Sudangrass quick facts

What is sudangrass?

Sudangrass (Sorghum x drummondii) is a hybrid between two types of grasses in the genus Sorghum: sorghum (Sorghum bicolor) and common wild sorghum (Sorghum arundinaceum), which is a grass originally from Africa and South Asia. Sudangrass is a fast-growing, productive forage grass commonly used as livestock feed (for grazing or to make hay or silage) and as a cover crop.

Sundangrass is tall (3­–8 feet or 0.9­–2.4 meters) with slender stems and large leaves. The panicles and spikelets range in color from red to purple, bronze, cream, yellow, and black. The color can add decorative value, although sudangrass is not generally cultivated as an ornamental.

Where is sudangrass found?

Sudangrass originated in subtropical and tropical regions of eastern Africa. It was first documented in the country Sudan, giving the grass its common name. In other African countries—such as Nigeria, Ethiopia, Kenya, Tanzania, and much of South Africa—sudangrass is used as a forage crop. Sudangrass is now cultivated all over the world.

How is sudangrass grown?

Sudangrass grows in subtropical and tropical regions and prefers warm to hot temperatures, growing best at temperatures between 77ºF to 95ºF (25ºC to 35ºC). It can grow in a variety of soils, including clay, loam silt, and sand. Sudangrass is drought tolerant and prefers well-drained soils. However, in longer periods of drought, sudangrass may accumulate prussic acid, which can be deadly to livestock. For this reason, sudangrass as a forage performs best in areas with around 20–28 inches (about 51–57 centimeters) of rainfall per year. Since sudangrass is a tropical crop, it prefers full sunlight.

How is sudangrass used?

Sudangrass can be used as a forage or can be cut green for feed after a relatively short period (5 to 8 weeks) of growth, or when the grass reaches about 18 inches (46 centimeters) high. It is also harvested for hay and silage when it reaches about around 30 inches (76 centimeters) high. If harvested, the grass is cut above the base to allow for regrowth.

What are the benefits and drawbacks of sudangrass as a forage grass?

Sudangrass has several characteristics that make it advantageous to farmers. It is known for its high yield and fast rate of growth. Because it grows quickly, multiple crops can be harvested during the growing season. Farmers can thus save money and buy fewer seeds while still producing abundant hay, silage, and/or forage grass.

Sudangrass is nutritious and contains carbohydrates, proteins, and minerals. It meets most of the nutritional requirements of livestock like cattle, sheep, and goats, thus promoting animal growth and milk production. Sudangrass is suitable for silage production, allowing it to be preserved for use during times when forage is less available.

Sudangrass can accumulate nitrates and prussic acid (hydrogen cyanide) in its tissues under certain conditions of stress, such as during a long drought, after a frost, or following overgrazing. Nitrates and prussic acid can poison livestock, causing health issues and possibly death. Because of this, sudangrass should be grown under the proper conditions (for example, it should be provided with enough water) and not grown in areas where it could be exposed to frost. Current research is focused on developing new strains of sudangrass with low hydrocyanic acid content.