1

This publication is part of a series that provides an overview of the presence of invasive plant species monitored on 

an extensive systematic network of plots measured by the Forest Inventory and Analysis (FIA) program of the U.S. 

Forest Service, Northern Research Station (NRS). Each research note in this series features one of the invasive 

plants monitored on forested plots by FIA in the 24 states of the Midwestern and Northeastern United States.

Background and Characteristics

Reed canarygrass (Phalaris arundinacea) is a cool-season perennial grass 

that can survive in a wide range of environmental conditions. It is native 

to Eurasia and North America; however over the past 100 years, several 

cultivars have been bred for forage, bioenergy, ornamental use, and 

restoration (Lavergne and Molofsky 2004). Distinguishing between native 

and nonnative strains is very difficult. It is believed that most colonies in the 

Midwest are of Eurasian origin (Czarapata 2005).

Reed canarygrass has optimal growth in full sun but is able to tolerate some 

shade. Where it is found, this species often forms dense colonies (Fig. 1) 

that reduce wildlife quality and restrict the growth of other species. Despite 

its ability to quickly invade an area, this aggressive invader is still planted for 

a wide variety of uses due to its vigor, low cost, and widespread availability 

(Kurtz 2013).

The latitudinal range where reed canarygrass is most abundant in Europe 

coincides with its distribution in the American Midwest. Since reed 

canarygrass is a cool-season grass, it is predicted that its distribution will shift 

northward with climate change (Kurtz 2010, Laverge and Molofsky 2004).

Description

Growth: tall (can reach >6 feet), rhizomatous grass with hairless stems and 

flat, tapering leaf blades which are rough in texture (both surfaces).

Reproduction: seed and rhizomes; plants bloom in the spring (Fig. 2).

Habitat: most prevalent in wet areas but tolerates a wide range of 

conditions; occurring in pastures, forests, fields, and along roadways.

Growth conditions: low drought tolerance (30 to 65 inches of annual 

precipitation), high anaerobic tolerance (can withstand continuous inundation 

for 60 to 70 days), moderate tolerance of saline and calcareous soils, 

intolerant of coarse soils, 14 inch minimum rooting depth, pH of 5.5 to 8.0, 

≥120 frost free days, and hardy to -38 °F.

Control: various mechanical and chemical methods including using both in 

tandem (such as tilling and herbicide application); it is difficult to eradicate 

established colonies due to large seedbanks (Czarapata 2005, NRCS 2014).

Range

Reed canarygrass is currently found in 43 states, 10 Canadian provinces 

(not present in Labrador), two territories, Saint Pierre, and Miquelon (Fig. 3) 

(NRCS 2014).

United States Department of Agriculture

An Assessment of Reed Canarygrass in Northern U.S. Forests Research Note NRS-200

Forest Service

Northern Research Station

Figure 1.—Reed canarygrass 

infestation. (Jamie Nielsen, University of 

Alaska Fairbanks, Cooperative Extension 

Service, Bugwood.org).

Figure 2.—Reed canarygrass in 

flower. (Tom Heutte, U.S. Forest Service, 

Bugwood.org) 

Figure 3.—Reed canarygrass presence, 

U.S. and Canada. (NRCS 2014)
2

FIA crews visited 7,579 forested Phase 2 (P2) Invasive plots across the NRS region between 2008 and 2012. Fortythree invasive plant species (IPS)1

 and one undifferentiated genus (nonnative bush honeysuckles)2 were monitored. 

On each of these plots, which were measured in the summer, various attributes were collected including the 

occurrence and coverage of IPS as well as the standard forest variables measured on P2 plots (e.g., tree diameter, 

height). Overall, 49.5 percent of forested plots had one or more of the monitored invasives present.

Reed canarygrass was the third most commonly observed invasive plant species, after multiflora rose and garlic 

mustard. This invasive graminoid was found on 611 plots (8 percent) and occurred in 21 of the 24 states (Fig. 4). It 

was not found on plots in Maryland, South Dakota, and Rhode Island. However, according to the Plants Database 

(NRCS 2014), reed canarygrass occurs in all 24 NRS states. Iowa had the highest percentage of plots with reed 

canarygrass (45 percent). Additional information about the species monitored and county level occurrence maps for 

the NRS region from 2005 through 2010 can be found in Kurtz (2013).

Reed Canarygrass Presence on Phase 2 Invasive Plots

Figure 4.—Inventory reporting area showing percent of Phase 2 

Invasive plots with reed canarygrass, 2008-2012.

Reed canarygrass. (Jamie Nielsen, 

University of Alaska Fairbanks, 

Cooperative Extension Service, 

Bugwood.org)

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Amur honeysuckle (Lonicera maackii), autumn olive (Elaeagnus umbellata), black locust (Robinia pseudoacacia), 

Bohemian knotweed (Polygonum xbohemicum), bull thistle (Cirsium vulgare), Canada thistle (Cirsium arvense), 

Chinaberry (Melia azedarach), common barberry (Berberis vulgaris), common buckthorn (Rhamnus cathartica), common 

reed (Phragmites australis), creeping jenny (Lysimachia nummularia), dames rocket (Hesperis matronalis), English ivy 

(Hedera helix), European cranberrybush (Viburnum opulus), European privet (Ligustrum vulgare), European swallowwort (Cynanchum rossicum), garlic mustard (Alliaria petiolata), giant knotweed (Polygonum sachalinense), glossy 

buckthorn (Frangula alnus), Japanese barberry (Berberis thunbergii), Japanese honeysuckle (Lonicera japonica), 

Japanese knotweed (Polygonum cuspidatum), Japanese meadowsweet (Spiraea japonica), leafy spurge (Euphorbia 

esula), Louise’s swallow-wort (Cynanchum louiseae), Morrow’s honeysuckle (Lonicera morrowii), multiflora rose (Rosa 

multiflora), Nepalese browntop (Microstegium vimineum), nonnative bush honeysuckle (Lonicera spp.), Norway maple 

(Acer platanoides), Oriental bittersweet (Celastrus orbiculatus), princesstree (Paulownia tomentosa), punktree (Melaleuca 

quinquenervia), purple loosestrife (Lythrum salicaria), reed canarygrass (Phalaris arundinacea), Russian olive (Elaeagnus 

angustifolia), saltcedar (Tamarix ramosissima), showy fly honeysuckle (Lonicera xbella), Siberian elm (Ulmus pumila), 

silktree (Albizia julibrissin), spotted knapweed (Centaurea stoebe L. ssp. micranthos), tallow tree (Triadica sebifera), 

Tatarian honeysuckle (Lonicera tatarica), tree of heaven (Ailanthus altissima)

2

The 43 IPS and one undifferentiated genus (nonnative bush honeysuckles) are hereafter referred to as “invasive 

species”, “invasive plants”, “invasives”, or “IPS”.
3

The percentage cover of reed canarygrass 

is shown in Figures 5 and 6, Figure 5 

illustrates cover at the state level; Figure 

6 focuses on the plot level. It is important 

to use caution when looking at overall 

state averages (Fig. 5) as states with a 

small number of occurrences are driven 

by a low number of plots. For states with 

few observances (e.g., Massachusetts 

and New Hampshire), Figure 6 is more 

informative since individual plot values 

can be assessed. These maps, along with 

Figure 4, reveal important information 

related to the presence and abundance of 

reed canarygrass in the NRS region. As can 

be seen in these maps, the occurrence of 

reed canarygrass is greatest in the north 

central part of this region. Over time these 

maps will allow us to assess changes in 

abundance and spread.

Reed Canarygrass Cover on Phase 2 Invasive Plots

3

Figure 5.—Average percent cover3 of reed canarygrass on 

Phase 2 Invasive plots, 2008-2012.

Figure 6.—Average percent cover of reed canarygrass on plots where it occurred, 2008-2012.

3Average percentage coverage is based on subplot data and is calculated for 

the portion of the plot which is forested. Each FIA plot consists of four circular 

1

⁄24-acre subplots located at the corners and center of an equilateral triangle 

that is 208 feet on a side.
4

Reed canarygrass, a plant often used for site 

restoration, was more common on plots near 

roads. There was a significant difference (p<0.01) 

in the distance to the nearest road for plots with 

and without reed canarygrass (Fig. 7). Roads are 

a conduit for seed dispersal and alter light and 

nutrient availability, as well as drainage. Vehicles 

traveling on roads carry propagules of many 

exotics, which become dispersed along them. 

Roads have been found to be important vectors 

for IPS (Kurtz and Hansen 2013, Lundgren et 

al. 2004, Predick and Turner 2008). Due to the 

effects of roads and fragmentation, it is important 

to keep forest land intact.

Characteristics of Plots with Reed Canarygrass

Figure 7. —Average distance to the nearest road for 

plots with or without reed canarygrass, 2008-2012.

Figure 8.—Trees per acre ≥1 inch d.b.h. with or without 

reed canarygrass.

Figure 9.—Trees per acre ≥5 inches d.b.h. with or without 

reed canarygrass.

Figure 10.—Number of invasive plant 

species other than reed canarygrass on 

plots with or without reed canarygrass.

*Note: the error bars in figure 7 through 10 show a 68% confidence interval for the 

observed mean.

Tree cover also differs for plots with and without reed canarygrass. The current data (2008-2012) suggest 

that there are fewer trees per acre on plots with reed canarygrass (Fig. 8 and 9; p<0.01). Since the study has 

been ongoing for only a short period of time (2007 implementation across all of the NRS region), it is difficult 

to assess whether the invasive plants are influencing tree regeneration and growth or if the invasive plants 

are establishing where there is low tree cover and less competition. Continued investigation into this matter is 

important because these plants can outcompete native species and without adequate understory regeneration 

to replace the aging overstory, the future of the forest remains in question. These preliminary investigations 

are important as they suggest there is a difference between plots with and without reed canarygrass present 

and future studies will help determine the effects these species are causing.

Analyzing plots with and without reed canarygrass shows there is no 

significant difference in the number of IPS on plots with or without reed 

canarygrass (Fig. 10). This differs from what was found with other invasive 

plants in this region (e.g., garlic mustard) (Kurtz and Hansen 2014). This may 

be because the preferred site characteristics of this species differ from other 

species and because this species is often used for restoration (e.g., along 

logging roads).

Monitoring IPS is important to determine status, distribution, population size, 

and influential plot characteristics, as well as to detect new populations. The 

trends discussed in this research note are valuable and need to be reported 

in the future to help elucidate important factors related to the presence of 

the monitored invasives as well as to find out the impacts these species are 

causing on biota and ecosystems. This research offers nonbiased data to land 

managers and other concerned individuals to help understand the implications 

of these species and to assist in making well-informed management decisions.
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Citation for this Publication

Kurtz, C.M.; Hansen M.H. 2014. An assessment of reed canarygrass in northern U.S. forests. Res. Note NRS-200. Newtown 

Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 5 p.

FIA Program Information

Bechtold, W.A.; Patterson, P.L., eds. 2005. The enhanced Forest Inventory and Analysis Program: national sampling design 

and estimation procedures. Gen. Tech. Rep. SRS-80. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern 

Research Station. 85 p.

Smith, W.B. 2002. Forest inventory and analysis: a national inventory and monitoring program. Environmental Pollution. 116: 

233-242.

U.S. Forest Service. 2012. Forest inventory and analysis national core field guide, Vol. 1: field data collection procedures 

for phase 2 plots, ver. 6.0. Available at www.fia.fs.fed.us/library/field-guides-methods-proc/ (verified 21 Apr 2014).

Other References

Czarapata, E.J. 2005. Invasive plants of the upper Midwest: an illustrated guide to their identification and control. Madison, 

WI: The University of Wisconsin Press. 215 p. 

Kurtz, C.M. 2010. Effects of site and climate characteristics on forest invasibility by non-native plants in the Midwest.

Minneapolis, Minnesota. 65 p. M.S. thesis.

Kurtz, C.M. 2013. An assessment of invasive plant species monitored by the Northern Research Station Forest Inventory 

and Analysis Program, 2005 through 2010. Gen. Tech. Rep. NRS-109. Newtown Square, PA: U.S. Department of Agriculture, 

Forest Service, Northern Research Station. 70 p.

Kurtz, C.M.; Hansen, M.H. 2013. An assessment of multiflora rose in northern U.S. forests. Res. Note NRS-182. Newtown 

Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 5 p.

Kurtz, C.M.; Hansen, M.H. 2014. An assessment of garlic mustard in northern U.S. forests. Res. Note NRS-199. Newtown 

Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 5 p.

Lavergne S.; Molofsky J. 2004. Reed Canary Grass (Phalaris arundinacea) as a Biological Model in the study of plant 

invasions. Critical Reviews in Plant Sciences. 23(5): 415-429.

Lundgren, M.R.; Small, C.J.; Dreyer, G.D. 2004. Influence of land use and site characteristics on invasive plant abundance in 

the Quinebaug Highlands of southern New England. Northeastern Naturalist. 11(3): 313-332.

Predick, K.I.; Turner, M.G. 2008. Landscape configuration and flood frequency influence invasive shrubs in floodplain 

forests of the Wisconsin River (USA). Journal of Ecology. 96:91-102.

Natural Resource Conservation Service. (NRCS). 2014. The PLANTS database. Greensboro, NC: U.S. Department of Agriculture, 

Natural Resource Conservation Service, National Plant Data Team. Available at http://plants.usda.gov (Accessed: 21 Apr 2014).

Additional Invasive Plant Information

Alien Plant Invaders of Natural Areas (PCA, National Park Service): http://www.nps.gov/plants/alien/factmain.htm

Invasive and Exotic Plants: http://www.invasive.org/species/weeds.cfm

Invasive Plant Atlas of New England: http://www.eddmaps.org/ipane/

Invasive Plant Atlas of the United States: http://www.invasiveplantatlas.org/index.html

Midwest Invasive Plant Network: http://mipn.org/

Contact

Analyst: Cassandra Kurtz, 651-649-5149; cmkurtz@fs.fed.us

Page 1 and 5 header by: Chris Evans, Illinois Wildlife Action Plan, Bugwood.org

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