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?


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

Sunday - September 07, 2008

From: Rapid City, MI
Region: Midwest
Topic: Non-Natives
Title: Invasive, non-native Cirsium arvense in Michigan
Answered by: Barbara Medford


I have identified that I have growing abundantly "Canada Thistle";the noxious and invasive. I know this to be true because where it grows nothing else grows; not even the native weeds. I want to get rid of it!!!!! Can you direct me as to how I may do this? I have tried pulling it out before it seeds; burning it and cutting it down and it always seems to return in a vengeance!!


We do sympathize, that is one nasty weed. However, there is no magic formula for getting rid of it. Refer to this Plant Conservation Alliance Alien Plant Working Group paper on Cirsium arvense for some  information on the plant. As a non-native plant, it doesn't fall into our ordinary realm of experience at the Lady Bird Johnson Wildflower Center, but as an invasive, we are certainly interested in controlling it. The plant is native to temperate regions of Eurasia, and was introduced to North America, probably accidentally, in the 1600's. Another resource is this University of California at Davis website on Canada Thistle, with instructions on identification and control. We neither recommend for nor against use of pesticides, and urge you to use them with caution, following the directions carefully. One of the points that site made is that it can be more damaging in cooler parts of North America, which would include Michigan. We wish you well in exterminating a really bad pest.  


More Non-Natives Questions

Identification of insects on crepe myrtle in Florida
May 22, 2013 - I have large colonies of striped bugs on large crepe myrtle in my backyard. They stay in large groups and have long antennae. There are larger black bugs among the groups that appear to corral and g...
view the full question and answer

Non-native, invasive mimosa trees in Vincennes IN
April 29, 2014 - I have 3 Mimosa trees here in Vincennes, Indiana and so far none of them are leafing out this spring (4-28-14) Do you think that this past winter could have killed then?
view the full question and answer

Care of non-native Oleander
June 11, 2008 - I want my oleanders to bloom but they keep getting attacked by tiny orange aphids that clump up on the newest growth. I read that oleanders only bloom on old growth but those orange mites/aphids are ...
view the full question and answer

Care of a sedum indoors
December 16, 2007 - I have a coworker who has trusted her Sedum Burrito plant into my care because it is not doing well in her office. It appears to need repotting, as it is very crowded in the pot it came in and is dif...
view the full question and answer

Problems with non-native cuphea in Pearland TX
November 09, 2009 - I have about 8 Bat Face Cupheas and I am having trouble with them. First, instead of mounding 360 degrees, the branches all grow forward (they do bloom well). They're in full sun, about 3 feet out fr...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center