Explore Plants
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.
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
Tuesday - May 01, 2012
From: West Lake Hills, TX
Region: Southwest
Topic: Invasive Plants, Non-Natives, Plant Identification, Problem Plants
Title: How Can I Tell an Invasive Thistle from a Native
Answered by: Mike Tomme
QUESTION:
Mr Smarty Plants, I have some thistles coming up in my yard. I'd like to keep them if they are native, but not if they are invasive or non-native. How can I tell? My yard is a wild area in West Lake Hills, TX.ANSWER:
It would seem you have asked a simple question, but in reality you haven't. As you can see from this previous Mr. Smarty Plants answer, there are quite a few different plants that occur in central Texas that can be called some sort of thistle. As this answer makes clear, it can be difficult to tell the natives and non-natives apart and it requires a fair amount of research.
To help simplify mattes, I am going to assume that the thistles in your yard are the ones with the pink/lavender flowers that are blooming all around central Texas at this time of year. If you have the ones with yellow or white flowers, go back to that previous answer.
In her book Wildflowers of Texas, Geyata Ajilvsgi includes two thistles with pink/lavender flowers which I take to mean they are among the most common. They are:
Cirsium texanum (Texas thistle) - As you would guess from its name, this is a native thistle
Carduus nutans (nodding thistle) - This is a non-native. It is listed as an invasive plant by both Texasinvasives.org and the USDA. Another common name for it is musk thistle.
These are very similar in appearance. I sought help with identification methods from Minette Marr at the lady Bird Johnson Wildflower Center and she suggested a article published by the Oklahoma Cooperative Extension Service at Oklahoma State University entitled Thistles in Oklahoma and Their Identification.
From the Image Gallery
More Problem Plants Questions
Controlling poison oak or poison ivy in Iowa
April 29, 2010 - We recently purchased a property that is VERY wooded and has been vacant for two yrs. with little upkeep previously. We have (we were told) l00 yr old poison oak vines hanging
from trees. We hired so...
view the full question and answer
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
Black Walnut tree in LA
March 12, 2012 - I was just given a black walnut tree and am trying to determine where to place it. I’ve read on your site that “Certain plants will not grow under Black Walnut trees because of the juglones that the ...
view the full question and answer
Eradication of invasive thistles in Parma OH
July 11, 2010 - Lawn is full of prickly weeds with very deep roots. May be called Scotch Thistle, although id is not confirmed. They will grow as tall as they can amid other plants, and when mowed in the lawn, they...
view the full question and answer
Controlling sedge in vegetable garden in Mississippi
August 03, 2008 - I have a veg. garden surrounded by Purple Sedge. The nut grass has been contained/eliminated by replacing all dirt 1' down. Now the surrounding sedge is beginning to creep inward infesting the gard...
view the full question and answer
 |
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. |
