Yellow Starthistle (Centaurea solstitialis) on Jul 18, 2010
Submitter has sample
EDRR Status: Local expert notified
Description of specimen
The presently unused schoolground/running track area has been a major yellow starthistle nursery for several years. The School District has mowed the area earlier this year and even sprayed the running track with a broad spectrum herbicide. Unfortunately, they have not mowed the area recently and on my return from out-of-town I found thousands, probably tens of thousands, of blooming starthistle. I pulled perhaps 50 plants from the track, mostly to see if pulling was feasible, and managed to get a complete root from about half the plants that were pulled. It would take a small army of reasonably strong-armed people to remove all of the plants.
Commentary
Expert Reviewer
SWORISN Coordinator
Teresa Fernandez
SW OR Program Assistant
Americorps Conservation Team
The Nature Conservancy
tfernandez@tnc.org
(541) 770-7933 ext. 5#
Reporter
July 18, 2010, 6:30 a.m.
Thank you for your report! We appreciate that you are keeping an eye out for local invasive species populations, especially in significant areas such as schoolgrounds. Unfortunately, yellow starthistle is not listed as an EDRR species because of its extreme abundance in Jackson County and therefore is not prioritized as a species for rapid response within the SWORISN program. If you do not have our list of local EDRR species to look for, I will be happy to send that to you.
Though it is not a high priority for rapid response in this area, we do appreciate your notification regarding this species and we are happy to provide some resources that may be able to answer your question and provide additional information for treating this population.
One helpful resource is the "Element Stewardship Abstract", which can be accessed by following the link http://www.invasive.org/weedcd/pdfs/tncweeds/centsol.pdf
One page 4 of this publication is a general summary of the most effective herbicide use for this plant. A more detailed description of how to effectively control this plant with herbicides is provided on pages 15-17. After quickly scanning the information, it seems the best time to spray is during the rosette stage from late winter to early spring as spraying now would probably not prevent the production of viable seed. However, I will forward your report with your questions on to a local expert to see if I can gather more information and resources regarding this species and effective ways to control it. You can also look for additional resources on the Western Invasives Network Website at http://www.westerninvasivesnetwork.org/.
Once again, thank you for reporting! Please keep up the good work and continue reporting!
Sincerely,
Alicia Fitzgerald
SW OR Program Assistant
AmeriCorps Conservation Team
afitzgerald@tnc.org
(541) 770-7933 ext. 5#
SWORISN Coordinator
July 20, 2010, 9:43 a.m.