Turfgrass's Least WANTED Weeds - Cogongrass

December 5, 2019

Description

Perennial grass that varies greatly in appearance. The seeds are cylindrical in shape, 2-8 inches in length, are silvery white in color and resemble light fluffy dandelion-like seeds. However, the seeds are briefly visible as cogongrass flowers for only a short time. It can be identified by bright green leaves that grow from 4 inches to up to 6 feet in height. The leaves have sharp serrated margins and a distinctive white midrib. Though another distinctive feature is that cogongrass lacks above-ground stems, as leaves arise directly from the this weed's rhizomes.

Where it Grows

It is found on every continent, although it does not tolerate cool temperatures. In US, cogongrass extends as far west as Texas and as north as South Carolina. It infests turf, ditch banks, pastures, golf courses, and along forest tree lines. It thrives on low-fertility soils from fine sand to heavy clay.

Impact

This weed has two methods of spreading: the dispersing of its 3000 seeds per plant by way of wind currents, but the main way it spreads is through a network of rhizomes. When established, this perennial weed is very difficult to get rid of. In areas with killing frosts, the leaves will turn light brown during winter months and present a serious fire hazard. 60 percent of its growth is below the surface in a dense web of sprawling, dirt-hugging roots. This allows the plant’s rhizomes to cause physical injury to other plants by penetrating roots with its sharp rhizome tips. Like many other weeds, it is highly competitive for water and nutrients.

How to Manage

If cogongrass has invaded your turf, then you need to take aggressive action before it spreads. Tiling or digging out the grassy weed can be an option; however, you can run the additional risk of spreading the rhizomes and increasing the invasion. Multiple treatments of a non-selective herbicide are recommended to control and completely eradicate the weed. The best way to avoid this weed is prevention. Regular nutrient treatments and applying a pre-emergent herbicide will keep your turfgrass healthy and dense, reducing the chance of a weed infestation and assuring you maintain your beautiful turf.

To find herbicides available to control a variety of weeds, visit TurfCare's online 2019 Product Catalog for details. For information on locating a distributor to order, CLICK HERE.

 

References:

https://www.invasivespeciesinfo.gov/profile/cogongrass#cit

http://southernforesthealth.net/plants/cogongrass/cogongrass-biology-and-management-in-the-southeastern-u.s

https://plants.ifas.ufl.edu/plant-directory/imperata-cylindrica/

https://www.cogongrass.org/identification/

Photos:

https://hgic.clemson.edu/factsheet/cogongrass/

https://www.aces.edu/blog/topics/forestry-wildlife/stop-cogongrass-hitchhikers/

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