image of plant book
The tables and content on this page have been adapted from “Plants for Stormwater Design: Species Selection for the Upper Midwest” (Daniel Shaw and Rusty Schmidt, Minnesota Pollution Control Agency, 2003).
Green Infrastructure: Swales can be an important tool for retention and detention of stormwater runoff. Depending on design and construction, swales may provide additional benefits, including cleaner air, carbon sequestration, improved biological habitat, and aesthetic value. See the section Green Stormwater Infrastructure (GSI) and sustainable stormwater management.

The tables and content on this page have been adapted from “Plants for Stormwater Design: Species Selection for the Upper Midwest” (Daniel Shaw and Rusty Schmidt, Minnesota Pollution Control Agency, 2003). To obtain a free copy of this guidebook, telephone (651) 297-8679 or write to Operations and Environmental Review Section, Regional Environmental Management Division, Minnesota Pollution Control Agency, 520 Lafayette Rd. N., Saint Paul, MN 55103-1402.

  • Zone 1: Submergent zone; 1.5 to 6 feet of water
  • Zone 2: Emergent zone; 0 to 18 inches of water
  • Zone 3: Wet meadow zone; permanent moistue
  • Zone 4: Floodplain zone; flooded during snowmelt and large storms
  • Zone 5:Upland zone; seldom or never inundated (the upland zone includes prairie and forest plant communities)

Zone 1 (Submergent zone) – The submergent zone is found in areas of 3-6 feet of water in wet ponds. Therefore, it is an unlikely zone to include in a Swale design, though exceptions may occur. Submergent vegetation makes up this zone because emergent vegetation generally does not grow deeper than 3 feet. Submergent species may float free in the water column or may root in the pool bottom and have stems and leaves that generally stay under water. Submergent species are important for wildlife habitat and pollutant removal, especially nitrates and phosphorus. Submergent species are not readily available from native plant nurseries and can be difficult to plant. Many submergent species establish on their own (Ogle and Hoag 2000).

Zone 2 (Emergent zone) – The emergent zone of a wet pond is generally 0 to 18 inches deep. It is often designed as benches within ponds to optimize the area for emergent plants. This zone is most common to Swale designs from the center of the Swale to, typically, the water quality stage elevation. Emergent plants are important for wildlife and evapotranspiration. They also provide habitat for phytoplankton, which play an important role in nutrient removal (Ogle and Hoag 2000). A wide variety of wetland species are adapted to the emergent zone. However, large fluctuations in water level and pollutants within wet ponds may limit the number of species.

Zone 3 (Wet meadow zone) – The wet meadow zone is a constantly moist area that can become inundated. The transition area between open water and the shoreline is prone to erosion. Therefore, it is an important area for plant establishment. This zone extends from Zone 2 to the Zone 4 and is common in swale designs. In addition to wet-meadow grasses, sedges, flowers and shrubs, such as dogwoods, willows, buttonbush and chokeberry, are well suited to this zone.

Zone 4 (Floodplain zone) – The floodplain zone is normally dry but may flood during snowmelt and after large storms. This zone can occur in Swales designed with 2-stages of inundation; one for water quality storage and the second for channel protection storage. It should be noted that small depression storage can be built into this zone as wetland storage areas for additional treatment and habitat enhancement. These depressions would be considered either Zone 1-3, depending on depth and duration of inundation. Floodplain zones are generally flat terraces and are common along rivers and streams. If a wet pond has a steep side slope, it may go directly from zone 3 (wet meadow zone) to zone 5 (upland zone) without having a floodplain zone. Floodplain species must be adapted to extremes in hydrology; they may be inundated for long periods in the spring and be dry during the summer. The ability of floodplain species to handle extremes in hydrology make them well suited to the edges of wet ponds and detention ponds.

Zone 5 (Upland zone) – The upland zone is seldom or never inundated. A wide variety of species are well adapted to the upland zone and their selection will depend on the site conditions.

Zone 2 (Emergent zone)

plant photo
Marsh marigold, Zone 2. From Shaw and Schmidt (2003).
Zone 2 - Emergent zone (0 - 18 inches of water)
Scientific name Common name
Forbs and ferns
Acorus calamus Sweet flag
Alisma trivale Water plantain
Caltha palustris Marsh marigold
Polygonum amphibium Water smartweed
Pontederia cordata Pickerelweed
Sagittaria latifolia Broadleaved arrowhead
Sparganium eurycarpum Giant burreed
Grasses, sedges, and rushes
Carex aquatilis Water sedge
Carex lacustris Lake sedge
Carex stricta Tussock sedge
Juncus balticus Baltic rush
Juncus effusus Soft rush
Scirpus acutus Hardstem bulrush
Scirpus Fluviatilis River bulrush
Scirpus pungens Three-square bulrush
Scirpus validus Soft-stem bulrush
Zone 3 - Wet meadow zone; permanent moisture
Scientific name Common name
Trees and shrubs
Amorpha fruticosa Indigo bush
Salex nigra Black willow
Sambucus pubens Red-berried elder
Forbs and ferns
Thalictrum dasycarpum Tall meadowrue
Verbena hastata Blue vervain
Vernonia fasciculata Ironweed
Veronicastrum virginicum Culver's root
Grasses, sedges, and rushes
Andropogon gerardii Big bluestem
Bromus ciliatus Fringed brome
Calamagrostis canadensis Canada blue-joint grass
Carex bebbii Bebb's sedge
Carex comosa Bottlebrush sedge
Carex crinita Caterpillar sedge
Carex hystericina Porcupine sedge
Carex languinosa Wooly sedge
Carex lasiocarpa Wooly needle sedge
Carex retrorsa Retrorse sedge
Carex stipata Awl-fruited sedge
Carex vulpinoidea Fox sedge
Eleocharis obtusa Blunt spikerush
Equisetum fluviatile Horsetail
Glyceria grandis Giant manna grass
Glyceria striata Fowl manna grass
Juncus balticus Baltic rush
Juncus effusus Soft rush
Juncus torreyi Torrey rush
Leersia oryzoides Rice-cut grass
Panicum virgatum Switchgrass
Scirpus atrovirens Green bulrush
Scirpus cyperinus Woolgrass
Scirpus fluviatilis River bulrush
Scirpus pungens Three-square bulrush
Scirpus validus Soft-stem bulrush
Spartina pectinata Prairie cord grass
Zone 4 - Floodplain zone; flooded during snowmelt and large storms
Scientific name Common name
Trees and shrubs
Acer saccharinum Silver maple
Alnus incana Speckled alder
Amorpha fruticosa Indigo bush
Aronia melanocarpa Black chokecherry
Betula nigra River birch
Celtis occidentalis Hackberry
Cephalanthus occidentalis Buttonbush
Cornus amomum Silky dogwood
Cornus sericea Red-osier dogwood
Fraxinus nigra Black ash
Fraxinus pennsylvanica Green ash
Physocarpus opulifolius Ninebark
Populus deltoides Eastern cottonwood
Quercus bicolor Swamp white oak
Salix discolor Pussy willow
Salix exigua Sandbar willow
Salix nigra Black willow
Sambucus pubens Red-berried elder
Spiraea alba Meadowsweet
Viburnum lentago Nannyberry
Viburnum trilobum High bush cranberry
Forbs and ferns
Anemone canadensis Canada anemone
Aster lucidulus Swamp aster
Aster puniceus Red-stemmed aster
Boltonia asteroides Boltonia
Impatiens capensis Jewelweed
Lobelia cardinalis Cardinal flower
Lobelia siphilitica Blue lobelia
Lysimachia thrysiflora Tufted loosestrife
Physostegia virginiana Obedient plant
Potentilla palustris Marsh cinquefoil
Scutterlaria lateriflora Mad-dog skullcap
Silphium perfoliatum Cup plant
Symplocarpus foetidus Skunk cabbage
Vernonia fasciculata Ironweed
Grasses, sedges, and rushes
Carex comosa Bottlebrush sedge
Elymus virginicus Virginia wild rye
Leersia oryzoides Rice-cut grass
Panicum virgatum Switchgrass
Scirpus atrovirens Green bulrush
Spartina pectinata Prairie cord grass
Zone 5 - Upland zone; seldom or never inundated
Scientific name Common name
Trees and shrubs
Cornus racemosa Gray dogwood
Populus tremuloides Quaking aspen
Quercus bicolor Swamp white oak
Viburnum lentago Nannyberry
Viburnum trilobum High bush cranberry
Forbs and ferns
Agastache foeniculum Giant hyssop
Allium stellatum Prairie wild onion
Arisaema triphyllum Jack-in-the-pulpit
Artemisia ludoviciana Prairie sage
Asclepias tuberosa Butterfly milkweed
Aster laevis Smooth aster
Aster lanceolatus (simplex) Pacicled aster
Aster macrophyllus Bigleaf aster
Aster pilosus Frost aster
Athyrium filix-femina Lady fern
Boltonia asteroides Boltonia
Epilobium angustifolium Fireweed
Galium boreale Northern bedstraw
Helianthus grosseserratus Sawtooth sunflower
Heuchera richardsonii Prairie alumroot
Monarda fistulosa Wild bergamot
Onoclea sensibilis Sensitive fern
Potentilla palustris Marsh cinquefoil
Pteridium aquilinum Bracken fern
Pycnanthemum virginianum Mountain mint
Ratibida pinnata Yellow coneflower
Rudbeckia subtomentosa Brown-eyed susan
Smilacina racemosa False Solomon's seal
Solidago flexicaulis Zig-zag goldenrod
Solidago riddellii Riddell's goldenrod
Solidago rigida Stiff goldenrod
Tradescantia ohiensis Ohio spiderwort
Veronicastrum virginicum Culver's root
Grasses, sedges, and rushes
Andropogon gerardii Big bluestem
Panicum virgatum Switchgrass
Schizachyrium scoparium Little bluestem
Sorghastrum nutans Indian grass

The emergent zone of a wet pond is generally 0 to 18 inches deep. It is often designed as benches within ponds to optimize the area for emergent plants. This zone is most common to Swale designs from the center of the Swale to, typically, the water quality stage elevation. Emergent plants are important for wildlife and evapotranspiration. They also provide habitat for phytoplankton, which play an important role in nutrient removal (Ogle and Hoag 2000). A wide variety of wetland species are adapted to the emergent zone. However, large fluctuations in water level and pollutants within wet ponds may limit the number of species.

Zone 3 (Wet meadow zone)

The wet meadow zone is a constantly moist area that can become inundated. The transition area between open water and the shoreline is prone to erosion. Therefore, it is an important area for plant establishment. This zone extends from Zone 2 to the Zone 4 and is common in swale designs. In addition to wet-meadow grasses, sedges, flowers and shrubs, such as dogwoods, willows, buttonbush and chokeberry, are well suited to this zone.

Zone 4 (Floodplain zone)

The floodplain zone is normally dry but may flood during snowmelt and after large storms. This zone can occur in Swales designed with 2-stages of inundation; one for water quality storage and the second for channel protection storage. It should be noted that small depression storage can be built into this zone as wetland storage areas for additional treatment and habitat enhancement. These depressions would be considered either Zone 1-3, depending on depth and duration of inundation. Floodplain zones are generally flat terraces and are common along rivers and streams. If a wet pond has a steep side slope, it may go directly from zone 3 (wet meadow zone) to zone 5 (upland zone) without having a floodplain zone. Floodplain species must be adapted to extremes in hydrology; they may be inundated for long periods in the spring and be dry during the summer. The ability of floodplain species to handle extremes in hydrology make them well suited to the edges of wet ponds and detention ponds.

Zone 5 (Upland zone)

The upland zone is seldom or never inundated. A wide variety of species are well adapted to the upland zone and their selection will depend on the site conditions.

Plants for wet and dry swales

dry and wet swale photo
Dry swale and wet swale (no check dams). Dry swales must drain within 48 hours to meet permit requirements and therefore typically utilize Zones 4 and 5 plants. Wet swales are always wet and utilize Zones 2, 3, and occasionally Zone 4 plants.

Dry swales, sometimes called grass swales, are similar to bioretention cells but are configured as shallow, linear channels. They typically have vegetative cover. Dry swales may be constructed as filtration or infiltration practices, depending on soils. If soils are highly permeable (A or B soils), runoff infiltrates into underlying soils. In less permeable soils, runoff is treated by engineered soil media and flows into an underdrain, which conveys treated runoff back to the conveyance system further downstream. Check dams incorporated into the swale design allow water to pool up and infiltrate into the underlying soil or engineered media, thus increasing the volume of water treated.

Wet swales occur when the water table is located very close to the surface or water does not readily drain out of the swale. A wet swale acts as a very long and linear shallow biofiltration or linear wetland treatment system. Wet swales do not provide volume reduction and have limited treatment capability. Incorporation of check dams into the design allows treatment of a portion or all of the water quality volume within a series of cells created by the check dams. Wet swales planted with emergent wetland plant species provide improved pollutant removal. Wet swales may be used as pretreatment practices. Wet swales are commonly used for drainage areas less than 5 acres in size.

Select wet swale-appropriate plants
Scientific name Common name
Trees and shrubs
Alnus incana Speckled alder
Amorpha fruticosa Indigo bush
Aronia melanocarpa Black chokecherry
Betula nigra River birch
Cephalanthus occidentalis Buttonbush
Cornus amomum Silky dogwood
Cornus racemosa Gray dogwood
Cornus sericea Red-osier dogwood
Ilex verticillata Winterberry
Larix laricina Tamarck
Physocarpus opulifolius Ninebark
Salix discolor Pussy willow
Salix exigua Sandbar willow
Sambucus pubens Red-berried elder
Spiraea alba Meadowsweet
Viburnum lentago Nannyberry
Viburnum trilobum High bush cranberry
Forbs and ferns
Agastache foeniculum Giant hyssop
Alisma trivale Water plantain
Anemone canadensis Canada anemone
Angelica atropurpurea Angelica
Artemisia ludoviciana Prairie sage
Asclepias incarnata Marsh milkweed
Aster lanceolatus (simplex) Panicle aster
Aster lucidulus Swamp aster
Aster novae-angliae New England aster
Aster puniceus Red-stemmed aster
Boltonia asteroides Boltonia
Caltha palustris Marsh marigold
Chelone glabra Turtlehead
Equisetum fluviatile Horsetail
Eryngium yuccifolium Rattlesnake master
Eupatorium maculatum Joe-pye-weed
Eupatorium perfoliatum Bonset
Euthanmia graminifolia Grass-leaved goldenrod
Gentiana andrewsii Bottle gentian
Helenium autumnale Sneezeweed
Helianthus grosseserratus Sawtooth sunflower
Impatiens capensis Jewelweed
Iris versicolor Blueflag
Liatris ligulistylis Meadow blazingstar
Liatris pychnostachya Prairie blazingstar
Lilium superbum Turks-cap lily
Lobelia cardinalis Cardinal flower
Lobelia siphilitica Blue lobelia
Lysimachia thrysiflora Tufted loosestrife
Monarda fistulosa Wild bergamot
Onoclea sensibilis Sensitive fern
Osmunda regalis Royal fern
Physostegia virginiana Obedient plant
Polygonum amphibium Water smartweed
Pontederia cordata Pickerelweed
Potentilla palustris Marsh cinquefoil
Pycnanthemum virginianum Mountain mint
Rudbeckia subtomentosa Brown-eyed Susan
Sagittaria latifolia Broadleaved arrowhead
Scutterlaria lateriflora Mad-dog skullcap
Silphium perfoliatum Cup plant
Solidago rigida Stiff goldenrod
Sparganium eurycarpum Giant burreed
Symplocarpus foetidus Skunk cabbage
Thalictrum dasycarpum Tall meadowrue
Tradescantia ohiensis Ohio spiderwort
Verbena hastata Blue vervain
Vernonia fasciculata Ironweed
Veronicastrum virginicum Culver's root
Zizia aurea Golden alexanders
Grasses, sedges, and rushes
Andropogon gerardii Big bluestem
Bromus ciliatus Fringed brome
Calamagrostis canadensis Canada blue-joint grass
Carex aquatilis Water sedge
Bebb's sedge
Carex comosa Bottlebrush sedge
Carex crinita Caterpillar sedge
Carex hystericina Porcupine sedge
Carex lacustris Lake sedge
Carex languinosa Wooly sedge
Carex lasiocarpa Wooly needle sedge
Carex retrorsa Retrorse sedge
Carex stipata Awl-fruited sedge
Carex stricta Tussock sedge
Carex vulpinoidea Fox sedge
Eleocharis obtusa Blunt spikerush
Elymus virginicus Virginia wild rye
Glyceria grandis Giant manna grass
Glyceria striata Fowl manna grass
Juncus balticus Baltic rush
Juncus effusus Soft rush
Juncus torreyi Torrey rush
Leersia oryzoides Rice-cut grass
Panicum virgatum Switchgrass
Scirpus acutus Hardstem bulrush
Scirpus atrovirens Green bulrush
Scirpus cyperinus Woolgrass
Scirpus fluviatilis River bulrush
Scirpus pungens Three-square bulrush
Scirpus validus Soft-stem bulrush
Spartina pectinata Prairie cord grass
Typha latifolia Broadleaved cattail
Select dry swale-appropriate plants
Scientific name Common name
Forbs and ferns
Anemone canadensis Canada anemone
Artemisia ludoviciana Prairie sage
Asclepias incarnata Marsh milkweed
Aster puniceus Red-stemmed aster
Euthanmia graminifolia Flat-top goldenrod
Lobelia siphilitica Blue lobelia
Pycnanthemum virginianum Mountain mint
Verbena hastata Blue vervain
Grasses, sedges, and rushes
Andropogon gerardii Big bluestem
Bromus ciliatus Fringed brome
Calamagrostis canadensis Canada blue-joint grass
Carex bebbii Bebb's sedge
Carex vulpinoidea Fox sedge
Elymus virginicus Virginia wild rye
Glyceria striata Fowl manna grass
Juncus effusus Soft rush
Panicum virgatum Switchgrass
Scirpus atrovirens Green bulrush
Spartina pectinata Prairie cord grass
Useful sod-forming grasses
Agrostis palustris Creeping bentgrass
Elymus sp. Wheat-grass
Poa palustris Fowl bluegrass

Pollinator specific plants

The MNDOT Seeding Manual also provides standard seed mixes designed for the conditions and locations shown in the tables below, as well as application rates and specifications.

Pollinator specific plants. Source: BWSR Pollinator Toolbox
Link to this table

Spring Summer Fall

Alumroot
American Basswood*
American Wild Plum*
Black Chokeberry
Broad-leaf Arrowhead
Blanketflower
Bloodroot^
Buttercups
Canada Anemone
Cherries*
Columbine^
Common Strawberry
Dogwoods
Dutchman’s Breeches*^
Elderberry
Field Blue-eyed
Grass Golden Alexander*
Hoary Puccoon Juneberries*
Large Flowered Bellwort^
Long-headed Thimbleweed
Lowbush Blueberry
Red Maple^
Large-Flowered Penstemon*
Nannyberry
Prairie Milk Vetch
Prairie Phlox
Prairie Smoke
Rue Anemone*
Solomon’s Seal
Spiderwort
Trillium Violets^
Virginia bluebells^
Virginia Waterleaf*^
White Baneberry^
Wild Lupine*
Wild Petunia
Willows (Salix sp.)

Angelica Bedstaws (Galium sp.)
Blazing Stars* (Liatris sp.)
Blue Lobelia*
Blue Vervain
Bottle Gentian
Bush Clovers
Buttonbush
Canada Anemone
Canada Milkvetch
Canada Tick Trefoil
Coreopsis*
Cow Parsnip
Culver’s Root*
Cup Plant*
Dogbane*
Dogwoods
Evening Primrose
False Indigo
False Sunflower*
Giant Hyssop*
Grass-leaved Goldenrod*
Harebell*
Hedge Nettle
Hoary Vervain*
Ironweed
Jewelweed
Joe-Pye Weed*
Large-leaved Aster^
Leadplant
Milkweeds*(Asclepias sp.)
Narrow Leaf Coneflower*
Native Loosestrifes
Native Thistles*
New Jersey Tea
Ninebark*
Obedient Plant*
Partridge Pea
Prairie Cinquefoil
Purple Prairie Clover*
Prairie Coneflower
Prairie Turnip
Prairie Wild Onion
Raspberries/Blackberries*
Smooth Sumac
Spotted Bee Balm
Snowberry/Wolfberry
Turtlehead
Virginia Mountain Mint*
Waterlilies
White Meadowsweet
Wild Bergamot*
Wild Indigo
Wild Iris
Wild Quinine*
Wild Mint
Smooth Wild Rose*
Yarrow

American Vetch
Annual Sunflower*
Black Eyed Susan Boneset*
Bugleweeds (Lycopus sp.)
Chickweeds Frost Aster*
Gentians*
Grass-leaved Goldenrod*
Maximilian’s Sunflower*
New England Aster*
Nodding Bur-Marigold*
Showy Goldenrod*
Sneezeweed*
Stiff Goldenrod*
Virginia Mountain Mint*
White Snakeroot^
Zig Zag Goldenrod*^

*High value for Pollinator Species
^Shade-tolerant species


Additional links and information

Note that while the resources below provide extensive information on plants that can be used in swales, some of the references are for other areas of the country. If using these resources, ensure the information is applicable to Minnesota.


Related pages

Dry swales

Wet swales

High-gradient stormwater step-pool swale

Stormwater step pools are currently not included as a BMP in the MIDS calculator. The swale main channel BMP can be used, but the maximum allowable slope is 4 percent. To dtermine volume retention for slopes greater than 4 percent, you will need to develop a relationship between the slope and volume retained. To do this, determine volume retention at 0.5 percent slope increments for your site at slopes ranging from 0.5 to 4 percent. Determine the appropriate regression for volume retention and slope and calculate the volume retained at the slope for your site. The relationship is not linear. Links to MIDS calculator information are provided below.

This page was last edited on 8 December 2022, at 17:15.