Plant lists for green roofs Revision as of 13:25, 19 June 2013 by Mtrojan (talk | contribs) (→‎Growing sedums and other succulent plants on green roofs)(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff) Plant lists for green roofs

Given adequate growing medium depth and irrigation, just about any plants, even trees, can be grown on green roofs. The plant list discussions below pertain to extensive green roofs.

While most of the first extensive green roofs in the US were planted with non-native succulent species, mostly Sedum species, the plant palette for green roofs in the US, and in Minnesota, is rapidly expanding to include many herbaceous plants and grasses.

Species included on the plant lists below may not be appropriate for all projects. Suitability can vary with climate, microclimate, project goals, and maintenance budget. Many of these green roof species have not yet been tested in all of Minnesota. While a considerable number of green roofs has been installed in the Twin Cities area, few green roofs have been installed to date in more northern parts of Minnesota, which have a harsher climate that will be more challenging for green roof vegetation.

See Design criteria for green roofs for guidance on factors that affect green roof plant selection.

Growing sedums and other succulent plants on green roofs

Photo of sedums on the Target Center Arena green roof in Minneapolis, MN. Image Courtesy of The Kestrel Design Group, Inc.

Sedums and other succulent plants are often used on green roofs because they are very tolerant of the dry conditions found on most roofs. Durhman et al (2006) found some Sedum species could survive and maintain active photosynthetic metabolism even after 4 months without water! A few of the hardiest ones for Minnesota are listed in Table 1, but these are only a very small portion of the huge palette of Sedums available on the market. Longer lists of succulents available for green roofs, are available, for example, in:

• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Bulletin E-3047. Downloaded May 1, 2013 from
• Snodgrass, E.C. and L.L. Snodgrass. 2006. Green Roof Plants: A Resource and Planting Guide. Timber Press.
• Catalog from Emory Knoll, a green roof plants nursery owned by the authors of the 2006 book about green roof plants by Snodgrass and Snodgrass, catalog can be downloaded from www.greenroofplants.com

Many research studies have studied growth of succulent plants on Midwestern green roofs. Dvorak and Volder (2010) summarized North American green roof vegetation studies published through March 2010. Other studies of succulents on Midwestern extensive green roofs that are not included in the Dvorak and Volder (2010) review include:

• Butler, C., & Orians, C. M. (2011). Sedum cools soil and can improve neighboring plant performance during water deficit on a green roof. Ecological Engineering,37(11). 1796–1803.
• Rowe, D. Bradley, Kristin L. Getter, and Angela K. Durhman. Effect of green roof media depth on Crassulacean plant succession over seven years. Landscape and Urban Planning (Elsevier) 104. (2012): 310-319.
• Whittinghill, L.J.; D.B. Rowe, 2011. Salt tolerance of common green roof and green wall plants. Urban Ecosystems. 14(4):783-794.

Non-native succulent species appropriate for extensive green roofs in Minnesota

Growing native species on green roofs

Similarities between bedrock bluff prairies and green roof habitats, image courtesy of The Kestrel Design Group, Inc.)

Many species found in Minnesota’s bedrock bluff prairies have also been found to grow well on Minnesota’s green roofs. Bedrock bluff prairies are prairies with very thin soil layers over bedrock, often found along river bluffs, so plants growing in bedrock bluff prairies are adapted to growing conditions very similar to those found on many green roofs: thin growing medium and high exposure to wind, sun, and drought. Use of native prairie species on green roofs is controversial, because most prairie species survive droughts by sending roots very deep into the soil to access water from deep down. The shallow growing medium of green roofs does not allow for such deep root growth. However, anecdotal observations in Minnesota, Michigan, Chicago IL and Lincoln NE, suggest that deep rooted native prairie species grow their roots horizontally on green roofs (Kestrel Design Group 2013, Sutton 2011, Grese 2008).

Some studies have found that many native species do not survive on green roofs without irrigation (e.g. Monterusso et al 2005). However, in some projects, even some native species thrive on green roofs without irrigation, or with very minimal irrigation. Since irrigation is needed during the plant establishment period anyway, many green roofs include an automatic irrigation system and can be easily irrigated if needed in times of drought. See task 5 for advantages and disadvantages of irrigating a green roof.

Native species have been planted on at least five extensive green roofs in the Twin Cities area, planted between 2005 and 2009 (See Case Studies for Examples). INSERT Figure 4.3: Native Plants on Target Center Arena Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc.; INSERT Figure 4.4: Native Plants on Minneapolis City Hall Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc.; INSERT Figure 4.5: Native Plants on Phillips Eco-Enterprise Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc. Table 2 lists some of the native species that have performed well on green roofs in Minnesota (Kestrel Design Group observations). Because all of these except for one are irrigated regularly, the ability of most of these species to survive without irrigation on extensive green roofs in Minnesota is not known. Species that have been found to survive with little or no irrigation in Minnesota or elsewhere in the Midwest are noted in table 2.

Many of the species listed in table 2, as well as many additional native species not listed in table 2, are also thriving on other Midwestern extensive green roofs, including, for example, Chicago City Hall (Dvorak and Carroll 2008, Carroll 2013), Chicago Botanic Gardens trial green roofs (Hawke 2013), and several other green roofs in Chicago, Toronto, and Lincoln NE. The Chicago City Hall green roof, installed in 2001 had 200 species as of 2012, most of which are natives. Its plants are grown in varying depths of soil (some extensive and some intensive), and regularly irrigated (Dvorak and Carroll, 2008). The Chicago Botanic Garden has 2 trial green roofs, installed in 2009, one of which is planted with natives. It includes planting depths of 4”, 6” and 8” of growing medium. Aiming to minimize green roof maintenance, they have watered the green roofs only during extreme drought (beyond establishment): once in 2011, and once in 2012 (Sutton et al 2012).

Dvorak and Volder (2010) summarized North American green roof vegetation studies published through March 2010, including those with native species.

Other publications of Midwestern green roofs planted with native species (not listed in Dvorak and Volder’s 2010 literature review) include:

• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Extension Bulletin E-3047. Downloaded May 1, 2013 from http://www.hrt.msu.edu/greenroof/PDF/08%20GetterRoweExtensionBulletin.pdf
• Sutton, R.K.; J.A. Harrington; L. Skabelund; P. MacDonagh; R. R. Coffman; and G. Koch. 2012. Prairie-Based Green Roofs: Literature, Templates, and Analogs. Journal of Green Building 7(1):143-172.
• Sutton, R.; B. Rowe;G. Acomb; J. Lambrinos; P. MacDonagh; R. Hawke. 2012. New Plant Performance for 21st Century Green Roof Ecosystems. Cities Alive Conference, Chicago IL.
• Torrance, S.; B. Bass, S. MacIvor and T. McGlade in conjunction with Toronto City Planning Division. No publication year given. City of Toronto Guidelines for Biodiverse Green Roofs. Downloaded May 1, 2013 from http://www.toronto.ca/greenroofs/pdf/biodiversegreenroofs_2013.pdf

Not all the species listed in the table below are native in all parts of Minnesota. To find out in which parts of Minnesota these species are native, see Plant species range maps from the Minnesota Department of Natural Resources. For additional information on the species listed in the table below, including wildlife and other benefits, see [1].

Native species that have been grown successfully on extensive green roofs in Minnesota

Growing non-native perennials and grasses on green roofs

While some drought tolerant non-native perennials would be expected to thrive on extensive green roofs, to our knowledge very little if any green roofs in Minnesota have attempted to grow perennials on extensive green roofs.

Growing edible plants on green roofs

Many vegetables and herbs also thrive on green roofs, many in growing medium as little as four inches deep, such as, for example, herbs, tomatoes, peppers, and lettuce. Because they are annuals, vegetables require considerably more maintenance than other extensive green roof plants. If they are fertilized, they will likely increase nutrient content of runoff from the roof, so they may not be ideal for stormwater projects where leaching of nutrients is a concern. If all runoff from the green roof is harvested and re-used on the roof, fertilization will not affect down stream water bodies.

Aside from growing food in a built in place green roof, food can also be grown in containers or hydroponically on a green roof, or on a green or living wall.

The St Paul, MN, fire station is a premier local example of growing food on a green roof. Many other examples of growing food on residential and commercial green roofs can also be found in the US and Canada, including

• Brooklyn Grange, a one acre (43,000 square foot) farm in Queens rooftop farming and intensive green roofing business located on two roofs in New York City, which grows over 40,000 lbs of organically-cultivated produce per year (http://www.brooklyngrangefarm.com/aboutthegrange/
• Eagle Street Rooftop Farm 6,000 square foot green roof organic vegetable farm located atop a warehouse rooftop owned by Broadway Stages in Greenpoint, Brooklyn (http://rooftopfarms.org/)

Several on-line references provide more detail about rooftop agriculture, including, for example, Guide to Setting Up Your Own Edible Rooftop Garden, Published by Alternatives and the Rooftop Garden Project, 2008, downloaded 04/15/2013 from http://archives.rooftopgardens.ca/files/howto_EN_FINAL_lowres.pdf

Other recent publications on rooftop agriculture include

• Mandel, L., 2013, EAT UP; The Inside Scoop on Rooftop Agriculture. New Society Publishers: Gabriola Island, BC, Canada.
• Whittinghill, L.J. and D.B. Rowe. 2012. The role of green roof technology in urban agriculture. Renewable Agriculture and Food Systems 27(4):314-322.
• Whittinghill, L.J., D.B. Rowe, and B.M. Cregg. 2013. Evaluation of vegetable production on extensive green roofs. Agroecology and Sustainable Food Systems 37(4):465-484.
• Additionally, Green Roofs for Healthy Cities offers a half day course on Rooftop Agriculture: Introduction to Rooftop Urban Agriculture (http://www.greenroofs.org/index.php/education/halfdaycourses).

References

• Butler, C., & Orians, C. M. 2011. Sedum cools soil and can improve neighboring plant performance during water deficit on a green roof. Ecological Engineering,37(11): 1796–1803.
• Carroll, K. 2013. Personal Communication.
• Durhman, A.K. D. B. Rowe, and C. L. Rugh. 2007. Effect of Substrate Depth on Initial Growth, Coverage, and Survival of 25 Succulent Green Roof Plant Taxa. HORTSCIENCE 42(3):588–595. 2007.
• Durhman, A.K., D.B. Rowe, and C.L. Rugh. 2006. Effect of watering regimen on chlorophyll fluorescence and growth of selected green roof plant taxa. HortScience 41:1623–1628.
• Dvorak, B, and K. Carroll. 2008. Chicago City Hall Green Roof: Its Evolving Form and Care. Greening Rooftops for Sustainable Communities Conference Proceedings, Baltimore, MD.
• Dvorak, B., and A. Volder. 2010. Green Roof Vegetation for North American Ecoregions: A Literature Review. Landscape and Urban Planning 96: 197-213.
• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Bulletin E-3047. Downloaded May 1, 2013 from http://www.hrt.msu.edu/greenroof/PDF/08%20GetterRoweExtensionBulletin.pdf

• Grese, R. 2008. Personal Communication.
• Hawke, R. 2013. Personal communication.
• Kestrel Design Group. 2013. Personal Communication.
• Mandel, L., 2013, EAT UP; The Inside Scoop on Rooftop Agriculture. New Society Publishers: Gabriola Island, BC, Canada.
• Monterusso, M.A., D.B. Rowe, and C.L. Rugh. 2005. Establishment and persistence of Sedum spp. and native taxa for green roof applications. HortScience 40:391–396.
• Rowe, D. Bradley, Kristin L. Getter, and Angela K. Durhman. 2012. Effect of green roof media depth on Crassulacean plant succession over seven years. Landscape and Urban Planning (Elsevier) 104: 310-319.
• Rowe, D.B., C.L. Rugh, and A.K. Durhman. 2006. Assessment of substrate depth and composition on green roof plant performance. Proc. of 4th North American Green Roof Conference: Greening Rooftops for Sustainable Communities, Boston, Mass., 10–12 May 2006. The Cardinal Group, Toronto.
• Snodgrass, E.C. and L.L. Snodgrass. 2006. Green Roof Plants: A Resource and Planting Guide. Timber Press.
• Sutton, R.K.; J.A. Harrington; L. Skabelund; P. MacDonagh; R. R. Coffman; and G. Koch. 2012. Prairie-Based Green Roofs: Literature, Templates, and Analogs. Journal of Green Building 7(1):143-172.

• Sutton, R.; B. Rowe;G. Acomb; J. Lambrinos; P. MacDonagh; R. Hawke. 2012. New Plant Performance for 21st Century Green Roof Ecosystems. Cities Alive Conference, Chicago IL.

• Sutton, R. 2011. Personal Communication.
• Torrance, S.; B. Bass, S. MacIvor and T. McGlade in conjunction with Toronto City Planning Division. No publication year given. City of Toronto Guidelines for Biodiverse Green Roofs. Downloaded May 1, 2013 from http://www.toronto.ca/greenroofs/pdf/biodiversegreenroofs_2013.pdf
• VanWoert, N.D., D.B. Rowe, J.A. Andresen, C.L. Rugh, and L. Xiao. 2005. Watering regime and green roof substrate design affect Sedum plant growth. HortScience 40:659–664.
• Whittinghill, L.J. and D.B. Rowe. 2012. The role of green roof technology in urban agriculture. Renewable Agriculture and Food Systems 27(4):314-322.
• Whittinghill, L.J., D.B. Rowe, and B.M. Cregg. 2013. Evaluation of vegetable production on extensive green roofs. Agroecology and Sustainable Food Systems 37(4):465-484.
• Whittinghill, L.J.; D.B. Rowe, 2011. Salt tolerance of common green roof and green wall plants. Urban Ecosystems 14(4):783-794.

While most of the first extensive green roofs in the US were planted with non-native succulent species, mostly Sedum species, the plant palette for green roofs in the US, and in Minnesota, is rapidly expanding to include many herbaceous plants and grasses.

Species included on the plant lists below may not be appropriate for all projects. Suitability can vary with climate, microclimate, project goals, and maintenance budget. Many of these green roof species have not yet been tested in all of Minnesota. While a considerable number of green roofs has been installed in the Twin Cities area, few green roofs have been installed to date in more northern parts of Minnesota, which have a harsher climate that will be more challenging for green roof vegetation.

See Design criteria for green roofs for guidance on factors that affect green roof plant selection.

Growing Sedums and other Succulent Plants on Green Roofs

Sedums and other succulent plants (INSERT Figure 4.1, caption: Sedums on Target Center Arena Green Roof, Image Courtesy of The Kestrel Design Group, Inc.) are often used on green roofs because they are very tolerant of the dry conditions found on most roofs. Durhman et al (2006) found some Sedum species could survive and maintain active photosynthetic metabolism even after 4 months without water! A few of the hardiest ones for Minnesota are listed in Table 1, but these are only a very small portion of the huge palette of Sedums available on the market. Longer lists of succulents available for green roofs, are available, for example, in:

• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Bulletin E-3047. Downloaded May 1, 2013 from http://www.hrt.msu.edu/greenroof/PDF/08%20GetterRoweExtensionBulletin.pdf
• Snodgrass, E.C. and L.L. Snodgrass. 2006. Green Roof Plants: A Resource and Planting Guide. Timber Press.
• Catalog from Emory Knoll, a green roof plants nursery owned by the authors of the 2006 book about green roof plants by Snodgrass and Snodgrass, catalog can be downloaded from www.greenroofplants.com

Many research studies have studied growth of succulent plants on Midwestern green roofs. Dvorak and Volder (2010) summarized North American green roof vegetation studies published through March 2010. Other studies of succulents on Midwestern extensive green roofs that are not included in the Dvorak and Volder (2010) review include:

• Butler, C., & Orians, C. M. (2011). Sedum cools soil and can improve neighboring plant performance during water deficit on a green roof. Ecological Engineering,37(11), 1796–1803.
• Rowe, D. Bradley, Kristin L. Getter, and Angela K. Durhman. "Effect of green roof media depth on Crassulacean plant succession over seven years." Landscape and Urban Planning (Elsevier) 104 (2012): 310-319.
• Whittinghill, L.J.; D.B. Rowe, 2011. Salt tolerance of common green roof and green wall plants. Urban Ecosystems

14(4):783-794.

Non-native succulent species appropriate for extensive green roofs in Minnesota

Growing native species on green roofs

Many species found in Minnesota’s bedrock bluff prairies have also been found to grow well on Minnesota’s green roofs. Bedrock bluff prairies are prairies with very thin soil layers over bedrock, often found along river bluffs, so plants growing in bedrock bluff prairies are adapted to growing conditions very similar to those found on many green roofs: thin growing medium and high exposure to wind, sun, and drought. (INSERT Figure 4.2: Similarities between bedrock bluff prairies and green roof habitats, image courtesy of The Kestrel Design Group, Inc.) Use of native prairie species on green roofs is controversial, because most prairie species survive droughts by sending roots very deep into the soil to access water from deep down. The shallow growing medium of green roofs does not allow for such deep root growth. However, anecdotal observations in Minnesota, Michigan, Chicago IL and Lincoln NE, suggest that deep rooted native prairie species grow their roots horizontally on green roofs (Kestrel Design Group 2013, Sutton 2011, Grese 2008).

Some studies have found that many native species do not survive on green roofs without irrigation (e.g. Monterusso et al 2005). However, in some projects, even some native species thrive on green roofs without irrigation, or with very minimal irrigation. Since irrigation is needed during the plant establishment period anyway, many green roofs include an automatic irrigation system and can be easily irrigated if needed in times of drought. See task 5 for advantages and disadvantages of irrigating a green roof.

Native species have been planted on at least five extensive green roofs in the Twin Cities area, planted between 2005 and 2009 (See Case Studies for Examples). INSERT Figure 4.3: Native Plants on Target Center Arena Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc.; INSERT Figure 4.4: Native Plants on Minneapolis City Hall Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc.; INSERT Figure 4.5: Native Plants on Phillips Eco-Enterprise Green Roof, Minneapolis, MN, Image Courtesy of The Kestrel Design Group, Inc. Table 2 lists some of the native species that have performed well on green roofs in Minnesota (Kestrel Design Group observations). Because all of these except for one are irrigated regularly, the ability of most of these species to survive without irrigation on extensive green roofs in Minnesota is not known. Species that have been found to survive with little or no irrigation in Minnesota or elsewhere in the Midwest are noted in table 2.

Many of the species listed in table 2, as well as many additional native species not listed in table 2, are also thriving on other Midwestern extensive green roofs, including, for example, Chicago City Hall (Dvorak and Carroll 2008, Carroll 2013), Chicago Botanic Gardens trial green roofs (Hawke 2013), and several other green roofs in Chicago, Toronto, and Lincoln NE. The Chicago City Hall green roof, installed in 2001 had 200 species as of 2012, most of which are natives. Its plants are grown in varying depths of soil (some extensive and some intensive), and regularly irrigated (Dvorak and Carroll, 2008). The Chicago Botanic Garden has 2 trial green roofs, installed in 2009, one of which is planted with natives. It includes planting depths of 4”, 6” and 8” of growing medium. Aiming to minimize green roof maintenance, they have watered the green roofs only during extreme drought (beyond establishment): once in 2011, and once in 2012 (Sutton et al 2012).

Dvorak and Volder (2010) summarized North American green roof vegetation studies published through March 2010, including those with native species.

Other publications of Midwestern green roofs planted with native species (not listed in Dvorak and Volder’s 2010 literature review) include:

• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Extension Bulletin E-3047. Downloaded May 1, 2013 from http://www.hrt.msu.edu/greenroof/PDF/08%20GetterRoweExtensionBulletin.pdf
• Sutton, R.K.; J.A. Harrington; L. Skabelund; P. MacDonagh; R. R. Coffman; and G. Koch. 2012. Prairie-Based Green Roofs: Literature, Templates, and Analogs. Journal of Green Building 7(1):143-172.
• Sutton, R.; B. Rowe;G. Acomb; J. Lambrinos; P. MacDonagh; R. Hawke. 2012. New Plant Performance for 21st Century Green Roof Ecosystems. Cities Alive Conference, Chicago IL.
• Torrance, S.; B. Bass, S. MacIvor and T. McGlade in conjunction with Toronto City Planning Division. No publication year given. City of Toronto Guidelines for Biodiverse Green Roofs. Downloaded May 1, 2013 from http://www.toronto.ca/greenroofs/pdf/biodiversegreenroofs_2013.pdf

Not all the species listed in the table below are native in all parts of Minnesota. To find out in which parts of Minnesota these species are native, see Plant species range maps from the Minnesota Department of Natural Resources. For additional information on the species listed in the table below, including wildlife and other benefits, see [2].

Native species that have been grown successfully on extensive green roofs in Minnesota

Growing non-native perennials and grasses on green roofs

While some drought tolerant non-native perennials would be expected to thrive on extensive green roofs, to our knowledge very little if any green roofs in Minnesota have attempted to grow perennials on extensive green roofs.

Growing edible plants on green roofs

Many vegetables and herbs also thrive on green roofs, many in growing medium as little as four inches deep, such as, for example, herbs, tomatoes, peppers, and lettuce. Because they are annuals, vegetables require considerably more maintenance than other extensive green roof plants. If they are fertilized, they will likely increase nutrient content of runoff from the roof, so they may not be ideal for stormwater projects where leaching of nutrients is a concern. If all runoff from the green roof is harvested and re-used on the roof, fertilization will not affect down stream water bodies.

Aside from growing food in a built in place green roof, food can also be grown in containers or hydroponically on a green roof, or on a green or living wall.

The St Paul, MN, fire station is a premier local example of growing food on a green roof. Many other examples of growing food on residential and commercial green roofs can also be found in the US and Canada, including

• Brooklyn Grange, a one acre (43,000 square foot) farm in Queens rooftop farming and intensive green roofing business located on two roofs in New York City, which grows over 40,000 lbs of organically-cultivated produce per year (http://www.brooklyngrangefarm.com/aboutthegrange/
• Eagle Street Rooftop Farm 6,000 square foot green roof organic vegetable farm located atop a warehouse rooftop owned by Broadway Stages in Greenpoint, Brooklyn (http://rooftopfarms.org/)

Several on-line references provide more detail about rooftop agriculture, including, for example, Guide to Setting Up Your Own Edible Rooftop Garden, Published by Alternatives and the Rooftop Garden Project, 2008, downloaded 04/15/2013 from http://archives.rooftopgardens.ca/files/howto_EN_FINAL_lowres.pdf

Other recent publications on rooftop agriculture include

• Mandel, L., 2013, EAT UP; The Inside Scoop on Rooftop Agriculture. New Society Publishers: Gabriola Island, BC, Canada.
• Whittinghill, L.J. and D.B. Rowe. 2012. The role of green roof technology in urban agriculture. Renewable Agriculture and Food Systems 27(4):314-322.
• Whittinghill, L.J., D.B. Rowe, and B.M. Cregg. 2013. Evaluation of vegetable production on extensive green roofs. Agroecology and Sustainable Food Systems 37(4):465-484.
• Additionally, Green Roofs for Healthy Cities offers a half day course on Rooftop Agriculture: Introduction to Rooftop Urban Agriculture (http://www.greenroofs.org/index.php/education/halfdaycourses).

References

• Butler, C., & Orians, C. M. 2011. Sedum cools soil and can improve neighboring plant performance during water deficit on a green roof. Ecological Engineering,37(11): 1796–1803.
• Carroll, K. 2013. Personal Communication.
• Durhman, A.K. D. B. Rowe, and C. L. Rugh. 2007. Effect of Substrate Depth on Initial Growth, Coverage, and Survival of 25 Succulent Green Roof Plant Taxa. HORTSCIENCE 42(3):588–595. 2007.
• Durhman, A.K., D.B. Rowe, and C.L. Rugh. 2006. Effect of watering regimen on chlorophyll fluorescence and growth of selected green roof plant taxa. HortScience 41:1623–1628.
• Dvorak, B, and K. Carroll. 2008. Chicago City Hall Green Roof: Its Evolving Form and Care. Greening Rooftops for Sustainable Communities Conference Proceedings, Baltimore, MD.
• Dvorak, B., and A. Volder. 2010. Green Roof Vegetation for North American Ecoregions: A Literature Review. Landscape and Urban Planning 96: 197-213.
• Getter, K.L.; Rowe, D.B. 2008. Selecting Plants for Extensive Green Roofs in the United States. Michigan State University Extension Bulletin E-3047. Downloaded May 1, 2013 from http://www.hrt.msu.edu/greenroof/PDF/08%20GetterRoweExtensionBulletin.pdf

• Grese, R. 2008. Personal Communication.
• Hawke, R. 2013. Personal communication.
• Kestrel Design Group. 2013. Personal Communication.
• Mandel, L., 2013, EAT UP; The Inside Scoop on Rooftop Agriculture. New Society Publishers: Gabriola Island, BC, Canada.
• Monterusso, M.A., D.B. Rowe, and C.L. Rugh. 2005. Establishment and persistence of Sedum spp. and native taxa for green roof applications. HortScience 40:391–396.
• Rowe, D. Bradley, Kristin L. Getter, and Angela K. Durhman. 2012. Effect of green roof media depth on Crassulacean plant succession over seven years. Landscape and Urban Planning (Elsevier) 104: 310-319.
• Rowe, D.B., C.L. Rugh, and A.K. Durhman. 2006. Assessment of substrate depth and composition on green roof plant performance. Proc. of 4th North American Green Roof Conference: Greening Rooftops for Sustainable Communities, Boston, Mass., 10–12 May 2006. The Cardinal Group, Toronto.
• Snodgrass, E.C. and L.L. Snodgrass. 2006. Green Roof Plants: A Resource and Planting Guide. Timber Press.
• Sutton, R.K.; J.A. Harrington; L. Skabelund; P. MacDonagh; R. R. Coffman; and G. Koch. 2012. Prairie-Based Green Roofs: Literature, Templates, and Analogs. Journal of Green Building 7(1):143-172.

• Sutton, R.; B. Rowe;G. Acomb; J. Lambrinos; P. MacDonagh; R. Hawke. 2012. New Plant Performance for 21st Century Green Roof Ecosystems. Cities Alive Conference, Chicago IL.

• Sutton, R. 2011. Personal Communication.
• Torrance, S.; B. Bass, S. MacIvor and T. McGlade in conjunction with Toronto City Planning Division. No publication year given. City of Toronto Guidelines for Biodiverse Green Roofs. Downloaded May 1, 2013 from http://www.toronto.ca/greenroofs/pdf/biodiversegreenroofs_2013.pdf
• VanWoert, N.D., D.B. Rowe, J.A. Andresen, C.L. Rugh, and L. Xiao. 2005. Watering regime and green roof substrate design affect Sedum plant growth. HortScience 40:659–664.
• Whittinghill, L.J. and D.B. Rowe. 2012. The role of green roof technology in urban agriculture. Renewable Agriculture and Food Systems 27(4):314-322.
• Whittinghill, L.J., D.B. Rowe, and B.M. Cregg. 2013. Evaluation of vegetable production on extensive green roofs. Agroecology and Sustainable Food Systems 37(4):465-484.
• Whittinghill, L.J.; D.B. Rowe, 2011. Salt tolerance of common green roof and green wall plants. Urban Ecosystems 14(4):783-794.