Ravenna Grass

Tripidium Ravennae

Class A Noxious Weed

This plant is new to the state and has been designated a Class A Noxious Weed by the New Mexico Department of Agriculture.
Read more >>>

Riparian Threat

This plant is known to invade riparian areas or otherwise damage the health and abundance of our water resources.
Read more >>>

Commercially Available

Despite being classified as a noxious weed, this plant is still widely sold in stores! Keep an eye out, and remember that it is illegal to plant and transport noxious weeds in the state of New Mexico.

QUICK FACTS

Originally introduced as an ornamental plant in the United States in the 1920s, Ravenna grass has become a noxious weed, crowding out native species, particularly in riparian and wetland areas. It spreads quickly via wind-dispersed seeds and root fragments, making it challenging to control.
Ravenna grass is a significant fire risk, particularly in areas where it forms dense stands. The dry, dead vegetation it leaves behind in the summer months can easily catch fire, exacerbating wildfire risks in riparian habitats.
This grass not only outcompetes native vegetation but also disrupts ecosystems by blocking water flow and harming infrastructure. Its extensive root system can damage concrete structures, such as sidewalks and parking lots.

1. Overview

family	Poaceae – grasses	origin	Eurasia, Northern Africa
life cycle	Perennial	other names	Elephant grass, Italian sugarcane, Plume grass, Giant cane, Hardy pampas grass.

Beware! You are likely to come across this fluffy grass for sale online or in local garden stores. Ravenna grass is a showy ornamental that seems harmless and has only recently been declared a noxious weed.

Ravenna grass was once the belle of the garden ball, admired for its towering plumes and enduring presence in American gardens since the 1920s. Native to the Mediterranean and Eurasia, this ornamental grass has since revealed a more sinister side. It has escaped cultivated areas and become a noxious weed in various parts of North America. Rapid growth and seed production allow it to outcompete native vegetation, posing challenges to local ecosystems. While it may have started as an easy-to-grow addition to gardens, Ravenna grass now plays the role of an unwelcome intruder in many landscapes.

History of Ravenna Grass

Ravenna grass was introduced to the United States in the early 1920s for ornamental purposes. It was imported from the Mediterranean and named after the town of Ravenna, Italy. Native to Eurasia and parts of Northern Africa, Ravenna grass can be found in China and India, as far west as Kazakhstan, and south to northern regions of Africa. Still a popular ornamental today, Ravenna grass has become invasive in Australia, the United States, and Japan. This grass stabilizes soil in its native range and has been used for the same in the United States. Ravenna grass was moved from the Saccharum genus to Tripidium in 2015. [2,3]

2. ID Guide

What does it look like?

Ravenna grass is a large perennial bunchgrass, similar to sugarcane, reaching 14 feet in height and 7 feet in diameter. It has large, flowering plumes that resemble other cane inflorescences. Long basal leaf clumps (tussocks) form at the base while leaved stems continue upward, culminating in a large plume. Similar species include pampas grass (Cortaderia selloana) and jubata grass (Cortaderia jubata). They are distinguished by sparser plumes of Ravenna grass, hairs on the leaf undersides, and a thick, white vein down the center of the blades. [1,2,4,5]

Having trouble identifying a weed? Contact your local conservation district or county extension agent.

Key Features

Plant: Tall, upright stems emerge from a fluffy tussock, grow 5 to 13 feet tall, and are about 0.4 inches wide. Stems may be reddish or other colors during flowering. There are yellow hairs on the lower stem segments, which disappear near the top of the stem. [4]
Roots: A dense and diffuse root system allows the grass to spread via rhizomes. [1,3]
Leaves: The basal leaves are long and slender, reaching lengths of 3 to 4 feet and widths of 0.5 to 1 inch. A distinctive white midvein contrasts with their medium gray-green color. The upper side of the leaves near the base is densely covered in long, fuzzy yellow hairs, which often conceal the upper surface of the blade base. On the flowering stems, the leaves are shorter and extend up to the base of the inflorescence. [4]
Flowers: Ravenna grass produces large, feathery flower heads in late summer to fall, forming airy, branched panicles that rise above the foliage. Plumes are 9.5-24 inches tall and 4-6 inches wide. The individual flowers are small and initially purplish-pink or lavender, fading to silvery white as they mature, with silky hairs that give the plumes a soft, fluffy texture. Flowers are wind-pollinated and form light, airy seeds that are dispersed by wind and water. [4]
Seeds: Each seed is attached to a delicate, silky tuft of hair, which helps with wind dispersal. The seeds are typically tan or light brown and have a slender, elongated shape. [4]

The Nature Conservancy , The Nature Conservancy, Bugwood.org

Plumes are 9.5-24 inches tall and 4-6 inches wide and initially purplish-pink or lavender, fading to silvery white as they mature.

The Nature Conservancy , The Nature Conservancy, Bugwood.org

The basal leaves are long and slender, reaching lengths of 3 to 4 feet and widths of 0.5 to 1 inch.

Giovanni Perico, inaturalist.org

Ravenna grass enters a dormant phase as temperatures drop, with foliage dying back.

mircogruppi, inaturalist.org

A distinctive white midvein contrasts with the medium gray-green color of the leaves.

avieinn, inaturalist

Tall, upright stems emerge from a fluffy tussock, grow 5 to 13 feet tall, and are about 0.4 inches wide.

rkluzco, inaturalist.org

Each seed is attached to a delicate, silky tuft of hair, which helps with wind dispersal.

3. Infestation Basics

“The species is being found with increasing frequency in recent years. It seems likely that the species will become problematic in marginal areas and grasslands in the near future.”

-M.A Vincent & R.L Gardner, 2016

Impacts

Where does it grow, and how does it spread?

Ravenna grass can be found anywhere with relatively moist soil. This includes wetlands, riparian zones, and irrigation ditches. It can also be found in drier areas such as roadsides, fields, or even rocky slopes. [3,4]

This grass spreads primarily by wind-dispersed seeds but can also replicate from root fragments, adding an extra layer of difficulty to the plant’s eradication. Often, it can be found growing in the same area as common reed and saltcedar, as well as other listed noxious weeds in New Mexico. [2,4]

Ravenna grass reproduces through an extensive network of rhizomatous roots as well as thousands of seeds. Root fragments can sprout new plants. Germination of seeds occurs relatively quickly, producing young shoots that may be palatable to livestock, but only in the plant’s very early stages. Ravenna grass enters a dormant phase as temperatures drop, causing its foliage to die back. The plant’s extensive root system allows it to survive through the winter, preparing for renewed growth in the spring. [5,6]

Key takeaway: Ravenna grass thrives in various environments with moist soil, spreads through wind-dispersed seeds and root fragments, and often coexists with other invasive species, such as common reed and saltcedar.

Why is it so invasive?

The dense basal clumps of Ravenna grass often crowd out native plant species. The grass is especially invasive in riparian areas that would otherwise have a diverse set of native species. [5]

While Ravenna grass crowds out desirable riparian species, it directly affects ecosystems by restricting water flow and facilitating the spread of wildfires into wet areas. The extensive root systems are strong enough to damage concrete structures, such as buildings and sidewalks. [5]

These plants are difficult to eradicate due to their vigorous regeneration from their roots. Mowing, burning, grazing, and other physical removal methods will be ineffective unless all roots are removed and destroyed, along with the above-ground growth. [2]

Key takeaway: Ravenna grass outcompetes native plants, especially in riparian areas, disrupting ecosystems by blocking water flow and promoting wildfires. It is difficult to eradicate due to its extensive root system.

Common risk factors for invasion

Disturbed Soils: While Ravenna grass can establish itself in undisturbed areas, soil disturbance often creates ideal conditions for invasion. Soil disruption weakens existing vegetation, allowing the weed to become established. Minimizing unnecessary soil disturbance can help reduce the risk of invasion.
Moisture Availability: Ravenna grass generally requires adequate moisture to establish and spread, making irrigated lands and areas with consistent rainfall particularly vulnerable. Seeds can also spread by water, allowing for ideal germination conditions along wet streambanks.
Riparian Areas: Seeds are easily carried by streams and may be subsequently deposited on river terraces. Growing near streams or rivers allows the weed’s roots to easily reach the water table.

Ecosystem Health

Ravenna grass displaces native plants, resulting in a substantial loss of biodiversity. This may reduce forage availability and habitat for songbirds and waterfowl. The dense thickets this weed creates can provide a habitat for rodents while excluding desirable wetland creatures. [2,5]

Infrastructure Issues

Ravenna grass’s roots are capable of lifting concrete as they grow. This ability allows the plant to undermine the stability of areas such as parking lots, sidewalks, and driveways, leading to costly repairs and maintenance. [5,6]

Fire Hazard

Older stands of Ravenna grass can leave behind large amounts of dry, dead vegetation throughout the hot summer months. The dry foliage can quickly catch fire, which becomes more likely as it forms a monoculture. Because of its riparian proximity, this species can bring wildfires to riparian habitats that would otherwise be less susceptible to devastating fires. [6]

4. Management Strategies

When managing Ravenna grass, early detection and control are crucial for effective management. The perennial grass spreads rapidly through seeds and rhizomes, often invading riparian areas. Mechanical control, such as mowing before flowering, can reduce seed production but may not wholly eradicate it because of prolific regeneration from roots. Herbicides are most effective during active growth, although timing is crucial for optimal results. Preventing the spread of weeds should involve cleaning equipment to avoid transporting seeds and properly disposing of plant material. Long-term management should combine mechanical, chemical, and cultural methods, promoting competitive native vegetation to suppress its growth.

DO’s

For small infestations, manually remove plants by digging up the entire root system. Ensure all root fragments are extracted to prevent regrowth.
After removal, collect all plant material, especially seed heads, and dispose of them securely by incineration or in sealed bags to prevent seed dispersal.
Replant areas with native species to outcompete any remaining Ravenna grass and restore ecological balance.

DON’Ts

Avoid using fire or grazing animals as control methods. These can stimulate regrowth and don’t effectively eliminate the plant.
When moving soil or plant material, ensure it’s free from Ravenna grass seeds or roots to prevent spreading to new areas.
Burn or graze: Simply cutting or mowing Ravenna grass is insufficient. These methods don’t address the root system, leading to regrowth.

** The following information is provided courtesy of the UC Weed Research and Information Center. The Taos Soil and Water Conservation District does not endorse the use of any particular product, brand, or application thereof. **

Managing Ravenna grass without chemicals involves repeated mowing or cutting before seed set to deplete root reserves and prevent spread. Additionally, digging out small infestations, including the entire root system, combined with mulching or planting competitive native species, can help suppress regrowth.

Hand-pulling

Manual removal of individual plants is possible, provided all root and rhizome fragments are also removed. The National Park Service staff and volunteers report the removal of over 25,000 plants in the Grand Canyon. It is now considered rare throughout the canyon. Control techniques are very similar to those published for Cortaderia species.

Because of the proximity to riparian areas, there are no cultural control options that have been reported.

No biological control agents are available for ravennagrass control.

The following specific use information is based on published papers and reports by researchers and land managers. Other trade names may be available, and other compounds also are labeled for this weed. Directions for use may vary between brands; see label before use. Herbicides are listed by mode of action and then alphabetically. The order of herbicide listing is not reflective of the order of efficacy or preference.

Glyphosate

Roundup, Accord XRT II, and others

Rate: Most control efforts use spot treatments of a 5% glyphosate v/v solution of Rodeo or Aquamaster (2.5% a.e.).

Timing: Postemergence, to plants that are fully mature, but before flowers produce viable seeds. This is likely during the early summer months.

Remarks: Glyphosate is a nonselective herbicide with no soil activity. It has proven to be the most effective chemical control option for Ravenna grass. There have also been reports that a 5% glyphosate solution mixed with 1% imazapyr (Habitat) will give very effective control.

5. Citations

[1] Anderson, Lars W., et al. Weed Control in Natural Areas in the Western United States. Davis, California, University Of California Weed Research And Information Center, 2013.

[2] Robinson, Kassidy. “Ravenna Grass (Tripidium Ravennae) – Long Island Invasive Species Management Area (LIISMA).” Long Island Invasive Species Management Area (LIISMA), 22 Nov. 2023, liisma.org/ravenna-grass-tripidium-ravennae/. Accessed 7 Mar. 2025.

[3] Vincent, M.A. and R.L. Gardner. 2016. Spread of the invasive Ravenna grass (Tripidium ravennae, Poaceae) in Ohio. Phytoneuron 2016-78: 1–9. Published 29 November 2016. ISSN 2153 733X

[4] Washington State Noxious Weed Control Board. “Ravenna Grass.” Www.nwcb.wa.gov, www.nwcb.wa.gov/weeds/ravenna-grass. Accessed 7 Mar. 2025.

[5] Franklin County Noxious Weed Control Board. “Ravenna Grass.” Franklin County Noxious Weed Control Board, 2019, fcweedboard.com/ravenna-grass.

[6] Chimera, Chuck. “Saccharum Ravennae Risk Assessment.” Hawaii Invasive Species Council, Coordinating Group on Alien Pest Species, 8 Feb. 2018. https://plantpono.org/wp-content/uploads/Saccharum-ravennae.pdf

[7] Nozoye, T., et al. (2017). Bioenergy grass [Erianthus ravennae (L.) Beauv.] secretes two members of mugineic acid family phytosiderophores which involved in their tolerance to Fe deficiency. Soil Science and Plant Nutrition, 63(6), 543–552. https://doi.org/10.1080/00380768.2017.1394168

oscarbraun, inaturalist.org

Alli, inaturalsit.org

Fun Facts

There is growing interest in using non-food crops, such as Ravenna grass, for biofuel production, as they help reduce CO2 emissions without competing with food crops. Closely related to sugar cane, Ravenna grass exhibits a relatively high sugar content, high biomass yield, and tolerance to environmental stress. Ravenna grass shows promise as a biomass energy crop. Breeding efforts are needed to improve traits such as increased biomass, pest resistance, and drought tolerance. [7]