The Yellow Star-Thistle is an invasive species in Texas with a yellow flower and nasty spines. It can grow up to five feet high and does well in areas with dry summers. It’s difficult to remove because of its long tap root.
The Yellow Star-Thistle seeds do not spread with the wind and this means new plants will usually sprout just a few feet away from the parent plant. Traveling animals or people working on roadsides help to accidentally spread the thistle and give its seeds a chance to invade new ecosystems sooner than it naturally could.
For the Yellow Star-Thistle, I was fascinated to learn from the Texas Invasives plant database that six biological control insects have been released in the United States to attack the seedhead of the thistle.
Just a few years ago, Dr. Damon Waitt predicted that the Yellow Star-Thistle would be the next big invasive species to threaten Texas rangelands. (Dr. Waitt is the Senior Director and Botanist at the Lady Bird Johnson Wildflower Center.)
Whether by mowing, hand pulling, insects, or other means, any way that we can reduce the number of seeds that the invasive thistle can produce will help us limit its spread and give us a chance to keep our native ecosystems safe or reclaim areas that have been invaded.
Give the thistle the business on the City of Austin’s wildlands
There’s a chance for you to help rid our native ecosystem of invasive species by removing the star thistle from lands that are used for water quality and recharge with the City of Austin’s Wildland Conservation Division.
Dr. Kevin Thuesen mentioned that the Malta Star-Thistle and King Ranch Bluestem (KR Bluestem) invasive species have been invading Austin’s water quality lands near Onion Creek. (Dr. Thuesen is the Environmental Conservation Program Manager for the Water Quality Protection Land program that is part of the Austin Water Utility.)
The Wildland Conservation Division is also looking for volunteers for other activities on their water quality protection lands. Water that seeps through karst features (big and small cracks and caves under the surface) and from Onion Creek on these lands makes its way to the Barton Springs Aquifer. So helping to maintain the natural ecosystem of this land is important to water quality.
In addition to invasive species removal, here are some of the other upcoming volunteer events in April:
- 4/4 – Star thistle invasive species removal at Reicher Ranch
- 4/11, 4/12, 4/14, 4/15 – Recreation survey to understand trail use
- 4/11 – Seeding the Water Quality Protection Lands after a prescribed burn
- 4/19/, 4/26 Land stewardship to restore endangered species habitat at the Vireo Preserve
I enjoyed the time that I volunteered with Austin’s Wildland Conservation Division. Here are a few of my posts with my past adventures on the Balcones Canyonlands Preserve (BCP) that are part of the City of Austin’s wildlands.
- Adventures with Austin’s Invasive Species Corps
- Insurgent Chinese Privet Attempts Invasive Species Comeback
- Top 5 Invasive Plants Sneaking into the Balcones Canyonlands Preserve
- Titanic Struggle with Chinese Privet Ends with their Doom