At our new farm in TN we have about 25 acres of pasture and hay field (about 5 currently fenced for the horses and planning to fence off another 5 of the hay field soon for pasture). I noticed that the horses were not very interested in eating some fast growing, stemmy grass that covers maybe 1/4 of our land and starting asking around about it. Turns out it is Johnson grass which apparently is very invasive (considered a weed) and I’m told it can have cyanide in it during certain weather conditions like drought or after frost. So if you have experience and/or suggestions for trying to eradicate it, please HELP!!! Thanks!
mow the snot out of it.
When you figure it out, I know a few hay suppliers around here who will want to know how you did it!:lol:
Before pricing themselves out of our budget, we bought hay from one of the top producing hay growers here in GA. They started having serious problems with Johnson grass and consulted the Univ. of GA on how to eradicate it. They were given several suggestions - one was to mow it down and treat religiously with professional grade Round-Up. Another suggestion was to burn it off. They tried all that plus a few other ideas given to them. I drove by their hay fields a few weeks ago and noticed they still have big clumps of Johnson Grass out there.
Burning it off worked great on my old farm, but I can’t do that here. We just try to keep it mowed. Don’t worry too much about the horses eating it- it’s not very palatable.
Mine like it when it’s small, so mowing works well. When it gets to look like small cornstalks is when it’s bad news (but they have to eat quite a bit of it, and it isn’t very palatable).
Now, Pigweed is another story - I’m at my wit’s end with the stuff!
Pigweed–see if you have what is called Palmer Pigweed. It’s become a super weed that is resistant to Round Up and is causing heartache here for row crop farmers. Each plant produces more than a million seeds, and they are able to grow on almost any soil, no matter how infertile. It is edible, and my horses will sometimes eat it in preference to hay. It’s actually a kind of amaranth, which in another form is edible for humans.
Best thing for pigweed is 2,4-D, but that chemical doesn’t like temperatures over 90.
Or you could get some pigs turned out on it. They love it. That’s why it’s called pigweed. 
If you can keep horses off the pasture for a few months, MSMA (has arsenic) will burn Johnson grass back and keep it under control. However, my horses love the stuff, since it is lush even in tremendous heat and lack of rain.
That’s odd, because I could have sworn an old barn of mine fed Johnson grass hay?? And the horses loved it.
Ahhh Johnson grass and pigweed — the arch nemesis in my pastures with stinging nettle not far behind, and the white sage can do a decent job of taking over if it’s not kept bushhogged down.
I have read the only way to truly eradicate pigweed is to hand pull every piece of root out. That might work on someone’s suburbia lawn but it’s a ridiculous thought for anyone with land.
We have one spot where the Johnson grass thrives and try to keep bushhogged more frequently.
My horses won’t touch the pieces of Johnson grass in the hay. There isn’t much but what little there is, I find in their haytubs the next morning.
We are in southern Middle Tennessee and need rain; parts of the yard and pasture are dying off. Except where the Johnson grass is; it just grows and grows and grows---------
My feedstore just told me about a new product by Dupont called Pastora.
I am looking into this and meeting with a pasture management person next week to discuss.
Pastora or Panoramic are two fairly new herbicides that should have some effect on Johnsongrass. The only other option is to use a wick with Roundup - if the Johnsongrass is taller than the other grass around it, the wick attachment will catch the Johnsongrass and apply the Roundup but won’t get on the other grasses.
We have had adjacent farms with Johnson grass and have not had a great deal of trouble with it except for several years when someone was helping with the mowing and also helping these other farmers.
We found out then that all equipment has to be hosed down after contact with Johnson grass or the seeds that gather on the mowers will come off on the next field. Once the seeds have germinated then it spreads by rhizomes so in order to really eradicate it you must dig up the plant. Not easy ,but we have done just that to several of our fields.
Also it is toxic to horses under specific conditions . Doesn’t seem to harm cows.
JMHO!
Make sure you aren’t confusing what you think is Johnson Grass with Panicum which looks similar but is shorter. Either way, mowing to prevent it from going to seed everyyear is crucial. I’ve had some in roundbales and found horses won’t eat it. Do some research. Mow the shit out of it!! :winkgrin:
I am pretty sure it is Johnson Grass - my neighbors who have been haying this property for years say that’s what it is and some of it must be 5 feet high right now. I appreciate all the advice - I’m looking into getting a wick applicator bar for my mower and trying some sort of herbicide. Also will try frequent mowing on the worst areas. I can see this will be an ongoing battle! More a matter of just controlling it so it doesn’t spread any further rather than trying to eradicate it which sounds next to impossible.
Johnson grass can’t be easily controlled. If you keep mowing it, it stays low and spreads by rhizomes. Spreads by underground rhizomes even when it’s tall.
The only TRUE way to eliminate Johnson grass is to turn your ground over when it’s either very hot or very cold. That brings the rhizomes to the surface and they die. Once they are gone, the seedlings are easy to control with any good herbicide. Round Up through a wickbar will work on seedlings and very early rhizome shoots, but the plant has a waxy coating on the mature leaves that protects them from chemicals.
If you do try to spray, you’re going to need a surfactant. I usually use dishwashing soap in the mix, but you can buy special surfactants at any ag store.
[QUOTE=cdalt;5021714]
Turns out it is Johnson grass which apparently is very invasive (considered a weed) and I’m told it can have cyanide in it during certain weather conditions like drought or after frost. So if you have experience and/or suggestions for trying to eradicate it, please HELP!!! Thanks![/QUOTE]
johnson grass exists because you do not have enough pressure from other grasses to keep it smothered out…which is to say at some point (in pastures) some genius overgrazed it and allowed the JG to pop up in the now barren areas…
just keep it mowed back under 10 inches and you’ll never have a problem with it thru the summer but it is your job then to plant those things that can smother it out thru the summer and spray it on first sight in the early summer with ignite or liberty or roundup as they say,once it’s made a knee high clump all you can do is mow it
your spray/kill window with it is as a tiny plant
Tamara in TN
[QUOTE=saje;5023134]
Now, Pigweed is another story - I’m at my wit’s end with the stuff![/QUOTE]
ignite will kill it when it is small
Tamara in TN
Can someone post a photo of Johnson Grass? Based on the books, seems to be what we have (and it’s spreading) - but it’s nowhere NEAR tall.
[QUOTE=Tamara in TN;5031716]
ignite will kill it when it is small
Tamara in TN[/QUOTE]
[QUOTE=JanWeber;5032300]
Can someone post a photo of Johnson Grass? Based on the books, seems to be what we have (and it’s spreading) - but it’s nowhere NEAR tall.[/QUOTE]
Tamara in TN
Per one of our old-time extension agents, johnson grass doesn’t tolerate grazing pressure well over time. By keeping horses’ hooves walking all over it, we have eradicated it in a number of our pastures. Which is saying something, given that it was endemic over about 80 acres when we started.
A wick and pesticide is a temporary fix at best. The johnson grass may wither back, but it’ll return, often in the same season. The stuff is really hard to kill with chemicals.
Like Tamara said, make sure to fertilize and help the good grasses grow and crowd out the nasty stuff, and let your horses stomp it to smithereens. Worked for us, anyway.
So that’s Johnson grass, I have it too and Jimson weed and other bad plants. I think my horses ate all the best grass and the weeds took over. We just had the pasture cut and I went around hand spraying and will keep working at it while I have no horses in the pasture.
I wonder if I’m not better off killing everything and planting good seed.
