Minnesota plant lists

Example of a rain garden planted with native vegetation.

This page introduces sources for the selection of plants for stormwater BMPs, salt tolerance, and green roofs.

Sources for stormwater BMP plant material selection

The following agencies provide up to date information on plant material selection for vegetated stormwater BMPs .

• Minnesota Pollution Control Agency
• Rice Creek Watershed District: click on the Best Management Practices browser
• Minnesota Department of Transportation:
• Minnesota Board of Water and Soil Resources: Seed Mix: BWSR W4 for ditches and wet swales

There are two specific situations in which these above sources should not be used: high salt concentrations (in spray and soil) and green roofs. Recommendations on salt tolerant and green roof plant material selection are given below.

Salt tolerance

Locations where salt tolerance is a concern include roadsides receiving frequent winter snowmelt spray, vegetated swales or basins where snowmelt runoff infiltrates the soil, and water bodies receiving relatively large volumes of snowmelt. This discussion is limited to selection of vegetation for constructed stormwater BMPs and vegetated areas receiving runoff from high use transportation routes and parking lots, wet and dry infiltration basins associated with regional ponding, county and state roadway swales and filter strips, and winter road snow dumping areas.

Salt tolerance is not a concern for stormwater BMPs such as rain gardens and infiltration swales in low to moderate use local streets and catchments with little or no salt-laden snowmelt runoff.

Salt tolerance is common to many plants of coastal marshy areas. These species are reliable on the east and west coast in their indigenous ranges. Some of these species are very widespread. The populations found in the Midwest are not necessarily salt tolerant. For inland areas the availability of naturally occurring populations of salt tolerant species is limited.

Salt tolerance has been shown in some of the dry grassland species of the west. The range of these species may include Minnesota. The local populations may exhibit salt tolerance and are recommended.

Salt tolerance has also been shown in some of the aggressive and invasive species found in the Midwest. These species, although amenable to the high salt areas are not recommended because of the stress that may be introduced to native plant communities. Depending on the species, their seeds may travel fairly far by wind or water and are not recommended for rural or urban areas, even if native plant communities are not adjacent.

Stormwater BMPs with high salt concentrations will be susceptible to invasion by exotic and invasive species due to multiple stressors from the salt, along with sedimentation and high phosphorus concentrations and petroleum products. Common buckthorn, one of the aggressive Midwest exotic species of saturated soils, has high salt tolerance. Box elder, a native of lowlands, but often a colonizer in disturbed sites also has high tolerance. Reed-canary grass has moderate tolerance, and purple loosestrife has high tolerance.

The table below lists species and plant seed mixes which should be reliable in soils with high salt concentrations. The tolerance to salt spray may vary, and is shown in parentheses if known. The plant materials listed do not include highly aggressive and invasive species.

Salt tolerance ratings can vary across the country and between investigators, depending on the ways the data are collected and the ratings categories selected. Rating systems are not standardized between various investigators for different plant types (trees, shrubs, herbs) and uses (agriculture, horticulture). The sources sited here were used to represent as best as possible recent research, regional evaluations, and results from specialized salinity testing laboratories.

Note that information on salt tolerance for Minnesota plants warrant some interpretation. Much of the salt tolerance information published nationally is oriented toward agriculture rather than stormwater BMPs. The first table below attempts to interpret data from the literature for applicability to Minnesota. The second table below provides sources for seed mixes.

Cold climate plant materials of the upper midwest with known salt tolerance, listed from wet to ery soil moisture

Recommended salt tolerant mixes
Link to this table

DESCRIPTION: Combination native and turf mix. Reaches a height of approximately 18 inches. For use inurban areas where conditions may be saline, droughty & generally poor soils. Oats to be substituted for Winter Wheat in spring plantings at a ratio of 1 to 1. RATE: 60 lbs/acre (67.2 kg/ha)
Common Name	Scientific Name	# Pounds	Percentage
Grama Sideoats	Bouteloua Curtipendula	4.80	8.00%
Grama Blue	Bouteloua Graciis	3.60	6.00%
Prairie Clover Purple	Dalea Purpureum	1.20	2.00%
Wildrye Canada	Elymus Canadensis	2.40	4.00%
Wheat Grass Slender	Elymus Trachycaulus	3.60	6.00%
Rye Grass Annual	Lolium Talicum	4.80	8.00%
Wheat Winter	Talicum Aestivum	15.60	26.00%
Bluegrass Canada	PCA Compressa	7.20	12.00
Grass Alkali	Puccinella Distans	9.60	16.00%
Bluestem Little	Schizachyrium Scoparium	6.00	10.00%
Dropseed Sand	Sporobolus Cryptandrus	1.20	2.00%X
	Totals	60.00	100.00%
Pounds of cover crop to be bagged seperately (Tech Memo 04-09-ENV-02		78.00
Mixture 10B (western Tall Grass Prairie): Grasses are PLS Forbs & introduced are bulk, yellow tag when available. DESCRIPTION: Native mix. Reaches a height of 36 to 48 inches. For use in western Minnesota. Oats to be substituted for Winter Wheat in spring plantings at a ratio of 1 to 1. RATE: 30 lbs/acre (33 kg/ha)
Common Name	Scientific Name	# Pounds	Percentage
Bluestem Big	Andropogon Gerardi	1.80	6.00%
Grama Sideoats	Bouteloua Curtipendula	2.40	8.00%
Wildrye Canada	Elymus Canadensis	1.80	6.00%
Wheat Grass Slender	Elymus Trachycaulus	1.20	4.00%
Wheat Grass Western	Elytrigia SmithA	0.60	2.00%
Rye Grass Annual	Lolium Talicum	3.00	10.00%
Wheat Winter	Talicum Aestivum	10.20	34.00%
Forbes F-1 or F-2	N/A	1.50	5.00%
Switchgrass Wild Type	Panicum Virgatum	0.30	1.00%
Bluestem Little	Schizachyrium Scoparium	3.00	10.00%
Indian Grass	Sorghastrum Nutans	3.00	10.00%
Needle Grass Green	Stipa Viridula	1.20	4.00%
	Totals	30.00	100.00%
Pounds of cover crop to be bagged seperately (Tech Memo 04-09-ENV-02		51.00

Photo of a green roof

Some common Midwest species are known to be intolerant of high salt soil concentrations. Avoid planting these species or seed mixes when salt is expected to be a stressor.

• Grey dogwood (Cornus racemosa)
• Red-osier dogwood (Cornus stolonifera)
• Silver maple (Acer saccharinum)
• Sugar maple (Acer saccharum)
• Basswood (Tilia Americana)

Green roofs

Information: Information on plants for green roofs has been updated. This updated information is shown in the tables below.

The green roof BMP has the most specialized circumstances for plant materials and thus requires a very different list of materials compared to on-the-ground BMPs. More than any other BMP, it is unwise to proceed on selecting green roof plant materials without full knowledge of the entire green roof structural design system. This has to do with the very constrained growing conditions for this highly engineered BMP. Note that the following discussion relates to plant selection for green roofs and is not a design sheet for green roof BMPs.

The first consideration on plant material selection is the basic green roof design type. Extensive green roofs (EGRs) have been commonly using xeriscape types of plantings in a shallow, draughty growing medium. These types of plantings are more appropriate for urban rooftops (See the table below for planting recommendations). Intensive green roofs (IGR) include earth-bermed structures and tend to be heavier and reliant on richer, deeper substrates and may also have shrubs and trees. As such, the plant materials for extensive and intensive green roof systems are not usually the same. For example, the selections for an earth-berm IGR planting may be quite different from an EGR system. It should be noted that plant species and diversity can affect ecological function

Non-native succulent species appropriate for extensive green roofs in Minnesota. Note: Many species of sedums grow well on green roofs in Minnesota. The list below shows some of the most common species. Many other Sedum species can also perform well.
Link to this table

Scientific name	Common name	Plant height (inches)	Approximate bloom time	Flower color	Sun exposure	Winter interest
Allium schoenoprasum	Chives	10	Spring	White	Full sun to partial shade	Dormant
Sedum album	Stonecrop	6	Summer	White	Full sun	Red
Sedum hybridum 'Immergrünchen'	Stonecrop	6	Summer	Yellow	Full sun	Orange/bronze
Sedum kamtschaticum var. floriferum'Weihenstephaner Gold'	Russian Stonecrop	5	Summer	Yellow	Full sun	Red
Sedum kamtschaticum	Russian Stonecrop	6	Summer	Yellow	Full sun	Red
Sedum reflexum 'Blue Spruce'	Stonecrop	8	Summer	Yellow	Full sun	Blue-green
Sedum rupestre 'Angelina'	Golden Stonecrop	5	Summer	Yellow	Full sun	Coral/orange-red
Sedum sexangulare	Stonecrop	4	Summer	Yellow	Full sun to shade	Red
Sedum spurium 'Dragon's Blood'	Two Row Stonecrop	4	Summer	Red	Sun	Red

Native species that have been grown successfully on extensive green roofs in Minnesota
Link to this table

Scientific name	Common name	Plant height (feet)	Approximate bloom time	Flower color	Sun exposure	Found to require irrigation in some projects or studies	Found to survive with little or no irrigation in some studies or projects
Allium cernuum	Nodding Wild Onion	1 to 1.5	July-August	Pink	Full sun to part shade		X3,4
Allium stellatum	Prairie Wild Onion	1 to 2	July-August	Pink	Full sun to part shade
Andropogon gerardii	Big Bluestem	2 to 6	n/a	n/a	Full sun to part shade		X1,2,*
Anemone patens	Pasque flower	0.5	April-May	Purple	Full Sun to Part Shade
Antennaria neglecta	Field pussytoes	0.5	April-June	White	Full Sun to Part Shade
Antennaria plantaginafolia	Pussytoes	1	April-June	White	Full sun to part shade
Aquilegia canadensis	Columbine	2 to 3	May-July	Red/Yellow	Full sun to part shade
Asclepias verticillata	Milkweed	1 to 1.5	June-August	White	Full sun to part shade
Aster ericoides	Heath aster	1 to 3	July-October	White	Full sun to part shade
Aster laevis	Smooth aster	1 to 3	August-October	Blue-violet	Full sun to part shade	X4
Aster lateriflorus	Calico aster	2	August-October	White	Full sun to part shade
Aster macrophyllus	Large-Leaved aster	1 to 2	August-October	Lilac	Full sun to part shade
Aster novae-angliae	New England Aster	3 to 5	August-October	Red-violet	Full sun to part shade
Aster oolentangiensis	Shyblue aster	3	August-October	Blue	Full sun to part shade
Aster sericeus	Silky aster	1	September-October	Purple	Full sun to part shade
Bouteloua curtipendula	Side-Oats Grama	1 to 3	n/a	n/a	Full sun		X1,*
Bouteloua gracilis	Blue Grama Harebell	0.5 to 1	n/a	n/a	Full sun		X1,5,*
Campanula rotundifolia	Harebell	1 to 1.5	June-September	Blue	Full sun to part shade
Carex pensylvanica	Pennsylvania sedge	0.5	n/a	n/a	Full sun to full shade
Carex vulpinoidea	Brown Fox Sedge	1 to 3	n/a	n/a	Full sun to part shade
Chamaecrista fasciculata	Partridge Pea	2 to 3	July-September	Yellow	Full sun to part shade
Coreopsis palmata	Bird's Foot Coreopsis	2	June-August	Yellow	Full sun to part shade
Dalea purpurea	Purple Prairie Clover	1 to 2	June-July	Yellow	Full sun	X4	X1
Fragaria vesca	Wild strawberry	0.5	May-June	White	Full sun to part shade
Fragaria virginiana	Wild strawberry	0.5	White	Full sun to part shade	X4	X1,*
Geranium maculatum	Wild geranium	1	April-June	Pink	Full sun to full shade
Geum triflorum	Prairie smoke	0.5	April-June	Red	Full sun to part shade		X1,*
Heuchera richardsonii	Alumroot	1	May-June	Greenish white	Full sun to full shade
Koeleria pyramidata	June grass	2	n/a	n/a	Full sun to part shade	X4	X1,2,3
Liatris aspera	Rough Blazing Star	1.5 to 4	August-September	Rose, lavender	Full sun to part shade	X4
Liatris cylindracea	Cylindric Blazing Star	1	July-October	Purple	Full sun to part shade
Penstemon grandiflorus	Large-Flowered Beard Tongue	2	May-June	Purple	Full sun to part shade
Phlox divaricata	Woodland Phlox	0.5 to 1.5	April-June	Blue	Part shade to full shade
Polemonium reptans	jacob's Ladder	1	April-June	Blue	Full sun to full shade
Ruellia humilis	Wild Petunia	1	June-August	Purple	Full sun
Schizachyrium scoparium	Little Bluestem	3	n/a	n/a	Full sun to part shade	X4
Solidago nemoralis	Gray Goldenrod	0.5 to 2	August-October	Yellow	Full sun
Solidago ptarmicoides	Upland White Aster	1	July-August	White	Full sun
Sporobolus heterolepis	Prairie Dropseed	2 to 4	n/a	n/a	Full sun to part shade	X4	X1
Thalictrum dioicum	Early Meadow-Rue	1 to 2	May	Greenish yellow	Full sun to part shade
Tradescantia bracteata	Bracted Spiderwort	1	May-July	Purple	Full sun
Tradescantia occidentalis	Western Spiderwort	2	May-July	Blue	Full sun
Tradescantia ohiensis	Ohio Spiderwort	3	May-July	Blue	Full sun to part shade	X3,4
Viola pedatifida	Bearded Birdfoot Violet	0.5	April-June	Purple	Full sun to part shade

¹Based on trial green roofs at Chicago Botanical Garden, Richard Hawke, Personal Communication
²Based on Kevin Carroll, personal communication, 2013.
³Based on research at Michigan State University, Rowe in Sutton et al 2012b
⁴Based on research at Michigan State University, Monterusso et al 2005. In this study, plants were irrigated the first growing season, and irrigation was then abruptly stopped July 10 of the second growing season, during an unusually warm and dry summer; plants were not irrigated at all during the third growing season.
⁵Based on observations at Phillips Eco-Enterprise green roof, The Kestrel Design Group personal communication, 2013.
^*Goes dormant or turns brown with little or no irrigation in drought but rebounds when water is available again.

Secondly, the plant material selection, through biological processes and nutrient cycling, may effect whether the BMP exacerbates or mitigates the function of nutrient storage. Research to date comparing EGRs and control (nongreen) roofs shows that green roofs are a poor BMP for nutrient storage and removal from precipitation. In evidence from both southern and northern climates, total phosphorus concentrations are higher in runoff leaving a green roof compared to control roofs, although the mass loading is the same as the control (Moran et al., 2004). Nitrogen losses from a green roof do not differ significantly from control roofs. So for nutrient loading and design of removal systems, other BMP tools should be located ‘further down the runoff path’ from the rooftop BMP to trap runoff from green roofs. It is unclear how the IGRs function for nutrient storage.

Extensive green roofs are definitely a reliable BMP for reducing peak runoff rates. This has been demonstrated in several controlled studies in both southern and northern climates. Intensive green roofs provide the same function. It is not clear if the plant material plays a significant role in this or whether it is related to the design of the planting medium and underlying roof runoff system. To date it has always been assumed that the overall design should support plant materials that are tolerant of drought conditions and not prolonged saturated soil.

There is plenty of opportunity for experimentation on green roof plant material. Most controlled experiments have been limited in the kinds of plant material tested. The Genus Sedum has been widely used in extensive green roof plantings. It is unknown whether plantings dominated by other and widely different plant groups will yield the same results. As such, the function of a green roof as a stormwater BMP may vary: nutrient storage may not be an issue with some plant materials. Until further case studies and experiments are conducted on the nutrient storage function of this BMP, it is wise to assume that all plant material selections will yield added nutrient runoff, particularly if the plants are fertilized. Thus, the green roof system should be designed in series with other BMPs which are expected to function in this respect.

The variety of choices of EGR plant material for warm and cold climates is generally limited in the following ways:

• Water and nutrients from precipitation
• Substrate - often at least partially synthetic and droughty
• Limited organic matter build up – isolated from organic debris, leaf build-up, sedimentladen runof
• Shallow rooting zone – less than one foot

Plant selection is restricted to materials which will be successful in very shallow substrates, perhaps 6 inches, up to 12 inches deep. Long-lived, perennial drought tolerant species commonly display deep taproot growth or deep fibrous root systems. This is the main reason that the Genus Sedum is so commonly relied upon. In contrast, many of the prairie forbs and grasses valued for infiltration BMPs may not be appropriate for green roofs.

The plant material selection for any one specific green roof is also dependent on the substrate content and depth. Intensive and extensive systems were already defined, and will significantly effect the substrate choices. The plant material selections provided here have been limited to those for EGRs. Even within an extensive system, in which the substrate is in general droughty, the specific design of each system will significantly effect plant productivity. Experiments in which the same plant material was grown on several different substrates demonstrates the importance of this. As such, one of the main criteria for selecting EGR plants is the substrate design. And often, this is limited by the structural integrity of the building, particularly for retrofit designs.

For EGRs, irrespective of the specific design, one general consideration applies to establishing plant material. The material will usually be introduced as young plants, and to reduce transplant shock and provide an enriched environment for further growth, an organic substrate such as compost should be used as the immediate transplant medium.

References for salt tolerance

• Colorado State University Cooperative Extension Tri River Area. 2003. Salt Tolerance of Various Temperate Zone Ornamental Plants. Curtis E. Swift.
• Johnson, Gary R. and Ed Sucoff. 2000. Minimizing De-Icing Salt Injury to Trees. University of Minnesota Extension Service.
• Minnesota Department of Transportation. 2003 Seeding Manual. Office of Environmental Services, Erosion Control Unit.
• University of California, Riverside. George E Brown Jr Salinity Laboratory.
• University of Wiscsonsin-Extension. 1999. Salt Injury to Landscape Plants. Delahaut, K.A. and E.R. Hasseljus. Cooperative Extension Publishing.

References for green roof plant material selection

• Bengtsson, L. 2004. Hydrological Response of Sedum-Moss Roof. American Geophysical Union. Fall Meeting 2004. abstract #H41A-0285.
• DeNardo, J.C., A.R. Jarrett, H.B. Manbeck, D.J. Beattie, and R.D. Berghage. 2003. Stormwater Detention and Retention Abilities of Green Roofs. World Water and Environmental Resources Congress. 2003. Paul Bizier, Paul DeBarry - Editors, June 23–26, 2003, Philadelphia, Pennsylvania, USA.
• Federal Energy Management Program. September 2004. Green Roofs. DOE/EE-0298.
• Moran, Amy, Bill Hunt, Greg Jennings. 2004. Greenroof Research of Stormwater Runoff Quantity and Quality in North Carolina. NCSU Water Quality Group Newsletter August 2004.
• Shooting Star Native Seeds. 2005. Mn/DOT 2005 Seed Mixes.
• Uhl, M, Schiedt, L, Mann, G, Henneberg, M. 2003. Long-term study of rainfall runoff from green roofs. Wasser und Boden. Vol. 55, no. 3, pp. 28-36. Mar. 2003.