En EspaŅol

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?

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
    
 
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 - November 12, 2008

From: Kahului, HI
Region: Hawaii
Topic: Invasive Plants
Title: Invasive introduced sandburs in Maui, Hawaii
Answered by: Barbara Medford

QUESTION:

I live in Maui, Hawaii & I have a serious problem with Cenchrus spinifex and/or Coastal sandbur grass (weed!) it is everywhere, in my flower beds, in my gravel yardscape. Every time I pull it out it drops its very prickly burs that stick to everything and cover the ground, so how do I eradicate it without killing my other plants? The burrs/seeds are all over the ground where I pulled out the grass. How do I prevent them from growing? So frustrated!

ANSWER:

A grass itself, grassbur is a common, troublesome weed in pastures, lawns and other turf areas. This is one of those plants where we must admit a plant native to North America is a pest. Of course, it's not native to Hawaii, but there it's an introduced pest. Either way, you don't want it in your garden.

Grassbur thrives in overgrazed or otherwise struggling turf, especially nutrient-poor turf. Healthy turfgrass will typically outcompete Cenchrus. Improved turf health is the surest strategy for ridding the lawn of grassburs.

You said you were experiencing the sandburs everywhere. To give you some idea of how to develop a healthy turf that will resist the sandbur, read our How-To Article on Native Lawns. Also, here is an article about Sandburs and some possible controls. One disadvantage we have here is that the Lady Bird Johnson Wildflower Center is dedicated to the care and propagation of plants native to North America, which means we are not going to have grasses native to Hawaii in our Native Plant Database. Go to this site from the Maui County Extension Office, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. That webpage has contact information, and possibly they can help you select lawn grasses or ground covers that will crowd out the sandbur.

You really can't prevent the seed (sandbur) from growing. What you have to do is get to the plants before they set seed. You need to learn to recognize the plants when they are juveniles, before they get the burs on them, and get them out of the ground at that stage. Their native habitat is sandy or thicker soils, especially on disturbed ground. So, plowing up an area won't help a bit, it will disturb that soil and make fallow ground for a whole lot more grassburs to plant themselves. You can't spray weedkiller in the flower bed or the lawn, because it will kill the desirable plants, also. You might try careful squirts of a dilute weedkiller on the plants in the gravel yardscape; just be careful to do it on a windless day, so it won't drift onto something you don't want dead. But the main prevention of more sandburs is preventing the seeds from setting. Get them out of the ground first. 


Cenchrus spinifex

Cenchrus spinifex

Cenchrus spinifex

Cenchrus spinifex

 

 

More Invasive Plants Questions

Eliminating dogbane from transplanted milkweed in Franklin Lakes NJ
May 10, 2010 - We transplanted milkweed from the wild into our garden. Included in the clump of milkweed was dogbane. We weren't aware of how invasive dogbane is. We've has some success in digging it out but we'...
view the full question and answer

Ivy for wall cover in Dallas
August 03, 2009 - I am trying to cover older apartments with Ivy to create a beautiful exterior look, but after reading several articles on how the Texas Sun kills Ivy, I would like to know what plant can I use to crea...
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

Non-flowering mimosas in Texas
July 08, 2008 - I have two mimosa trees, about 3 years old. Both were grown from volunteer seedlings. Neither have flowers nor have they produced seed pods. Are they too young or do they need a source of pollenation...
view the full question and answer

Definition of a weed
April 22, 2003 - What is your definition of a weed?
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