Ventenata

Ventenata is a winter annual grass in the Poaceae family. Seeds may germinate in early spring or late fall. It produces slender, 6 to 28 inch long stems. Stems and underside of leaves may have small hairs or may be glabrous. Leaves are narrow (1 to 3 mm wide) and 2 to 7 cm long. Leaf blades are usually flat at the base and rolled or folded toward the tips. Ligules are membranous and up to 1 cm long. Stem nodes are reddish-black to black and glabrous. Ventenata flowers from mid-spring to early summer. Inflorescences are wiry panicles that may be up to 8 inches long. These panicles are composed of clusters of spikelets containing 3 florets with at least one twisted awn. Seeds are formed in awns that are around ¾ to 1 inch long. Seeds are usually viable for 2 years. Ventenata has a shallow, fibrous root system.

Ventenata plants contain high amounts of silica which slows the decomposition of the dead plant material and creates dense patches of thatch or duff.

Ventenata is native to Eurasia and Northern Africa. It was first found in North America in the 1950s. The dense thatch layers left behind each growing season feed hotter and more frequent fires that native vegetation, like sagebrush, can withstand. Ventenata is not currently found in Teton County. It is found in rangeland systems in other areas of the West.

Prevention strategies and cultural control strategies should be utilized as much as possible. Use weed free forage and gravel, and clean construction equipment before moving to a new location. Clean recreational gear, clothing, and pets after recreating to prevent spreading this and other species to new areas.

There are not currently any biological control agents available for ventenata.

Hand pulling of small infestations of ventenata, prior to seed maturation, is highly effective. Shallow cultivation including tilling or hoeing is also effective if conducted immediately after germination and prior to flower production. Mowing is not recommended. Grazing is also not frequently effective due to the high silica content of the plant materials.

Large infestations can be controlled with herbicides. With the exception of glyphosate, herbicides should be applied preemergence to prevent germination. Glyphosate is only effective on cheatgrass prior to seed production. Application timing for preemergent herbicides varies based on moisture or rainfall requirements, but most can be applied in August. Read the label before using any herbicide and for application timing details. Contact TCWP if you have any questions about application rates or how to use an herbicide.

• MontGuide: Ventenata. (2025) Harvey, A. and Mangold, J. Department of Land Resources and Environmental Sciences. Montana State University Extension.
• Weed Report: North African Wiregrass (2013). DiTomaso, J.M., Kyser, G.B. et al. Weed Control in Natural Areas in the Western United States. Weed Research and Information Center. University of California.
• Ventenata dubia, Ventenata. (2022) Innes, R.J. Fire Effects Information System. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory.
• Ventenata. Washington State Noxious Weed Control Board.