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
Not Yet Rated

Friday - June 26, 2009

From: Austin, TX
Region: Southwest
Topic: Invasive Plants, Problem Plants
Title: Eliminating crabgrass in a newly mulched area in Austin
Answered by: Barbara Medford


We just had our whole front lawn taken out. We are starting to plant native plants in its place. The idea was to do whatís best for the environment and reduce maintenance. At this point Iím beginning to wonder if it was a good idea. All over, through the mulch, crabgrass has started sprouting massively (in just a few days since the lawn was removed). I could grow a crabgrass lawn. I tried moving the mulch aside and digging the roots out but they are at least 2 inches deep and holding on very hard, also they break so I know new plants will come out in a couple of days again. I donít want to use Round Up. That seems against the point. Besides, we live on a greenbelt so Iíve always tried not to use chemicals as much as possible. How can I control the crabgrass without spending time I donít have in the yard?


Probably offering you our deepest sympathy is not going to suffice, is it? Actually, the word is that when you are trying to rid an area of weeds, rototilling (which you didn't say you did) is not the way to go, because you just pull more seeds and roots to the surface where they can germinate.  But, even if you took it out with a sod cutter, obviously the Digitaria texana (Texas crabgrass) arose again. And it's probably no comfort that this USDA Plant Profile map shows it growing only on the Texas Coast. There is also, of course, Digitaria arenicola (sand crabgrass) (only on southern tip of Texas), Digitaria cognata (fall witchgrass) (widely distributed from Texas east and into eastern Canada, and Digitaria hitchcockii (shortleaf crabgrass), found in the  Big Bend area, South Texas and, you guessed it, Travis County. This is information you don't need and won't help, it is all basically the same, and very difficult to get rid of. 

To be honest, we're stalling because we really don't know the answer to your question. One thing we have realized is that crabgrass is an annual weed, with shallow roots. Starve it of light and water, don't let it go to seed, and it should be gone. Of course, you will always get seeds from other places, but if you are vigilant and pull it out as soon as it appears, that can be minimized. We found a website from One-Stop Tree and Lawn Care with a section on crabgrass that had some good suggestons. From the Home Improvement News and Information Center, read this article Prevent or Eliminate Crabgrass in Your Lawn. From the website All About Lawns, read the 10 Steps to Become Crabgrass Free. 

Finally, since it really is too hot to be planting much in the way of native plants, or anything else for that matter, you might consider this article on Soil Solarization from  Arid-Southwestern Gardening Information. Perhaps an area you are not ready to plant yet, but where lawn was and crabgrass is would be a good candidate for this. 

We agree with you on avoiding the chemicals in your crabgrass warfare. You don't want to risk contaminating your soil nor take the chance of accidental damage to nearby desirable plants. We think continuing to mulch and hopefully shade out the crabgrass, pulling out what does emerge, and never allowing it to go to seed (which it will do all season), although labor-intensive, is the best and most environmentally friendly way to go. 

And to be sure you know your enemy, here are pictures of crabgrass. 



More Invasive Plants Questions

Fighting Sandburs with Bluebonnets in Austin, Planting Bluebonnets in Caliche soil
September 22, 2010 - Mr. Smarty Plants, In my continuing fight against sandspurs I've decided that if I plant a copious amount of bluebonnets seeds that the foliage will choke out the sandspurs because bluebonnets set...
view the full question and answer

Brown, dry leaves on weeping willow tree
May 01, 2008 - We live in central TX and have just planted a weeping willow tree. Our back yard has a retention pond and ravine that parallels our property and we were told that the weeping willow will do perfectly ...
view the full question and answer

Care for a Campsis radicans in Yakima, WA
October 08, 2008 - I have a Campsis radicans it is in a 7" pot and the plant is 20" tall. It was a clipping given to me by a lady that is now out of town. My question is: I live in zone 6a so do I leave it in the p...
view the full question and answer

Sandbur invasion in Mission TX
June 08, 2011 - I have a spiny sandbur invasion in my yard. Even the dog tiptoes around to do her business. Because I live in Mission, TX, this weed acts like a perennial and is constantly growing (no winter freezes...
view the full question and answer

Skunk cabbage for Houston TX
September 19, 2009 - Can you find skunk cabbage in the Houston, Texas area?
view the full question and answer

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