Extension Report

Baldwin County Extension Office

302A Byrne Street

Bay Minette, AL  36507

Telephone (251) 937-7176 or

928-0860/943-5061 ext. 2222

FAX (251) 937-7285

Rudy Yates

Regional Extension Agent

Agronomic Crops

May 31, 2011

Cogongrass Flowered Out

You can’t miss it when cogongrass is in full bloom.  During my travels, I’ve noticed several circular patches of cogongrass off the side of the road.  Those white flower heads stand out in a sea of green.

Cogongrass creates a number of problems.  It reduces forest productivity, destroys wildlife habitat and displaces our native vegetation.  Cogongrass is fire-adapted and will burn hot.  Wildfire in an established, thick cogongrass stand can kill mature and seedling trees and native plants.  It’s not even good for livestock forage.  The leaf margins are serrated and rough to the touch, which can cut the tongue of grazing animals.

Cogongrass is an aggressive perennial weed that can get 1 to 6 feet tall.  The leaves can be ½ to 1 inch in width and often look yellowish-green.  The leaves’ midrib is generally off-center, especially near the base of the leaves, and can have a whitish appearance.  The leaves appear to come right out of the ground but there are short stems present.  The rhizomes (underground stems) are scaly, segmented and sharply pointed.

Cogongrass blooms in the spring, sometimes early summer.  The flowers are silvery white and range from 2 to 8 inches in length.  One flower can produce 3,000 silvery white seeds, which are light and fluffy.  The seeds can be blown off with a breeze like dandelion seed heads.

Cogongrass spreads by seeds and rhizomes.  Seeds carried by equipment and vehicles or pieces of rhizomes in soil can move this aggressive weed and start an infestation.  The breeze of a vehicle passing by a patch of flowered cogongrass on the right-of-way of a county road or highway can spread the weed if the seed are mature.

Cogongrass control varies according to age of the patch, rhizome density and depth, and your situation.  One of our publications, ANR-1241 – WANTED DEAD NOT ALIVE: COGONGRASS, explains control measures based on the age of the patch and different situations.  Herbicides containing the active ingredients glyphosate and imazapyr have a significant effect on cogongrass.  These herbicides are listed in ANR-1241.  This publication, along with other information such as ANR-1321 – Stop Cogongrass Hitchhikers, can be accessed on-line by going to www.aces.edu and typing in cogongrass in our website’s search engine.  Other cogongrass websites for Alabama landowners are www.alabamacogongrass.com  and http://www.forestry.state.al.us/ .

If our office can be of any assistance, please do not hesitate to contact us.

Email address: yatesrp@aces.edu

Phone number: 937-7176 or 943-5061, 928-0860, ext. 2222

Baldwin County Extension Programs are supported by the Baldwin County Commission.

The Alabama Cooperative Extension System (Alabama A&M and Auburn Universities) in cooperation with the U.S. Department of Agriculture is an equal opportunity educator and employer.