Rent Shop Volunteer Join

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
6 ratings

Wednesday - July 22, 2009

From: Baltimore, MD
Region: Mid-Atlantic
Topic: Rain Gardens, Compost and Mulch, Grasses or Grass-like
Title: Native plants for a bioswale in Baltimore
Answered by: Barbara Medford

QUESTION:

What native plants would suit a bioswale in an urban part of Baltimore City? The clay soil gets waterlogged and the site has part shade.

ANSWER:

Mr. Smarty Plants is not THAT smart, and can always learn something new. This time we learned about bioswales. Common swales are typically vegetated with turf grass and are a conveyance tool, basically a grassy stormwater sewer that conveys water as quickly as possible from Point A to Point B. A bioswale differs in that the turf grass is replaced with native prairie vegetation. This will significantly reduce the flow velocity (slow down of the runoff) in the swale’s drainage course. The residence time of the runoff is thus increased, which gives it the time to be stored, filtered, and infiltrated. These processes remove pollutants and suspended solids from runoff.

In terms of your clay soil, we found this information on bioswale construction from the USDA, which shows compost tilled into the native soil (clay, in this instance) to facilitate the drainage. The plants we have selected are all perennial, tolerate shade, and will grow in moist, clay soils. These are plants with fibrous roots that will hold in the soil when water is rushing by, help to slow it down, and permit the pollutants in the water to be filtered out. 

Since our suggestions are basically for prairie grasses, you might be interested in reading our How-To Article Recreating a Prairie, which has instructions for time of year to be planting, preparing the soil, planting and caring for the grasses. When you are ready to begin, go to our Native Plant Suppliers section, put your town and state in the Enter Search Location box, and you will get a list of native plant nurseries, seed companies and landscape consultants in your general area who can help you select the right plants for your purpose.

Andropogon gerardii (big bluestem)

Carex blanda (eastern woodland sedge)

Carex hystericina (bottlebrush sedge)

Carex texensis (Texas sedge)

Chasmanthium latifolium (Inland sea oats)

Elymus canadensis (Canada wildrye)

Elymus virginicus (Virginia wildrye)

Sorghastrum nutans (Indiangrass)


Andropogon gerardii

Carex blanda

Carex hystericina

Carex texensis

Chasmanthium latifolium

Elymus canadensis

Elymus virginicus

Sorghastrum nutans

 

 

 

 

 

More Grasses or Grass-like Questions

Tufted hairgrass seed for Houston TX
August 06, 2009 - From Houston-Texas I am looking for a seed grass called tufted hairgrass ( deschampsia caespitosa ), if you can tell me where to find this kind of seed. Thank you for helping.
view the full question and answer

Lawn Options for Saginaw, MI
April 09, 2015 - I'm looking for a low maintenance, high traffic lawn alternative. Will Texas Frogfruit handle the winter? My yard is small so covering it is an option.
view the full question and answer

When to plant grasses on Long Island, NY
December 06, 2009 - Dear Mr. Smarty Plants; Are there any grass seeds that I can plant NOW, early December, on Long Island, NY? The planting environment is on and near a sandy bluff on a bayshore, where it can be windy ...
view the full question and answer

Problems for plants growing over closed loop field of geothermal system
October 22, 2008 - We would like to install a geothermal heating/cooling system on our Wisconsin property. Are there any environmental problems with the heat that is put back in the earth from a geothermal system? We ...
view the full question and answer

Native grasses palatable for horses and eliminating KR bluestem.
January 11, 2008 - Looking for native Texas grasses which are palatable for horses, to overseed in areas which are currently overrun with KR bluestem. What are the best grasses and best way to accomplish this? (SW Gi...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.