:mad: Just discovered what this is, I have 2 large stands of it, one about 30 ft across and the other 20 ft. Grows in a perfect circle. I’m going to call the extension office when I’m off again. Has anyone had luck smothering it with black plastic? Otherwise I’ll probably wait til it stops flowering, mow it and bathe it glyphosate.
Just googled it, looks horrid!! Where are you at? Maybe your ag ext office can help? Google says you have to dig out or till 6 to 8 inches first to effectively kill the root.
I would mow it RIGHT NOW, prevent it setting seed!! Get those flowers GONE! You can then deal with the roots after. The seeds getting spread by birds, blowing in the wind, is going to spread this stuff further.
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Never heard of this type of grass so did a quick search and found
https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs141p2_021449.pdf
It is a Federally classed noxious weed :eek: (and designated as world’s seventh worst weed). It is highly flammable.
There is a section in the above document about Controlling Cogongrass.
Cogongrass is commonly spread by contaminated equipment so, when possible, do not work in an infested area. If it is unavoidable, do the contaminated areas last and clean vehicles, equipment, and clothing before moving into an uncontaminated site.
Mowing to keep it short and controlling seeds would be part of the strategy but note the above about equipment contamination being a common cause of it spreading.
Many herbicides have been tested to con- trol cogongrass, but only the active ingredients “glyphosate” or “imazapyr” have much effect. Both of these herbicides may cause injury to non-target plants. With all herbicides, follow the label directions carefully.
The bolding is mine. Glyphosate and imazapyr are effective herbicides (in general) but overspray needs to be carefully managed as both herbicides can negatively impact other types of plants.
Controlling cogongrass can be quite dif- ficult. Since it is found around homes, on public properties, paved and earthen roadways, forestland, stream banks, and farmland, there are not any generic recommendations for control. Recommendations should be site specific and considerate of the surroundings.
I would concur with contacting your county extension ag agent as well as looking through the list of additional information.
Additional info.
The publication mentioned in the USDA document published by the Alabama Cooperative Extension, ANR-1241 is old (updated 2005) and has been archived.
More current would be Cogongrass Management FAQ published by the Extension.
Of note IMO would be
[h=1]Q: What is the best herbicide to treat cogongrass?[/h]
Two herbicides, glyphosate and imazapyr, are effective against cogongrass. However, they are generally situation specific and require multiple treatments for complete control. Glyphosate is the safest option when treating cogongrass around desirable trees, shrubs, or other vegetation but is frequently less effective than imazapyr. Imazapyr is extremely effective but cannot be used near most desirable vegetation, unless severe injury or death of the vegetation can be tolerated. Some pines, including loblolly pine, are tolerant to imazapyr. Longleaf pine, however, is not tolerant of high rates of imazapyr.
Bolding is mine. I am a Master Gardener in my county (which is not in Alabama 
). Imazapyr is an herbicide we tend to not recommend as often as glyphosate due to the potential effects on surrounding plant growth.
I went to the Alabama A&M & Auburn Universities Extension page and searched on cogongrass. There are additional pubs besides the FAQ.
I decided to mow it anyway. I don’t have any current animals but this is where I’m going to build my house next year, I’m glad I realized what this was and that it’s not just a pretty fluffy grass like I thought. So I guess glyphosate seems to be the standard so when it stops raining I will drench it with herbicide. It’s been there since I bought the property, I just didn’t know it was such a big deal :no: Hopefully I’ve caught in time to contain it.
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Make sure you clean off your mower when done so you don’t contaminate new areas of your property.
Keep in mind that glyphosate is a systemic herbicide. When you treat, don’t run out the next day and wonder why nothing died. That is not how it works. You spray (using appropriate personal protection cautions ). Glyphosate is taken up by the plant material above ground and has to be transferred to the roots where it will begin to kill the roots. It may take a few days or more before you see visible signs that you’ve treated with glyphosate.
I find the glyphosate works well on hotter days, seemingly getting absorbed better with the heat. Don’t forget to use a surfectant, like Dawn dishwashing soap in the herbicide. This helps the herbicide to stick to the plants better, so herbicide will work more effectively.
I will definitely add some dish soap to my herbicide, anything to make it more effective.
Read the label of the glyphosate product you are planning on using. You can get glyphosate products with a surfactant already added.
You may want to also reconsider mowing as the leaves are needed to take up the glyphosate (or don’t scalp the grass).
A lastly thought. You might, if the infestation is bad, ask someone who does pest management professionally. Many pesticides have formulas for the residential user and stronger formulas for professionals who are licensed to apply them.
Treat it with glyphosphate mixed to the recommended ratio for it. Do it on a hot day when the plants are thirsty. Do not mow it first- you want it to have the surface areas to soak up the herbicide.
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I will disagree on not cutting immediately. OP says grass has flowers NOW. Even spraying it yesterday with the glyphosate, it will take 10 to 14 days to just start showing yellow. That time period will allow the grass finish setting seed that can be viable for reseeding when she does cut dried, dead long grass later. Letting it dry long, in place, covers any new growth, lets those seeds dry for being spread when cut for removal.
Cutting length by mowing now, she has removed flowers, not allowed grass to reach the seed stage. I would rake and remove the cut stuff, dispose of it safely. Then wait a couple weeks for grass to start growing again, then spray it. Leaves are new, shorter, so they should absorb herbicide faster, better. You can see where the spray wets down the shorter grasses, to insure good coverage. You want those plants soaked, with herbicide dripping off, to do a complete job. Wear protective clothing, long sleeves, long pants, socks, hat, mask if there is any wind, rubber boots, to keep it off of you. Spray low to the ground so it minimizes any drift of spray.
You SHOULD have warmer to hot days by two weeks from now, heat being helpful in herbicide absorbtion, to be more effective. I would be checking the sprayed grasses in seven days, see if there is yellowing yet. Might take longer with cloudy days, cooler temps, to see yellowing. Regardless, I would respray at 21 days to get anything trying to grow there. Keep checking for any growth. Those roots will be very determined to send up leaves, so you need to be diligent with respraying visits over the summer.
On buying your herbicide, read the contents labels. Roundup is one brand selling glyphosate, but there are OTHER BRANDS also selling it, and much cheaper if you buy concentrates. Surfectant may be included but not always, read the labels. Huge savings buying concentrates over ready-to-spray herbicides. Check sprayer for clogs, adjust the sprayer tips, filters clean, so it soes spray well, BEFORE you fill it with herbicide! Ha ha
You do need to read mixing directions, to get proportions correct. Use measuring cups, or marked bottles with ounces, for the herbicide, while wearing rubber gloves. I fill my sprayer with water FIRST, then add the herbicide and needed surfectant and screw the lid down tight. Putting them in first will cause excessive foaming during fill, making you wait till it subsides to finish filling. Travel to the field should mix it fine.
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I agree with your assessment.
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