En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Fighting Sandburs with Bluebonnets in Austin, Planting Bluebonnets in Caliche soil

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

Wednesday - September 22, 2010

From: Austin, TX
Region: Southwest
Topic: Invasive Plants
Title: Fighting Sandburs with Bluebonnets in Austin, Planting Bluebonnets in Caliche soil
Answered by: Mike Tomme and Barbara Medford

QUESTION:

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 foliage in the late fall and early winter and will choke out any sandspur seedlings before they can take hold in the spring. Is my logic super flawed? What is the likelihood that bluebonnet seeds planted in September will flower in March when planted in caliche soil?

ANSWER:

Mr. Smarty Plants would never tell you that your logic is flawed. However, Mr. Smarty Plants doesn't think your idea will work. Sandburs (aka sandspurs, grassburs and a bunch of unprintable names) are just too tough. A little bit of shade and crowding won't stop them. They'll just grow right up through the bluebonnets and the two will thrive together. Think of the fields of bluebonnets you've seen and how, late in spring when the bluebonnets fade, the grasses come right back. Sandburs are a grass and they will do the same.

The sandbur you have is most likely Cenchrus spinifex (Coastal sandbur). This plant grows throughout the southern United States and Mexico. It favors poor soils, like caliche, and does well in recently disturbed areas. 

Control of sandburs is is most reliably achieved by hand pulling and, in the longer run, by improving the soil by adding organic matter and eliminating compaction. For hand pulling, learn to recognize sandburs when they have not yet produced the burs, or seeds, so you can pull them out as the opportunity arises. Here is a site that has more information about control of sandburs.

As for your question about planting bluebonnets (Lupinus texensis), early October is the best time to plant seeds. Bluebonnets do well in caliche soils. Here is a how-to article on growing bluebonnets.


Cenchrus spinifex

 

More Invasive Plants Questions

Landscaping large area in Webster KY
February 10, 2012 - We just bought a house that we fell in love with. The land around it . . . well it has GREAT potential but is seriously lacking at the moment. Trying to get the farm up and running leaves very litt...
view the full question and answer

Trees to replace some non-native invasives in Deltona FL
February 02, 2012 - I would like to replace 3 large ChinaBerry & 3 large Chinese Tallow trees in my good sized back yard with some local wildlife friendly trees native to the Deltona area(first area.) What do you recomme...
view the full question and answer

Managing non-native invasive creeping yellow cress in Rio Medina TX
January 10, 2012 - Due to my lawn mower dying and waiting for the shop to fix it my yard got a bit overgrown. I was walking around the yard looking at the blooming wildflowers and have discovered that one of them is Ror...
view the full question and answer

Invasive non-native mulberry and groundcover in Jacksonville FL
October 02, 2011 - Northeast Florida (Jacksonville) inland. My mulberry tree provides dense shade in the summer and filtered light the other seasons, leaving sand in its growing area. What fast growing ground cover woul...
view the full question and answer

Non-native Royal Empress tree with only green leaves from Chambersburg PA
July 12, 2013 - I have 3 Royal Empress trees in my yard that are between 2-4 yrs old and have never been any color other then big Green leaves. Do you know when they will turn Purple?
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