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

White evening primrose from Baton Rouge LA
April 16, 2013 - My husband and I have a disagreement about Mexican Primroses. I believe I have seen patches of them which are pure white. He believes they must be faded pink ones. Do white ones occasionally grow? ...
view the full question and answer

Nutgrass in Lakeway TX Habiturf
September 30, 2012 - I just installed a new septic system with drip field. Planted habiturf over the whole area. The habiturf is doing good, but I was away for a while and the nut grass has taken over several areas. It s...
view the full question and answer

Something to grow under a chinaberry tree
August 29, 2008 - I have a huge Chinaberry on the west side of the house. We enjoy the shade it provides and have it limbed up pretty high, but it's located between two 2-story houses and of course drops buckets of it...
view the full question and answer

Eradicating Campsis radicans in Kissimee FL
January 07, 2011 - I am interested in information on eradicating or controlling 'cow itch' [campsis radicans?] which is spreading on an empty lot of land adjacent to an occupied dwelling. It is causing significant dis...
view the full question and answer

Native alternatives for invasive species
April 05, 2011 - I'm a native plant landscape designer in central Texas, and know our plants well. Still looking for any help I can get on replacements for Asian jasmine, English ivy, Nandina, and Red tipped photin...
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