PlantFiles: Johnsongrass
Sorghum halepense

HORRIBLE plant, I canNOT get rid of it!! It's in my front yard right on the corner and I've done everything - even KILLED the stuff with spray, pulled it by its roots, but I can't get rid of it! HELP!!!!!!!! It's taking over my yard!!!

Johnsongrass Sorghum halepense is naturalized in Texas and other States and is considered an invasive plant in Texas,

There might as well be at least one positive note about this plant. It may be invasive here in Pennsylvania according to what was said above, but Johnson Grass doesn't bother me in the least. In this area, it doesn't seem to pose much of a problem. It’s not as invasive in these parts as it is said to be in many other places. I've never heard a complaint about it from a local person.

To me, it's a rather attractive plant. At least the flowering tops are anyway. Here the inflorescences can get to be a deep violet color and along the country roads, it looks quite charming when seen in a passing car. It's even more beautiful when observed up close during a walk in the countryside. It looks like a sea of purple at times in the fall.

I like to collect bunches of the flowering heads and use them in making decorations. Depending on where you display them, they can keep their color for some time. And they do look unique when displayed alone in their own vase.

Because of the amount of negative comments above and its being invasive, I won't recommend it for use in the home garden. However, I see nothing wrong in using it for home decorations and general display around the home. I can think of lots of other plants that are more invasive and much less attractive than Johnson Grass.

I also have this info to add from "The Encyclopedia of Edible Wild Plants of North America: Nature's Green Feast" by Francois Couplan, Ph.D.

"Sorghum halepense, Johnson Grass - from the Mediterranean area - is cultivated as a forage plant. ...The grain of S. halepense and S. vulgare (=S. bicolor) is edible. It is used extensively like millet as human food in various parts of the world, especially in tropical Africa and Asia. The grains of S. halepense were reportedly eaten by Pima Indians of Arizona after the plant was introduced by the Spaniards. Most commonly in developed countries, the grain is used as cattle feed.

The leaves of both species are rich in hydrocyanic acid (hydrolyzed from the glucoside dhurrine) and have poisoned livestock. The HCN content varies greatly according to diverse factors such as soil quality, available water quantity, and age of the plant. It is generally believed that thoroughly dried sorghum hay is no longer toxic. Older plants, as well as the stems of younger ones, are relatively free of HCN."

2 acres of Johnsongrass when we first moved in :( We mow and mow early, almost scalping the area. Then we rake with a heavy, long toothed attachment. We then mow again. After 5 years, we've got it mostly under control, but keeping it mowed early and often seems to be a key. We are fortunate to have a tractor.

Where it self seeds in our gardening areas is a different matter - hand pulling is all that works as it's mixed in with perennial beds. We usually spend 3-4 days early spring going at it and we never have licked it.

I concur with all the other comments regarding its razor sharp leaves; please wear heavy duty gloves when hand pulling.

When I was young during the dustbowl days, we lost all our cattle due to their breaking down a fence to get to a patch of Johnsongrass. I remember the dispair of my folks at the sight of more than 50 head of cattle all dead. They were able to sell the hides for about 50 cents each. Total wipeout.
When in Highschool I worked for a farmer that was eradicating 400 acres of heavy infestation. We used a plough called a "Hammy" to cause the roots to be on top of the soil. It took almost 3 years of constant ploughing to get it under control.

trois

This grass is the BANE of my existence, as it runs rampant through most of my farm. Root systems spread long & deep, making pulling/digging the stuff out impossible. And even though I am an organic gardener & have way too much of the stuff to spray anyway, I've heard that even the most potent of herbicides won't eradicate it without repeat applications.

Although in some parts of the country the mature plant is cut & dried for livestock hay, it IS true that when stressed - i.e. subjected to frost or drought conditions - the plant is quite toxic to livestock, especially horses (which I raise), & has also been known to cause unthriftiness in beef cattle. I believe the poisonous compound that becomes concentrated in the stressed plant is cyanide. Even the plentiful herds of deer won't touch the stuff - that alone should tell you something.

As someone else pointed out, a number of communities have banned this plant. Here in Virginia, several counties also DO levy fines on farmers for allowing it to flourish; in fact, if a farmer does work outside the county where the plant is allowed, & uses his own equipment, he must thoroughly wash everything down before returning to his in-county farm. That's how much the stuff is hated here.

The only thing that I have found that seems to help keep it in check somewhat is constant mowing to keep the plant from maturing. I've even been able to eradicate it completely from one field by this method - although it did take several years of diligence.

Johnson Grass is a noxious invasive weed introduced from the Mediterranean as a forage for livestock by William Johnson of Alabama in 1840. Clumps of it overrun pastures, it invades the lawn, and it's impossible to eradicate. The best bet to get rid of it is with Roundup. I have heard in times of drought the foliage can be poisonous to livestock.

actually, this weed is illegal in our community and if left to grow without cutting there have been citations with fines. It is hard if not impossible to irradicate, but must be kept cut short so it does not "seed" and reproduce even more.

This WEED is definately on my hit list. Razor sharp edges make it very difficult to handle. Apparently being a perennial keeps it from dying out when mowed enough to keep the seeds down.

Information from plant.usda.gov

Arkansas:
johnsongrass Noxious weed
California:
johnsongrass C list (noxious weeds)
Colorado:
johnsongrass Noxious weed
Delaware:
johnsongrass Noxious weed
Idaho:
johnsongrass Noxious weed
Illinois:
johnsongrass Noxious weed
Indiana:
johnsongrass Noxious weed
Kansas:
johnsongrass Noxious weed
Maryland:
johnsongrass Noxious weed
Missouri:
johnsongrass Noxious weed
Nevada:
johnsongrass Noxious weed
Ohio:
johnsongrass Prohibited noxious weed
Oregon:
johnsongrass "B" designated weed
johnsongrass Quarantine
Pennsylvania:
johnsongrass Noxious weed
South Dakota:
johnsongrass Regulated non-native plant species
Utah:
johnsongrass Noxious weed
Washington:
johnsongrass Class A noxious weed
johnsongrass Noxious weed seed and plant quarantine
West Virginia:
johnsongrass Noxious weed

Extremely weedy in the Southeastern U.S., especially throughout much of Florida and in my south Florida area! Spreads everywhere, can grow through the gaps and cracks in a sidewalk or driveway, and crowds out native plants! One of the most invasive plants I've seen - I agree with all the comments about this plant! Please DO NOT PLANT THIS PLANT!

MORE FACTS - Johnsongrass is also invasive throughout much of the southern and possibly central U.S.

Farm irrigation canals in parts of the San Joaquin Valley have unfortunately been the cause of rampant growth of this awful weed. It is all but impossible to irradicate, once established. Ditto on all the above comments!!!

I agree with everything everyone above said. This plant is THE most invasive plant I've ever come across!

Invasive and nearly impossible to get rid of. Spread by hundreds of seeds or by roots....some nearly 2 feet deep.

Has even caused some farms and orchards to be abandoned because it is nearly impossible to irradicate.

It can also be poisonous to livestock during early stages of growth or during drought.

I recommend being very careful when attempting to pull this plant by hand. The leaves can be almost razor-sharp, so care should be taken to ensure the soil is moist enough to be worked, wear gloves, and grasp the plant firmly near its base.

Unfortunately, most mechanical removal methods tend to leave enough rhizomes to bring forth another healthy stand of this weedy grass.

Johnsongrass is a vigorous, course, perennial grass with scaly root stalks capable of reproducing by underground rhizomes and seed that forms dense clumps .This plant has broad leaves and grows to a height of three to eight feet. The seeds developed in the fall are yellow to purplish in color, Johnsongrass is considered a weed in cultivated fields, waste places and along irrigation ditches and stream bottoms. Johnson grass is regarded as a major agricultural weed, especially in corn fields where it forms tall, dense stands. The dead stems and leaves of this perennial herb cover the ground all winter. It aggressively crowds out native species. When cut the underground rhizomes of Johnson grass resprout forming new plants. The plant is resistant to many common herbicides as well. These factors make Johnson grass a pernicious weed. Small stands may be controlled by hand pulling the plants when the soil is moist. But it very hard to hand pull and get all the root.