Bladey grass, known in the US as cogongrass, is an Asian grass that has become one of the most troublesome invasive plants in the Southeast. It spreads through a dense mat of sharp-tipped underground stems and fluffy, wind-borne seeds, crowding out native plants and fueling unusually hot fires. It is listed as a .
Appearance
- Appearance
- Grows in spreading, often circular patches of light yellowish-green leaves 2–3 ft (60–90 cm) long, sometimes up to 6 ft (1.8 m). There is no obvious stem; the leaves rise from ground level.
- Leaves
- Blades are about 0.5–1 in (1–2.5 cm) wide with sandpapery edges and a whitish midrib that usually sits off-center. Dead leaves stay standing over winter as reddish-tan thatch.
- Flowers
- Cylindrical seed heads 2–8 in (5–20 cm) long start purplish-tan and turn silvery-white and fluffy.
- Flowering time
- Blooms from about March to June depending on local climate, and can bloom again after mowing or other disturbance.
Look-alikes
Where it lives
- Typical habitats
- Roadsides and rights-of-way
- Open pine forests and plantations
- Old fields and pastures
- Range
- Native to warm parts of Asia, Africa, Australia, and southern Europe. In the US it is mainly a problem across the Southeast, and it has spread to nearly every county in Florida.
- Preferred conditions
- Prefers full sun to partial shade and tolerates poor, sandy, or clay soils. It does poorly in sites that stay wet or are tilled often.
- Flowering
Flowers Mar–Jun
Flowers Mar–Jun
Life cycle
- Seed dispersal
- A single plant can make up to about 3,000 seeds, carried on silky hairs by the wind.
Growing it
- Propagation
- Also spreads by white, segmented rhizomes that can reach about 4 ft (1.2 m) deep. Small rhizome pieces moved in soil or on equipment can start new patches.
Name and classification
- Varieties and forms
- 'Red Baron,' sold as Japanese bloodgrass, is a red-leaved garden form. Its sale is prohibited in many Southern states because green shoots can appear, and those should be removed.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
- Status
- Federal noxious weed. Several Southeastern states, including Alabama and Arkansas, regulate it as well.
- Threats
- Cogongrass fires burn hot enough to eliminate nearly all native plants in their path, while its own rhizomes survive and regrow quickly. Its roots may also release chemicals that weaken nearby plants.
Culture and stories
- Culture and stories
- It arrived in Alabama by accident in the early 1900s, likely as packing material. In the 1930s and early 1940s it was planted on purpose in Florida as possible forage and to hold soil.
- The name cogongrass comes from the Tagalog word kugon. In Southeast Asia the grass is valued for thatching roofs and weaving mats.
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