Native Plants
![](../_images/smarty_plants.gif)
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.
Did you know you can access the Native Plant Information Network with your web-enabled smartphone?
Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.
![](../_images/mr_smarty_plants_logo_web_200w.jpg)
rate this answer
![](../_images/star_43.gif)
Saturday - October 25, 2008
From: Austin, TX
Region: Southwest
Topic: Invasive Plants, Non-Natives
Title: Getting rid of giant ragweed in Austin
Answered by: Barbara Medford
QUESTION:
How can I get rid of a large field of giant ragweed? Part of the site is a steep slope, which is difficult to mow. I want to encourage native grasses but they are crowded out by the ragweed.ANSWER:
The best information we could get on Ambrosia trifida var. texana (Texan great ragweed) after doing some research is to allow perennial plants to crowd out this annual. Yeah, right.
So, here's the plan. Get them before they go to seed. And really get them-either cut off the seeding part or pull out the whole things. They're blooming now (thus all the allergies all over town), and once they've bloomed, they set seed. Birds love the rich, oily seeds for winter food, so you're going to make some birds unhappy, but if you don't want a fresh field of new Giant Ragweed next year, those plants have got to go before the seeds ripen. This is not to say they won't come back, because the birds are going to pick up seeds in the field next to yours, and deposit them for you. But if you can slow it down to the point that you recognize them when they're young and yank them out then, long before they even produce the flowers and pollen and sneezes, then you're at least gaining.
Most of the native grasses you are interested in are, indeed, perennials and will, given half a chance, begin to dominate the area, but the ragweed, although annual, is just so numerous that it can shade out the perennial grasses and seriously damage their growth. So, there you have it - you're going to have to do it the hard way, and mid-October is a real good time to start. If you wait until they die back in cold weather, they will have already deposited millions of seeds in the ground, and be all ready to go next year.
More Invasive Plants Questions
Death of non-native eleaegnus from Austin
March 30, 2013 - We have a long hedge of elaeagnus, about 5 ft tall. Four of them died in the middle of the hedge. Where can we find such big plants? Is it advisable to unroot and transplant from another area?
view the full question and answer
Distinguishing native Celastrus scandens from non-native C. Orbiculatus from Lexington MA
June 08, 2014 - Dear Mr. Plants,
I maintain a wildflower garden with the Lexington Field and Garden Club in Lexington, Massachusetts.
Every year, I pull up sprouts of Celastris orbiulatis. I want to plan...
view the full question and answer
Plants that will do well in a water retention basin in White Stone Virginia
May 23, 2011 - I am looking for plants to grow under pine trees in a water retention basin. The pine trees line the basin. When it rains it will hold water for about two to three days before evaporating. I have p...
view the full question and answer
Weeds in Buffalograss from Edmond OK
September 20, 2012 - We have a patch of buffalograss surrounded by patio/flower garden/vegetable garden. We like B-grass, but are getting a lot of weeds despite preemergents, and some bermuda had appeared.
Are there h...
view the full question and answer
Use of non-native pothos for outside wall from Las Vegas NV
January 05, 2014 - I am in Las Vegas, NV. I live in a cottage-style apartment so I have a north facing porch with no one on the west so I get some there (and have an inherited cactus probably a yard all round)
I would ...
view the full question and answer
Support the Wildflower Center by Donating Online or Becoming a Member today. |