United States Department of Agriculture

Field Guide for Managing

Fountain Grass in the Southwest

Forest 

Service

Southwestern

Region TP-R3-16-27 Revised June 2017
Cover Photos

Top right: NPS

Bottom right: John M. Randall, The Nature Conservancy, Bugwood.org 

Left: Forest and Kim Starr, Starr Environmental, Bugwood.org

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Fountain grass (Pennisetum setaceum; synonyms: P. ruppelii, Phlaris setacea)

Grass family (Poaceae); Bromeae tribe

Fountain grass is currently expanding its range in the

southwestern U.S. and has been reported as invasive in

California, Nevada, and Arizona. This field guide serves as 

the U.S. Forest Service’s recommendations for

management of fountain grass in forests, woodlands, and

rangelands associated with its Southwestern Region. The

Southwestern Region covers Arizona and New Mexico, 

which together have 11 national forests. The Region also 

administers 4 national grasslands located in northeastern 

New Mexico, western Oklahoma, and the Texas panhandle.

Description

Fountain grass (synonyms: crimson fountain grass, purple

fountain grass, fountaingrass) is a warm climate, perennial

bunchgrass native to northern Africa and western Asia.It 

has been widely planted in urban settings as a landscape

ornamental. Over time, it has escaped horticultural areas

and is now found in many arid land habitats.

Growth Characteristics

• Tufted perennial bunchgrass; warm climate; uses C4 

pathway that fixes CO2 into a four-carbon compound 

(C4) rather than a three-carbon compound (C3); may 

become dormant in the winter; individual plants may

live 20 years or more.

• Has several upright stems growing from a densely 

clumped tussock; 2–4.5 feet tall.

• Leaves are bright green or purplish; these may turn 

reddish or tan with colder temperatures. Blades are

long, slender, and arching (8–25 inches); sheath 

margin has stiff white hairs.

• Has a showy purplish, bottlebrush-like panicle (6–15 

inches); spikelets have 1-inch long bristles.

• Roots are fibrous and grow to 1 foot deep; forms 

mycorrhizal associations; no rhizomes.

• Reproduces solely by seed, though it may be 

intentionally propagated through division; seeds

germinate in late spring after maturing forseveral

months; seeds viable 6–7 years.

Ecology

Impacts/Threats

While attractive in a contained setting, fountain grass can 

aggressively spread in an open, arid environment under full

sun and rapidly out-compete native herbaceousspecies. 

When dry, it is highly flammable. Its presence greatly 

increases the fire potential and often causes a change in the 

fire pattern in areas it invades. Other impacts include 

reduced available forage, diminished diversity of flora and 

fauna, and decreased wildlife habitat.

Site/Distribution

Warm, arid landscapes including canyons, desert,

grassland, and rangeland; roadsides; arroyos and washes. It 

is found in similar habitats as buffelgrass; however, 

fountain grassis more cold tolerant and is able to occupy a 

wider elevational range. Fountain grass prefers mild 

winters, summer rain, and median annual precipitation of 

less than 50 inches. It does not tolerate freezing 

temperatures or saline soils.

Spread

Ornamental plantings serve as the primary way fountain

grass can be spread. Even varieties of fountain grass 

mistakenly sold by nurseries as being infertile can still

become pollinated by fertile varieties or closely related

plant species and develop viable seed. Seeds have bristles

that may become tangled in animal fur; they may be

carried by wind, water, birds, or by small rodents. Seeds

may also adhere to clothing or be carried for long distances

on undercarriages of vehicles and road maintenance

equipment.

Invasive Features

Fountain grass is highly adaptable to many environments

(high plasticity). Growth characteristics and reproduction

may change according to the altitude at which it is 

growing, and its physiology may adjust in response to

physical features of the landscape. For example, its rate of 

photosynthesis increases at higher altitudes. Repeated

wildfire favors fountain grass.
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Management

Prolific production of long-lived seed hinders control 

efforts once fountain grass is established. Control 

measures should focus on prevention and proactive 

management. Consider the following actions when 

planning a management approach:

• Landscape alternatives should be promoted to 

landowners (especially in housing developments near

open rangelands) to minimize new introductions of 

fountain grass.

• Healthy plant communities should be maintained to 

limit infestations of fountain grass.

• Check hay, straw, and mulch for presence of weed

seed before using them in weed-free areas; certified

weed-free hay or pellets should be fed to horses used 

in the back country.

• Detect and eradicate new populations of fountain 

grass as early as possible. Keep annual records of 

reported infestations.

• Combine mechanical, cultural, biological, and 

chemical methods for most effective control.

• Implement monitoring and a follow-up treatment 

plan for missed plants or seedlings.

Table 1 summarizes some management options for the 

most common situations involving fountain grass. Further 

details on these management options are explained below. 

Choice of control method for fountain grass depends on

the current land use and site conditions; accessibility,

terrain, and microclimate; extent and density of 

infestation; and non-target flora and fauna present. Other 

considerations include treatment effectiveness, cost, and 

the number of years needed to achieve control. More than 

one control method may be needed for each site.

Physical Control

Manual Methods

Hand-pulling, grubbing, and hoeing buffelgrass are 

effective (but demanding) methods for control. Removal is

easiest when the soil is moist, temperatures are cool, and 

plants are in their early life stage. Manual removal of 

seedlings and plants every 1–2 months has been used with 

some success in Hawaii Volcanoes National Park. A pick, 

mattock, Pulaski, or shovel may be required for plants with 

a tussock diameter greater than 4–6 inches. Remove as 

much of the root as possible. Debris—especially debris 

with inflorescences—should be bagged and removed from 

the site to preventspread. Manual methods may be more 

effective when combined with herbicide application.

Mechanical Methods

Mowing or tillage with a plow or disc may be used when 

fountain grass infestations are accessible, level, and free of 

large rocks. However, mechanical methods are normally

not feasible due to the steep, rocky locations the plant

frequently inhabits. Cutting with a weed trimmer may be 

an alternative for areas where mower use is not feasible. 

Inflorescences should be burned or collected, bagged, and 

removed to prevent seed bank contribution. Where 

possible, mechanical methods may be combined with an 

herbicide application to increase control effectiveness. 

Whatever method is chosen, anticipate that it may need to 

be repeated to reach an acceptable level of control.

Prescribed Fire

Burning is not recommended, except as a means to

manage debris. Fountain grass rapidly regrows following 

fire, which often leads to an increase in its dominance.

Cultural Control

Seed and materials used for mulch, forage, or fill should 

be certified to be weed-free; pellets may be used for horses 

in backcountry areas. Land managers, the local public, and 

road crews should be educated in identification of invasive 

species so they can help report all suspected infestations. 

Vehicles, humans, and domestic animals should be 

discouraged from traveling through infested areas; and a 

program to check and remove seeds from vehicles, 

clothing, and domestic animalsshould be implemented to 

help stop dispersal. Since this species is currently 

promoted as an ornamental, coordination with local 

nurseries to distribute information about this plant’s 

invasive potential may be warranted.
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Table 1. Management options*

Site Physical Control Cultural Control Biological Control Chemical Control

Roadsides Mow or grade repeatedly

during growth season to 

suppress seed production.

Assemble volunteer

groups to hand pull.

Use seed, mulch, and fill materials 

certified to be weed-free.

Avoid planting as an ornamental

near open range areas.

Implement requirements for vehicle 

operations and for reporting 

infestations along roads.

No classical biological

control agents have been

approved for use by the

USDA.

Use truck spraying

equipment. Wash underneath 

to prevent spread.

Rangeland Hand pull or use a weed 

trimmer; repeat every 1–2 

months for at least 4 

years. Bag debris, 

especially debris with

inflorescences.

Use seed and forage hay certified to 

be weed-free; use pellets for horses 

in backcountry areas.

After moving livestock or vehicles

through an infested area, inspect

and remove any seeds from 

animals, clothing, and vehicles

before exiting the infested area.

Early spring grazing can

temporarily reduce density, 

fuel loads, and risk of 

wildfire. However, plants 

become less palatable as 

they mature which may

increase preference for nontarget plants.

Use systemic, pre or postemergent herbicides.

Use aerial or ground

broadcast sprayers or 

backpack sprayers for areas 

difficult to access.

Wilderness 

and other

natural

areas

Manual methods such as 

hoeing or hand pulling

may be needed to protect

other resources.

Use seed and forage hay certified to 

be weed-free; use pellets for horses 

in backcountry areas.

Post signs warning visitorsto

remove seeds.

Limit public access in severely 

infested sites.

Reseed with desirable perennial

plants to suppress fountain grass.

Same as above Use backpack sprayer for 

small stands. Broadcast

spraying by ground or aerial

methods may be used on 

thicker stands, if allowed.

* Choice of a particular management option must be in compliance with existing regulations for the land resource.

Biological Control

Grazing

Except when young, fountain grass is not highly palatable

nor is it very nutritious as a forage grass. It may be grazed

intensively by sheep or cattle in early spring while shoots

are tender and succulent. However, livestock will usually 

graze other desirable species first and avoid fountain grass.

Classical Biological Control

No classical biocontrol agents (insects, pathogens, etc.) 

have been approved by the USDA for use on fountain 

grass. Development of an acceptable biocontrol agent is 

hampered by the potential to impact related forage and 

crop species,such as pearl millet and sugar cane.

Chemical Control

Herbicides listed in table 2 will effectively control 

fountain grass when properly applied, although some may

negatively impact non-targetspecies. Aquatically

approved herbicide formulations and surfactants must be

used in or near water. Each herbicide product has unique

requirements and restrictions; therefore, it is important to

read the label carefully and to follow all instructions and 

guidelines when mixing and applying the chemical.

Herbicide Application

Precautionsshould be taken to protect desirable non-target 

plants (particularly woody species) from both direct spray 

and spray drift of glyphosate and especially imazapyr. 

Also, imazapyr may kill or injure non-target plants
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Table 2. Herbicide recommendations

Common

Chemical

Name (active 

ingredient)

Product

Example1

Broadcast 

Treatment 

(rate per 

acre)

Spot 

Treatment 

(spray 

solution) 2

Time of

Application Remarks

Glyphosate Roundup Pro

Rodeo

Accord

0.5–1 pint 5–8% + 0.5%

nonionic surfactant

Any growth stage

when green and

actively growing.

Nonselective amino acid inhibitor;

will affect most vegetation,

including forbs and woody species;

quickly inactivated in the soil.

Foliar application only. Completely

spray all green leaves; follow-up by 

spraying seedlingsannually.

Imazapyr Habitat

Arsenal

[others 

available]

2–3 pints 1–3% When fountain 

grass is actively

growing as 

indicated by bright

green and glossy 

leaves.

Imazapyr is a nonselective amino 

acid inhibitor. In addition to spray 

drift, non-target plants may also be 

killed or injured by imazapyr 

through runoff, residue movement 

in soil, or root exudates from 

treated plants.

For perennial grasses, imazapyr

is best used as a post-emergent

control, which requires the use of 

a 0.25 nonionic surfactant or 1 

percent methylated seed oil

(MSO); follow label instructions. 

Herbicidal activity may be slow. 

Allow two full growing seasons 

before follow-up treatment.

Hexazinone Velpar DF 1.5 lbs + 25 

gallons water

(minimum)

2.66 lbs + 1 gallon 

water

Anytime,

preferably before

a rain event.

Not for use near waterways or 

desirable woody species. High 

soil mobility; groundwater 

contamination potential.

Contact and residual control; use 

lower rate on coarse-textured soil

(sand to sandy loam); use higher

rate with fine-textured soils (clay 

loam to clay) or soils high in

organic matter.

Fluazifop-p-butyl Fusilade 2000

Fusilade DX

1–1.5 pints 0.5% + 0.25%

nonionic surfactant

In spring after 

emergence but

before seed head

is detectable.

Attacks meristematic tissue of 

annual and perennial grasses. 

Does not affect broad-leaved

plants.

1 Trade names for products are provided for example purposes only, and other products with the same active ingredient(s) may be available. Individual 

product labels should be examined for specific information and appropriate use with fountain grass.

2 Spray solution is the herbicide/water ratio in a spray mix that may be used for spot treatment with backpack or hand-held sprayers. The amount of product 

applied during an annual growing season must not exceed the maximum application rate per acre as specified by the product label – refer to the product 

label for the site type and application.
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through runoff, residue movement in soil, or root 

exudation from treated plants. Therefore, imazapyr should 

not be used in residential, urban, or wildland-urban 

interface (WUI) areas where ornamental vegetation or turf 

grass may be affected. To protect desirable trees or shrubs, 

do not apply imazapyr within twice the drip line (canopy 

edge) distance. For desirable cacti, imazapyr should not be 

applied closer than at least twice the extent of their lateral 

root system. Fluazifop-p-butyl will kill annual and 

perennial grasses but does not harm broad-leaved plants.

When spraying fountain grass with a foliar active 

herbicide (such as glyphosate, imazapyr, or fluazifop-pbutyl), the foliage should be at least 50 percent green;

however, better control may be obtained when plants are 

more than 80 percent green. Fountain grass mortality rates 

of at least 90 percent have been attained by the Lake Mead 

Exotic Plant Management Team of the U.S. National Park 

Service by using annual spot treatments of glyphosate on 

actively growing plants. Hexazinone is active mainly 

through the roots so this herbicide should be applied 

before anticipated rainfall.

A backpack or hand-held sprayer should be used for small, 

infestations. With foliarly-applied herbicides, enough 

spray should be used to moisten the leaves, but not so 

much that spray drips off the plant. Adding a blue or red 

dye to the solution will aid in identifying treated plants. 

For areas with larger, denser infestations, it may be more 

practical to use an ATV or UTV sprayer or a conventional 

boom sprayer that is pulled or mounted to a truck or 

tractor. Any equipment used to spray herbicide should be 

calibrated.

Integrated Control Methods

The following combinations of control methods should be 

considered to contain and reduce fountain grass 

infestations:

• Manual removal-herbicide – Coordinate removal 

efforts between landowners or organizations to handpull or dig up fountain grass plants, especially

targeting isolated populations and sporadically

occurring plants that could become a future source of

invasion. Monitor treated areas and follow with 

herbicide applications as needed to maximize

control.

• Herbicide-mechanical removal – Apply herbicide 

to actively growing plants; allow 2 weeks for 

herbicide to translocate to roots; then mow or cut 

with a weed trimmer. An alternative is to mow first, 

allow plants to regrow to a height of 10 inches and 

apply herbicide. Another option is to till, followed by 

an herbicide application to minimize germination of

remaining seed.

Management Strategies

Areas slated for treatment should be prioritized, and a 

combination of control methods should be considered 

when attacking fountain grass. Treatment priority should 

be assigned to small or sporadic infestations found on 

otherwise healthy sites, followed by treatment of more 

established infestations. Satellite and small, isolated 

populations should be eradicated, while larger areas of 

infestation should be contained and gradually reduced 

over time, starting around the perimeter. Initial treatment

of large infestations should try to eliminate as many live 

plants and disrupt as much seed production as possible. 

Secondary treatments should include monitoring and 

additional control measures (such as spot spraying) to

eliminate seedlings and increase competition from

desirable perennial plants.

Fountain grass seed is viable for 6 or more years in the

seed bank; therefore, a short-term strategy for managing 

fountain grass is unlikely to succeed. Since it is ordinarily 

useless to treat an area only one time without retreatment,

sufficient resources must be allocated for the area where

control is attempted. After initial treatment, it is important

that resources are also available to respray or retreat the

treated area as necessary. Previously treated areas should

always be monitored annually to detect regrowth of 

treated plants and newly emerged seedlings. Follow-up 

treatment should be anticipated and planned as part of a 

complete restoration program. Failure to perform followup monitoring and adapt control methods as needed could 

result in a return to pretreatment levels of invasion.
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Adaptive Management

Current experience and research suggest that there will not 

be one overarching process or set of tactics for controlling

fountain grass consistently. Therefore, realistic goals and

objectives should be established to manage fountain grass 

infestations occurring broadly across a given landscape. To 

improve long-term success, consider using an adaptive 

management approach with overall goals of reducing fires

and maintaining or restoring desirable plant communities. 

The stepwise process for adaptive management involves 

1. Assessment of the overall weed problem,

2. Establishing management goals and objectives,

3. Implementation of control strategies and measures,

4. Monitoring effectiveness of management actions,

5. Evaluating actual outcomes in relation to expected 

results, and 

6. Adjusting practices as necessary.

Steps of this process should be repeated in sequence as

part of a continuous learning cycle that improves

management planning and strategy by learning from the 

outcomes of previous management actions. In general, an 

adaptive management approach is considered to be 

successful if

1. Stakeholders are actively involved and remain 

committed to the process,

2. Monitoring and assessment are used to adjust and

improve management decisions, and

3. Management goals and/or objectives for the 

resource are being achieved.

References and Further

Information

Arizona Invasive Species Advisory Council. 2008.

Arizona Invasive Species Management Plan.

Available at http://www.azgovernor.gov/ais/ 

Documents/AISMP2008.pdf (accessed July 2010).

Arizona Sonora Desert Museum Invaders Program. Project 

Species: Fountaingrass. Available at http://www.

desertmuseum.org/invaders/invaders_fountaingrass. 

php (accessed July 2010).

Benton, N. 2005. Weeds Gone Wild Factsheet: Fountain 

grass. The Nature Conservancy. Available at

http://www.nps.gov/plants/alien/fact/pese1.htm

(accessed July 2010).

Castillo, J.M. 1997. Control of Pennisetum setaceum in 

Native Hawaiian Dry Upland Ecosystems.Available

at http://www.hawaiiforest.org/reports/03-5Thesis10.

PDF (accessed July 2010).

Deuser, C. and R. Tietjan. 2009. Keeping Fountaingrass

Out of the Mojave Desert (poster). NPS Lake Mead

Exotic Plant Management Team. Lake Mead Science

Symp., Jan. 13–14, 2009. Available at

http://www.lakemeadsymposium.org/pdf/posters/ 

poster_R1.pdf (accessed July 2010).

Deuser, Curt. 2010. Email communication July 15, 2010, 

re: herbicide rates used by Lake Mead Exotic Plant 

Mgmt Team (Nevada). Curt_deuser@nps.gov.

Encycloweedia Datasheets by CA Dept. Food and Agric.

Available at http://www.cdfa.ca.gov/phpps/ipc/

weedinfo/pennisetum.htm (accessed July 2010).

Fenner, Patti. 2008. Effects of Invasive Plants on Public 

Land Management of Pinyon-Juniper Woodlands of

Arizona. In G.J Gottfried et al. (compilers). Ecology, 

Management, andRestoration of Piñon-Juniper and 

Ponderosa PineEcosystems. RMRS-P-51. Available 

at http://www.fs.fed.us/rm/pubs/rmrs_p051/rmrs_

p051_113_120.pdf (accessed July 2010)
7

Halvorson, W.L. and P. Guertin. 2003. USGS Weeds in the 

West: Pennisetum setaceum. Available at

http://sdrsnet.srnr.arizona.edu/data/sdrs/ww/docs/pen

nseta.pdf (accessed July 2010).

Lovich, J. 2000. Fountain grass (Pennisetum setaceum). In 

Bossard, C.C., et al. (Eds.) Invasive Plants of 

California’s Wildlands. Univ. California Press. 

Berkley, CA. Available at http://www.cal-ipc.org/ip/ 

management/ipcw/online.php (accessed July 2010)

Moody, M.E. and R.N. Mack. 1988. Controlling Spread of 

Plant Invasions: The Importance of Nascent Foci. J. 

Applied Ecology 25(3):1009-1021.

Northam, E. and W. Meyer et al. 2009. Non-Native 

Invasive Plants of Arizona. Conservation Districts 

and RC&D Areas of Arizona and the University of 

Arizona Cooperative Extension. Publication AZ 

1482. Available at http://cals.arizona.edu/pubs/ 

natresources/az1482.pdf (accessed July 2010).

Plagen, M.J. (ed.) Online: Nature Study in theSonoran

Desert: A Guide to the Flora and Fauna of Arizona, 

U.S.A. and Sonora, Mexico. Available at

http://www. arizonensis.org (accessed July 2010)

Suggested Web Sites

For information about calibrating spray equipment: 

NMSU Cooperative Extension Service Guide A-613, 

Sprayer Calibration. Available at 

http://aces.nmsu.edu/pubs/_circulars/CR_597.pdf
For more information or

other field guides, contact:

USDA Forest Service 

Southwestern Region

Forest Health

333 Broadway Blvd., SE 

Albuquerque, NM 87102

Or visit the Southwestern Region’s 

website for invasive species:

http://www.fs.usda.gov/goto/r3/invasivespecies

The use of trade or firm names in this publication is for reader 

information only and does not imply endorsement of any 

product or service by the U.S. Department of Agriculture. 

Recommendations made here for 

pesticide use are not obligatory, 

nor do they imply that discussed

uses have been registered. All

uses of pesticides must be

registered by appropriate State 

and/or Federal agencies before

they can be applied.

CAUTION: Pesticides can be 

injurious to humans, domestic

animals, desirable plants, and fish or other wildlife—if they 

are not handled or applied properly. Use all pesticides

carefully and lawfully. Follow recommended practices for the 

disposal of surplus pesticides and pesticide containers.