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
1 rating

Friday - August 01, 2008

From: Bozeman, MT
Region: Rocky Mountain
Topic: Invasive Plants
Title: Wild mustard growing in disturbed ground in Montana
Answered by: Barbara Medford

QUESTION:

I have recently planted "plugs" of wildflowers in beds throughout my yard. Because the soil was disturbed, I now not only have some beautiful wildflowers growing, but also mustard plants growing in the wildflowers. And lots of them! Do I need to weed out the mustard plants this year? Or will they die back naturally and the wildflowers will take over next year? Will they compete with the wildflowers for moisture and light? Do I need to even worry about mustard plant invading my beautiful wildflowers? Thanks-

ANSWER:

First of all, it took us a while to discover just what plant wild mustard is. There are so many common names and synonyms for it that it was very confusing. However, we finally established that Sinapis arvensis is the common weed that is most likely infesting your garden. The first thing we want to say is YES, get rid of the mustard plants and do it quickly, because now is the time they are seeding out. They are very difficult to get rid of because they have establish a long-lived seed bank of their own. Pull them out and dispose of them so that their seeds will not spread. Apparently, they generally only show up in disturbed ground, as you pointed out, but although they are native to the Meditteranean area, they now show up all over the world, and appear in all states of the United States, including Hawaii and Alaska. They are classified as a noxious invasive in several western states. They are said to be poisonous to livestock once their seedpods are formed. Many of them harbor an eelworm that attacks other crops, therefore it is best not to grow them in a garden setting. In a word, they've got to go.

Wild mustard is considered a winter annual, which means it will bloom and seed in cool weather, but in Montana, it may very well do so in the Summer. See this website from the University of Missouri Extension on wild mustard.

The wild mustard not only will shade out and crowd out your other plants, but their seed distribution will only make the problem worse. They will not "die back naturally". They are annuals just as most of your wildflowers are, but you need to stop them before they seed. They are not altogether unattractive and if a few get by you and bloom next year, that's not a disaster. But don't let them seed.

Images of Sinapis arvensis.

 

More Invasive Plants Questions

Removing St. Augustine, replacing with native plants
October 06, 2007 - Hello Mr. Smarty Plants, always excited to talk to the Green Guru himself. I've recently purchased a house in South Austin and am interested in establishing a small, 500+ sq ft, prairie grass and wi...
view the full question and answer

Difference between invasive Chinese and Japanese wisterias and native wisteria
September 12, 2014 - Dear Mr or Ms Smarty Plants, Is there any way I can tell for sure if my wisteria is native? I bought it at a place when it was in bloom that sold a lot of native plants. I Would like to know for sure...
view the full question and answer

Identification and replacement of chinaberry tree (Melia azedarach)
April 24, 2007 - I am trying to identify and locate a native tree. We live in Fairview, near Allen, Texas. It is in bloom now. It has fragrant small lavender 5 petal flowers in clusters. They develop into yellow/t...
view the full question and answer

Non-native, invasive creeping fig in Webster TX
May 26, 2013 - We've recently moved into a new home in the southeast Houston area. The back of our property has a long concrete wall (gets quite a bit of sun), which we thought we could cover with a spreading vine....
view the full question and answer

Shade ground cover under honeysuckle from Wichita KS
February 21, 2012 - Hi! I know this is a bit odd, but I am trying to find a nontoxic, good ground covering plant that can live in the shade while competing with the roots of a whole bunch of honeysuckle. I have a few ide...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP | STAFF
© 2016 Lady Bird Johnson Wildflower Center