Tuesday, May 25, 2010

Cogongrass - Invasive Weed

University of Georgia Thomas County Ag Agent and Warnell School of Forestry specialist discuss cogongrass.
Visit www.thomascountyextension.com or www.cogongrass.org for more information.
Key Identification Features of Cogongrass
Flower/Seed head

Cylindrical in shape
2-8 inches in length (total flower or seed head)
Silvery white in color
Light fluffy dandelion-like seeds
Blooms from late March to mid June (flower timing depends somewhat on local climate)

Blades up to 6 feet long
About 1 inch wide
Whitish, prominent midrib, that is often off center
Margins finely serrate
Some leaves are very erect, but some may droop or lie flat
Often light yellowish-green in color
Could have a reddish cast in fall/winter or brown after frost or freeze
Plant Base

No apparent stem
Leaves appear to arise directly from or close to the ground
Overlapping sheaths give a rounded appearance to the plant base
All vegetation doesn't arise from one dense clump, instead the plants are more spread out
Light-green to yellowish in color, or could be reddish
Often a lot of thatch around base
Leaf collar/Ligule

Ligule is a thin-fringed membrane
Leaf sheaths overlapping, giving the plant a round appearance
Hairy (the ligule is the most hairy part of the plant, the plant base may also be somewhat hairy)

Dense mat
Many sharp points
Covered in flaky scales
Bright white under scales
Strongly segmented
Whole Plant

Densely growing patches
Tall grass (up to six feet, averaging 3-4 feet)
Circular infestations
Plants often turn brown in winter (at least partially, but may depend on local climate)

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