Explore Plants

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
    
 

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

Thursday - April 07, 2011

From: Mt. Pleasant, TX
Region: Southwest
Topic: Grasses or Grass-like
Title: Removing Purple Top Tridens out of Mt Pleasant Texas
Answered by: Leslie Uppinghouse

QUESTION:

We would like to know how to kill these Purple Top Triden out of our garden. Thanks, Judy

ANSWER:

We are guessing that you are looking to remove Tridens flavus (Purpletop tridens) out of a formal garden situation, because this grassy gem is highly coveted by Texans and a great native grass to add to the landscape. We will first talk about all the plusses with this grass in case you have a change of heart.

Purpletop tridens are lovely visually in mass from late summer through the fall. It is light, moves with the wind and has a deep pink color at the top. A great grass for a shady location as it is as happy in the shade as it is in the sun. Tridens hold the ground in place even in sandy soil and can take harsh soil conditions as in clay loam. A good grass for a leach field or areas that are hard to keep pretty. It does not require much water and if you look over the growing conditions in the link, you will see that it is listed as preferring dry soil. 

Livestock will consume it, so if you need it mowed, borrow your neighbors goat. A great hiding grass for nesting birds and also a favorite of many butterflies. A key larval host to skippers and wood nymphs.

Back to your original query. Tridens are not easy to get rid of. It holds the ground in place well, due to its fibrous and rhizomatous root system. Remove the grass now before the late summer seeding. As it is a perennial grass, the seed from last year has already set and the new grass should be showing. Now is the time to dig it up. 

You need to dig it out carefully. Be thorough enough to collect all of the roots and not leave behind the rhizomes. The goat idea isn't really as much of a joke as it sounds. One of the advantages of having a goat handle the first round of trimming is that the animal will consume any seed left on the grass. This would be a better option than mowing it down with a mower and then digging it out. If you don't have a goat handy, then dig it out tall but be careful not to shake out any seed still left on the plant from last season.

After you have dug everything out, if you feel confident that you have been thorough, till the dirt up then comb through the dirt again with your hands and pull out any small roots that have been left behind. Do not skip the digging step and head straight for the tiller. If you do, you risk chopping up the rhizomes and spreading the grass, rather than removing it.

Anytime you have to do any real digging, work smart, not hard. Wait for a good rain or water the area the night before you take on the project. You need the soil loose enough for you to remove all of the plant material without breakage. Having the soil moistened will make your life a lot easier enabling you to complete the task faster. Before you toss the Tridens out for good, look around your property for an area that has been hard to plant or a slope that could use some stability, it really is a very nice grass.

 

 

More Grasses or Grass-like Questions

Green wall panel for Dallas
August 21, 2007 - We are working on a green wall panel for a hotel near SMU--I see your list of recommended species for green roofs, & wondered if you have any ideas for vertical applications. Probably will have someth...
view the full question and answer

Plants to slow water runoff in Austin
April 16, 2011 - What native plants (rocky northwest Austin) will block water runoff? It seems as if something deep-rooted and densely growing would help. Grass comes to mind, but the area gets at best 2 or 3 hours of...
view the full question and answer

Grass for Seattle Arboretum
May 20, 2012 - I am writing to you on behalf of the Arboretum at South Seattle Community College Arboretum. I am interested in Panicum virgatum Switch Grass as a plant for a very heavy clay garden in our Arboretum a...
view the full question and answer

When should I plant bermuda grass seeds?
February 10, 2010 - When should I plant bermuda grass seeds?
view the full question and answer

Grasses for a prairie in southeast Texas
September 30, 2013 - We have a small place (about 100 acres) in Colorado County, Texas, on the Colorado River north of the town of Weimar. We are gradually clearing (bulldozing) the woods of cedars. One particular spot ...
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.