Cogongrass

About

Cogongrass is a federal noxious weed from Asia that forms dense, fire-prone stands across the Gulf South. If you think you have it, report it and get help, because digging, tilling or mowing seedheads usually spreads it.

Also called cogon grass, Japanese bloodgrass, Red Baron grass

How to identify it

Look for

Leaves rise straight from the ground with no visible stem. Each leaf is long and narrow with a white midrib set off-center and rough, sandpapery edges. In spring it shows fluffy, silvery-white seedheads 2 to 8 inches long, and underground are white, segmented rhizomes with sharp tips.

Look-alikes

Johnsongrass has wider leaves and a branched seedhead, and broomsedge grows in bunches with visible stems. The red ornamental 'Red Baron' Japanese bloodgrass is a form of this same species.

Where it grows

Roadsides, pastures, pine stands and open fields, spreading into yards; it grows in sun or part shade and many soils.

When

It flowers and sheds seed from about March through June, and the leaves turn straw-colored and very flammable in winter.

How it spreads

By wind-blown seed and by rhizomes carried in soil, on equipment, shoes and clothes.

Most common in

Where it is regulated

It is on the USDA federal noxious weed list, so moving it across state lines without a permit is illegal.

What to do, gentlest first

Start at the top. Weed killers are a last step; always read and follow the label.

1. Report it and don't move soil Prevent

   Report suspected cogongrass to your county Extension office or EDDMapS (in South Carolina, Clemson's Department of Plant Industry). Clean shoes, clothes and equipment after walking through it, and don't move soil or plants from infested ground.

   Never plant any form of this grass.

2. Don't dig, till or mow seedheads By hand

   Rhizome pieces regrow and much of the plant lives underground, so digging and tilling spread it. Don't mow when seedheads are present.

   Don't burn it: burning spurs new growth, and its dry leaves are a wildfire hazard.

3. Professional herbicide program over several years Conventional spray

   Extension services recommend repeated glyphosate and imazapyr treatments over several years, well timed and combined with other steps. For most homeowners, get help from Extension or a licensed applicator.

   Read and follow the label. Many lawn weed killers also kill garden plants, so keep spray and drift off beds and vegetables. These sprays kill any plant they touch.

Uses, wildlife and pets

For wildlife

Poor forage: Mississippi State notes animals that eat it tend to lose weight.

Pets

Not listed by the ASPCA.