En EspaŅol

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
Not Yet Rated

Tuesday - November 20, 2007

From: Rockledge, FL
Region: Southeast
Topic: Grasses or Grass-like
Title: Trimming of cordgrass plants
Answered by: Barbara Medford and Joe Marcus

QUESTION:

We have planted more than 150 cordgrass plants (spartina bakeri) along the edges of the small pond at our condominium complex to try to prevent any further soil erosion between the buildings and the pond. The majority of each plant has turned brown with some green within them. They are anywhere from 2 1/2 to 3 feet tall and about the same in width. Our "pond doctor" says they should be cut back 6-12 inches from the tips. The person who sold them to us says "Don't touch them!" Two other credible (degreed) sources (different businesses)said to cut them back to 4 to 6 inches above the root base since it will allow for greater growth and a fuller plant next year. Lastly, the "authority" from the state says "Leave them alone because cutting them back will interfere with the photosynthesis process." The disagreement among these "educated sources" has created quite a dilemma in that we don't know whether they should be cut or left alone. The people of knowledge are so differing in their opinions that we don't know whom to believe. HELP!!!

ANSWER:

Spartina bakeri (Sand cordgrass) does not appear in our Native Plant Database; however, it is native to Florida and naturally grows in marsh and wetland areas. Refer to this Floridata website for more comprehensive information. If it has only grown to 3 feet tall, it has some growing yet to do, as it grows from 3 to 5 feet. It's a beautiful grass, and well chosen for the location you have described. Pruning or trimming it, on the other hand, is a fresh can of worms.

We can certainly understand those who do not wish to see it trimmed at all, because of its natural beauty. But, we agree that it could get out of hand; sand cordgrass has the potential to become invasive, as it is an aggressive, spreading plant. And, it's not going to be particularly fun to trim it-while it's blades are long and rough, like sandpaper, on the upper edges, it is not sharp. But wading into 150 cordgrass clumps with a pair of pruning shares is not an attractive prospect. At the Lady Bird Johnson Wildflower Center, as you may know, we grow a number of grasses (as well as many other plants) native to North America. There is no particular policy on trimming grasses here, but every couple of years or so we try to clean out the dead grass in a clump, partly for purely aesthetic reasons, as our gardens are display gardens, but also because the dead grass, in a drouth period, can become a fire danger. One suggestion was to trim every other plant several inches one year, and the others the next. And we don't feel they need to be trimmed down to little "meatballs" of 4 to 6 inches high. That's pretty labor intensive, and you're probably going to end up with some sort of compromise, depending on who is going to be doing the trimming, and what appears the most attractive.

Oh, and photosynthesis. Okay, there is some justification to worrying about that, if you were, say, going to mow the cordgrass down to lawn height. Photosynthesis is the conversion of light energy into chemical energy by living organisms. The raw materials are carbon dioxide and water, the energy source is sunlight, and the end products include glucose and oxygen. When plant experts are advising on pruning back a plant, they usually advise not pruning more than 1/3 to 1/2 of the upper structure, in order to leave the leaves (or blades, as it were) in sufficient numbers to manufacture food to sustain the plant. So, if you cut off a few inches or 1/3 of the height, you will leave plenty of material to photosynthesize. And cleaning out the dead and dry stuff makes more sunlight available to the plant to continue the process.

In the final analysis, we don't have a conclusive answer for you, either. We do recommend keeping the grasses cleaned up of dead material, we do think it contributes to the plant health to trim it some but not frequently, and we do urge that you be aware of both the invasive tendencies of the grass and the fire danger of dead and dry grasses.

 

More Grasses or Grass-like Questions

Groundcovers for Miami, FL
November 10, 2011 - I live in Miami, Florida. I have a medium size Bismarck Palm in my front yard. What would be a good ground cover other than grass around this palm?
view the full question and answer

Native grass lawn for San Antonio
June 25, 2011 - Dear Mr Smartyplants, I live outside of San Antonio and my question is in regards to putting in a native grass lawn. What type of soil should I put down? I've sprayed herbicide and was planning on ...
view the full question and answer

Advice on grasses under walnut trees
May 28, 2010 - Little advice on grasses: I am prepared to plant zoysia under two walnut trees. Forgot about juglone-is this a good idea?
view the full question and answer

Native wildflower habitat for North Carolina
January 24, 2007 - I am from North Carolina and have been gradually establishing a wildflower spring garden. I now have a beautiful display of bluets and cornflowers that grace my front yard in the spring. Most of this...
view the full question and answer

Ornamental bunch grasses to grow under live oak
June 25, 2007 - I love live oak trees and have one in the back yard that is growing nicely. I don't know if it's the shade or the leaf and acorn droppings that won't allow the grass to grow underneath it. Around...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center