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Cogongrass Imperata cylindrica

Other Common Name(s):

This plant is an invasive species in North Carolina
Description

Japanese Bloodgrass is an extremely aggressive weed that is considered invasive in North Carolina.  It probably originated in Africa and Asia and was accidentally introduced in LA in 1912 and then intentionally to FL in the 1930s. It was used as packing material in the past and then for erosion control and animal forage. It quickly spread and invaded areas such as pastures, fallow fields, forests, and highway and powerline rights-of-way. It spreads rapidly through scaly rhizomes and quickly becomes difficult to manage. It is also highly flammable and increases the risk of wildfires. The plant regenerates after a fire and quickly takes over an area.

The green leaves grow up to 30 inches tall and 1/2 to 3/4 inches wide. They are finely toothed and embedded with sharp silica crystals. The rhizomes are extensive and can penetrate 2-4 feet deep. It rarely flowers in its northern range. In more tropical areas it freely flowers with 16-inch panicle inflorescences. 

There is a cultivar called 'Red Baron' that is supposedly sterile but it has been known to break sterility and revert back to the green form. It is not wise to plant this cultivar either.

This grass is considered the seventh worst weed in the world and listed as a federal noxious weed by USDA Animal and Plant Health Inspection Service - Plant Protection and Quarantine. See alternative grasses to grow to the left.

Fire Risk: This plant has an extreme flammability rating and should not be planted within the defensible space of your home.  Select plants with a low flammability rating for the sites nearest your home. 

Insects, Diseases, and Other Plant Problems:  No serious insect or disease problems.  This plant is invasive. 

See this plant in the following landscape:
Cultivars / Varieties:
'Rubra'
Tags:
#invasive#drought tolerant#high maintenance#air pollution tolerant#fast growing#fire high flammability#fire extreme flammability#aggressive#Noxious Weed List#self-seeding#poor soils tolerant#black walnut toxicity tolerant#weed#federal noxious weed list
 
Cultivars / Varieties:
'Rubra'
Tags:
#invasive#drought tolerant#high maintenance#air pollution tolerant#fast growing#fire high flammability#fire extreme flammability#aggressive#Noxious Weed List#self-seeding#poor soils tolerant#black walnut toxicity tolerant#weed#federal noxious weed list
  • Attributes:
    Genus:
    Imperata
    Species:
    cylindrica
    Family:
    Poaceae
    Uses (Ethnobotany):
    It has been used in traditional medicines.
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Africa, Europe, Asia
    Fire Risk Rating:
    extreme flammability
    Dimensions:
    Height: 2 ft. 0 in. - 4 ft. 0 in.
    Width: 2 ft. 0 in. - 4 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Weed
    Habit/Form:
    Clumping
    Erect
    Spreading
    Growth Rate:
    Rapid
    Maintenance:
    High
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    Loam (Silt)
    Sand
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Available Space To Plant:
    12 inches-3 feet
    3 feet-6 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Description:
    fuzzy, white, and plume-like seed heads
  • Flowers:
    Flower Inflorescence:
    Panicle
    Raceme
    Flower Bloom Time:
    Summer
    Flower Description:
    Infrequently flowers in northern parts of its growing region but flowers freely in tropical areas. 16" long panicle that branch out into racemes.
  • Leaves:
    Leaf Color:
    Gold/Yellow
    Green
    Leaf Shape:
    Linear
    Leaf Margin:
    Serrate
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    Basal stiff leaf blades are yellow-green 3/4" wide and up to 30 inches long with tiny serrated margins, light green or white midribs that are of center and pointed tips. Margins are finely toothed and are embedded with sharp silica crystals. Upper surface has a few hairs near the base, undersides are smooth.
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Resistance To Challenges:
    Black Walnut
    Drought
    Pollution
    Poor Soil
    Problems:
    Invasive Species
    Weedy