We have a fairly large area (1/3 acre) of our yard which is almost completely johnson grass. We would like to put buffalo grass and wildflowers in this area, but does anyone know how to get rid of the johnson grass? We have been organic for five years and don't want to use a toxic chemical.

Mow it down repeatedly or bring in livestock. They love the taste but sometimes it can be toxic. Be sure you know when it's toxic if you're considering animals.

You might try spraying 20% vinegar on the Johnson grass. Look for it a Lowes or other places with an organic gardening section. Many feed stores carry it.

fowl_pat,

Since you don't have a location listed, I have no idea if livestock is an option for you. Since I've never had livestock, I don't know if that would work or not.

Though it has been years since I had to deal with Johnson grass, I can tell you that I defeated the stand I inherited by mowing it each week and an occasion hand pulling session after a rain. Believe me, it was more mowing than weeding.

It does surprise me that you indicate that you have been organic for five years and still have this problem. I found that Johnson grass was one of the easier weeds to eliminate. Maybe this is a new location for you? It would not take five years of mowing to eliminate Johnson grass. IIRC it took about two mowing seasons.

Mow it down before it forms a seed head or matters only get worse. Don't think livestock will kill it. The toxic form is when it is stressed like a lack of rain and it starts wilting. Causes prussic poisoning, can kill a cow within minutes of taking a bite. Best to try to work on the root system. Tilling doesn't help unless you collect and discard all of the root sections, nearly impossible.

We mow our yard regulary. I have noticed more Johnson grass, not less. If we need to mow it really short - well, our lawn would suffer from the heat if we scalped it. Can someone clarify why mowing should help, but it doesn't help us?

flowerlover-
I have no idea of your horticultural knowledge so bear with this question. Are you sure you have johnson grass vs dallis or crab?
Tony M

Well, my husband says it is Johnson grass. When pulled out of the ground, each plant has a wide base, and the blades are thick and grow out at an angle - looks like a crown. Isn't that Johnson grass?

The only pictures I have of JG are from a mature plant. Look for stems growing from the clump with a seed head that is perpendicular to the stem, sort of like a flag in the wind. That is dallis grass, see picture #7 in the attachment.
http://www.noble.org/Ag/Forage/KnowYourGrasses.pdf
Tony M

Johnson grass is one of the ones that grows 7 feet tall if you let it. Dallis and crab both grow low. Crab is downright short.

Might try to identify it by root system. Johnson grass has a white root system that is jointed every 2 or 3 inches. Each joint usually has small roots or a spur growing from it. The joints usually have a brown coloring on them. White root is sometimes sort of flat instead of totally round, 1/4 to 3/8 inches in diameter. Somewhat similar above ground as some of the Lilies, I think Tiger Lily is similar. I stated in earlier post that livestock didn't have much effect on Johnson Grass. Later remembered thatigs have been reported to be effective on it. They love to root or dig up the roots and eat them. And to kill Johnson Grass you have to attack the root system.

I really enjoyed the link of pictures of grasses but still can't identify most of what we have on our 20 acres. One day I'll learn how to post pictures from our camera. I DO know johnson grass & we had a lot of it when we bought the land in '02. We have mowed as often as we could w/tractor & bush hog that continues to die and of course we've not removed the mowed grass. We have VERY little johnson grass left. We have no water there so mowing is all we've done.
Patty