

My understanding is that Johnson Grass seed will remain in the soil for up to 2,000 years and just when you think you've eradicated it, it will spout, spread and repeat.

Courtesy Flush said:

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My understanding is that Johnson Grass seed will remain in the soil for up to 2,000 years and just when you think you've eradicated it, it will spout, spread and repeat.

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I don't know about that, I don't think it is known for hard seed content like Bahia grass or the Queen Mother of them all - field bindweed. I heard that Tech had done a study on field bindweed seed and stopped it after 20 years. Stuff still was viable and there was no point going further!

Courtesy Flush said:

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My understanding is that Johnson Grass seed will remain in the soil for up to 2,000 years and just when you think you've eradicated it, it will spout, spread and repeat.

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normally jg will not sprout and come up in a well managed hay field. I think what tends to happen is people cut late and scalp the ground. Well that doesn't leave enough recovery time before the grass grows dormant, so then weed seeds have a shot to get going since they tend to germinate before the warm season grasses get going the next spring.

B-1 has hit on it, proper cutting height is just as important as fertility management.