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?


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
2 ratings

Sunday - April 25, 2010

From: Myrtle Beach, SC
Region: Southeast
Topic: Non-Natives
Title: Ridding non-native centipede grass of native rattlesnake weed in Myrtle Beach SC
Answered by: Barbara Medford


How do I get rid of "rattlesnake weed" in my lawn of centipede grass in Myrtle Beach SC?


This puts us in a slightly embarrassing position. The Lady Bird Johnson Wildflower Center is dedicated to the use, protection and propagation of plants native not only to North America but to the area in which it is being grown. Your "weed," Hieracium venosum (rattlesnakeweed) is native to South Carolina, while your lawn, Ischaemum muticum, Centipede Grass, is native to China and parts of southeast Asia. Turns out both plants are considered by some to be invasive in nature. One source said that centipede grass can become a weed in many annual and perennial crops and can develop into huge thickets in drainage canals and ditches. 

However, to you the rattlesnake weed is the invasive. We have no personal experience with it (but we do with rattlesnakes!) but from the information we have it looks pretty hard to pull out, which is always our first choice in getting rid of something like that. Preventing it from blooming, so it cannot set more seed, is the first line of defense. As those blooms stand up pretty high off the ground, getting them mowed early will certainly help. 

Much as we hate to prescribe herbicides, because of environmental reasons, that may be your last resort. Centipede grass is a monocot, like all grasses. Rattlesnake weed is a dicot, also classified as a broad-leaf plant. You can buy herbicides specifically for either; obviously, you want one for a dicot, or broad-leaf plant. Read the instructions carefully, and follow them closely. Broadcast spraying could, with a gust of wind, damage some shrubs, flowering plants or trees, because they are dicots, also. 

Conclusion: Prevent the Hieracium venosum (rattlesnakeweed) from seeding if you can, pull it out of the ground when it's possible, use a dicot herbicide as a last resort. But mind the rattlesnakes!

From our Native Plant Image Gallery:

Hieracium venosum

Hieracium venosum

Hieracium venosum




More Non-Natives Questions

Thorns on non-native orange trees
March 04, 2007 - I just moved into a new home that has orange trees in the yard. The tree trunks and limbs are thorny. What kind of oranges are they? How should I care for them? Is it ok to cut off the thorns so t...
view the full question and answer

Care of non-native house plant, probably Coleus
September 16, 2007 - What would cause the new leaves of a house plant to be solid green? When I bought it, the original leaves were almost like a "tie-dye" fabric (green,yellow,orange, and red).
view the full question and answer

Identity of rubbery-looking tree with long green thorns
March 21, 2012 - I am trying to identify a tree that has a green rubbery look with long, sharp, green thorns. This tree is on my property in Conroe, TX and the soil type is Gladwater clay frequently flooded.
view the full question and answer

Problems with peonies in Indianola, WA
May 18, 2009 - My 5 year old peony plant didn't come up. I thought it was dead so I dug it up. I found a clump of thick roots. I separated them, and then realized these were probably the bulbs. It is the middle...
view the full question and answer

Non-native banana trees
June 06, 2008 - I recently planted two types of Banana trees, a Darjeeling and a Giant Nepal. I know that both are hardy to my zone 7 but that the Nepal needed heavy mulching. My first question is how long will it ta...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center