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How To Control Johnsongrassjohnsongrass

There is no shortage of tough to control weeds that one can encounter on a landscape but one grassy weed that is among the top 10 most difficult to control weeds in the entire world is Johnsongrass. The reason why johnsongrass is such a terrible weed is because of its capacity to be sometimes be resistant to herbicides like Roundup or ALS that would otherwise easily kill a lesser weed. Johnsongrass is known to be detrimental to crop yields and once established, it can get out of control in a hurry.

Eradicating johnsongrass is no easy task. What may be alarming to note is that a single plant of Johnsongrass can produce over 5,000 seeds that can lay dormant for up to 20 years. As tough as a weed johnsongrass is to tackle, you can successfully remove johnsongrass from your lawn if you do your homework and equip yourself with the correct control products which you can find here at Solutions Pest & Lawn.

Check out our Johnsongrass control products below and read further to learn how you can get rid of johnsongrass effectively be following our simple steps.

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How to Get Rid of Johnsongrass: Solutions 4 Step Process

To be able to successfully eliminate Johnsongrass, timing is important as well as using a multitude of control options as opposed to just one because it is such a stubborn and persistent weed that can resist herbicides. While hand pulling is an effective means of control for most weeds if you want to go the organic route, when it comes to Johnsongrass, it will not work.


Hand pulling johnsongrass will likely break the roots, and these broken roots can simply grow back. If you try to plow out the johnsongrass, the rhizomes can spread around and regerminate wherever you spread them. The key will be to discover and treat johnsongrass early and not let it spread and go to seed.  Fortunately, we have some steps and recommendations below which will take care of the Johnsongrass problem quickly and efficiently.


Step 1: Identification. First you need to be absolutely sure that the weed you have growing on your lawn is indeed Johnsongrass. There are some similar perennial grasses that Johnsongrass can be mistaken with called Vaseygrass and guinea grass. It is crucial to identify the weed correctly because while they look similar to johnsongrass they have very different herbicide recommendations. By misidentifying the plant, you can get the wrong recommendations which will lead to an expensive waste of money buying herbicides you don’t need because they won’t work.

Johnsongrass is a vigorous, coarse, perennial grass with scaly root stalks. It reproduces by underground hizomes and seeds. This grass has broad leaves and grows 3 to 6 feet tall. The numerous seeds that develop in the fall are yellow to purplish, occurring in a large, spreading, open seed head.


If you aren’t able to identify it from the image we have posted or the descriptions provided, contact us via identification@solutionsstores.com. Send us a clear photo of the plant and we will properly identify it and then give you a control plan with herbicide recommendations.


Step 2: Inspection. Once you are certain the weed you are dealing with is johnsongrass it is time to carry out an inspection to see how severe of a problem you have on your lawn. Johnsongrass often appears in soil that has been disturbed at the edges of flowerbeds or in newly planted lawns. It can also grow along irrigation ditches or stream bottoms; and along roadsides or cracks between sidewalks. Note where the johnsongrass is growing and how big of a problem you had before proceeding with control options which may be a combination of cultural and chemical control methods.


Step 3: Control. We recommend attacking the johnsongrass early, before the summertime when the growth of the plant is still active and before it gets to the seedling stage. You can try to use Glyphosate or RoundUp QuikPro to control the plant. Mist the herbicide evenly, applying just enough to coat the entire stand of grass but not so much that the herbicide starts dripping off the plant.


Be forewarned that these are non-selective herbicides meaning it will kill all plant life it touches so be careful when applying it around desired plants and spot spraying where needed. Follow the label for recommended rates and application methods.


If your batch of johnsongrass is resistant to glyphosate, you can try another product called Certainty which may have better luck. After applications are made, we recommend drowning the johnsongrass with at least 2 inches of water as this can kill the rhizome network underneath the soil. Shading and baking the johnsongrass under a tarp can also be a good assist to the use of herbicides.

Step 4: Prevention. If you've successfully been able to eliminate johnsongrass, you will want to make sure it doesn't make a return. The seeds of Johnson grass that are missed during the applications can remain viable for as long as 10 years so it is best to prevent the seeds from being spread to begin with via methods such as tilling the soil. Doing so will bring up the rhizomes and seed heads of johnsongrass so they can be disposed of.


Aside from this, the best defense against johnsongrass is a keeping your turf thick and healthy to discourage undesired plants from establishing. Mow at the right height and address any bare spots or thinning via reseeding. If your lawn is lush and strong, it will outcompete weeds like johnsongrass.

By following these steps, you can effectively get rid of johnsongrass from your yard once and for all. If you have any questions or concerns, feel free to email us at askapro@solutionsstores.com or give us a call at 800-479-6583 and one of our friendly representatives will assist you with your order or with any lawn care problems you have.

Not the Weed Problem You Have? Check Out Our Other Weeds On Our Grassy Weed Control Page.


Learn More About Johnsongrass

Johnsongrass (Sorghum halepense) is a warm-season perennial grass weed that is highly disliked by agricultural farmers because of its presence reducing yields in corn, grain sorghum, soybean, cotton and leguminous forages.

Johnsongrass is native to the Mediterranean region of the world and was initially introduced to North America in 1830 as a forage crop and for stabilizing ditches, but has since then been an eyesore and headache to get rid of for agricultural and residential areas because of its tendency to crowd out desirable plants and destroying food and shelter for wildlife.

The weed got its name from one of those farmers who introduced the species to his farm in Alabama in 1840s, Colonel William Johnson. Now, Johnsongrass is found in nearly every state in the country except for Minnesota and has been labeled a noxious weed in 19 states.

This weed is especially tough because it can be poisonous to cattle and horses. If you get an early frost or an extreme drought, you cannot let cattle and horses graze on any johnsongrass because it contains enough hydrogen cyanide to actually kill cattle and horses which can be a serious worry.

Many in the agricultural industry regard this weed as the weed that you "love to hate and hate to love” because of while it can be a frustrating weed in lands where it is growing, at the same time it can also has beneficial qualities. For instance, Johnsongrass is known to attract a host of different bothersome insects, disease pathogens and nematodes of corn and sorghum. On the other hand,  it is not only a valuable forage due to its high yield, palatability and quality for livestock but also is successful in reducing soil erosion as a plant cover alternative.

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Johnsongrass Life Cycle

Johnsongrass is an aggressive perennial weed. The weed produces new shoots from rhizomes or new seedlings will sprout during early to mid-spring. Seeds start to germinate when soil temperatures reach 70 F; however, new shoots from rhizomes will sprout when soil temperatures are 60 F.

In areas of the country where it is cooler, it can be an annual plant. Aside from its effective dispersal techniques, Johnsongrass is prolific because seeds can stay dormant and remain viable for as long as a decade, and produce plants over several years. Johnsonhrass can produce an enourmous amount of seed and a single plant can develop more than 80,000 seeds in a single season.

It takes between 3 to 4 weeks rhizome to develop from a seed. When rhizome is established, it starts producing a large number of shoots and roots (a single Johnson Grass can produce more than 5,000 nodes in a single season).

When the temperature starts to rise in the springtime, new-formed rhizomes and old ones which made it through the winter start to form a large number of shoots. The flowering stage starts two months after the growth begins, and each flower panicle of Johnsongrass forms hundreds of seeds in a single blooming season.

Seedlings grow slower than rhizomes and require a higher temperature to germinate than a rhizome needs to produce a sprout, but both develop quickly enough to take over an area where they have established.

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Johnsongrass is A Toxic Weed That Produces Cyanide

It may worry some farmers and livestock to know that johnsongrass can be potentially harmful to farm animals. Usually this is under environmental conditions such as drought, extreme heat, frost and heavy rain. In these conditions, Johnsong rass may develop cyanide, but these toxins can vary among Johnson Grass population.


Cultural Methods of Johnsongrass Control

Johnsongrass spreads by seeds and underground rhizomes so as a result, this weed can be difficult to control with one method alone. For the best result you need to combine the use of herbicides with organic, cultural control methods. The goal is to not only the prevention of seed production and spread of seeds, but you also must destroy seedlings before rhizomes are formed and kill existing rhizomes too.

Hand control and hand pulling is not recommended because it will only break the plant and leave the rhizome of the plant undamaged, so the plant will grow back again, rendering this method ineffective.

But, you can try to remove the plant physically by removing clumps and small, individual plants in early spring before they begin to produce seeds. This should preferably be done shortly after rainfall when the soil is soft. Pull out the whole plant and the rhizome. This is a crucial step if you want to prevent the seeds to spread to areas that are not infested.


Additional Resources For Johnsongrass Control

Johnsongrass Control - University of Missouri Extension



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