En Espa—ol

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
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
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

Herbicide use in bluebonnet field in Blanco, TX
April 10, 2012 - Dear Mr. Smarty Plants, I have the best of both worlds and the worst of both worlds. Iíve been throwing bluebonnet seeds for 6 years on our property near Blanco, and when it rains, as it has this year...
view the full question and answer

Erosion Control for a NC Clay Slope
June 06, 2013 - Hi, We have a large slope on the road edge of our property that has been gradually eroding with spring rains (NC red clay). We would really like to plant something for erosion control but the bank is...
view the full question and answer

Plants for a sandy slope in NY
April 18, 2011 - I can really use your help. I have a steep very, very sandy slope I need to plant to stop the erosion. It gets sun from 9:00 to 2:00. I plan on adding an irrigation system in the area. Planting is goi...
view the full question and answer

Native Plants for Galveston
February 12, 2012 - I'm looking for low maintenance, drought tolerant plants for Galveston, on the bay side, in a well drained area with morning sun. I was thinking of Phlox, Muhly grass, Lantana.....and I am looking f...
view the full question and answer

What to do about grass dying under pin oaks in Iowa
December 10, 2008 - We have 2 pin oaks about 15 years old in our front yard. The grass has started dying out under and around them. What can we do?
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center