En Español

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 Compost and Mulch Questions

Newly planted magnolia in Hedron NE
September 19, 2010 - We planted a Magnolia stellata 'Royal Star' in our landscape about 2 weeks ago. It is approx 7' tall. My question is should the leaves on it all be turning brown and crisp already or are doing some...
view the full question and answer

Yellowing leaves on non-native weeping birch in Brick NJ
August 16, 2009 - I have a young weeping birch-planted in spring-we water regularly, it gets good sun-and rain has been perfect--the leaves get yellow--and now they are a lot! Whats the matter? I love my little tree.I ...
view the full question and answer

Transplanting Mexican bonebract in Floresville, TX
November 12, 2008 - My kids and I finally identified a small plant that we found growing in our pasture. There was only one and it is lovely. It is the Mexican Bonebract. What I am interested in finding out is how to tra...
view the full question and answer

Soil for native Chilopsis linearis and Salvia greggii
February 08, 2010 - I want to plant a desert willow and a salvia greggii in my small lot. The developer used sandy loam to fill in the small garden in the front. I am 73 and a bit impaired. Do I really need to remove ...
view the full question and answer

Ground cover to withstand dog traffic in Michigan
November 02, 2010 - I need a soft ground cover that will grow in sand, and be able to take four big dogs that love to run in the yard. Grass just doesn't make it. Someone suggested that groundcover might work. Thanks...
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 | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center