Musk thistles at Bandelier
Following the Cerro Grande fire, my forest hydrologist friend Greg Kuyumjian told me “Keep a watch for the bull thistles, they’ll move in and take over.” And over the years my wife June and I have spent countless hours on the Santa Fe National Forest working as volunteer thistle removers.
The Las Conchas fire in 2011 burned much of Bandelier, and last August June noticed a few roadside musk thistles, another bad plant, just inside the Bandelier boundary along New Mexico Highway 4 outside Los Alamos. We stopped to take a look, totally unprepared for what we saw: at least 10,000 musk, bull, and Canada thistles growing in waves up the hillslope. It was the worst infestation we’d ever seen, certainly the type of thing Greg had warned us about.
We immediately signed on as Bandelier natural resource volunteers, and set out to tackle the problem, only to be overwhelmed by the enormity of the task.
Thistles (in the Jemez Mountains the genera Cirsium and Carduus), are attractive members of the sunflower family of plants. Their “flowers” are really a dense cluster of small, red or purple, tubular flowers held together in a compact head. Each of the hundreds of individual flowers in a head can produce a tiny seed attached to a wisp of feathery bristles that easily disperse in the wind. Light riding little parachutes, the seeds are dispersed nearby in great numbers and can be carried on a breeze for miles. Thistles spread fast over large areas of open terrain, like burned areas.
Scott McFarland, Chief of Resources at Bandelier, offered a small crew of Native American youth to get us back on track. We met them at the site and explained the task at hand. Bull and musk thistles are biennial plants, forming a rosette of leaves their first year, then shooting up spiny, leafy stalks terminating in flower heads. In August, the flowers are in full bloom. If you simply pull up the plant and throw it on the ground, the flowers will go ahead and develop seeds. You must pull or cut off the heads, bag them, and later carry them out of the area. Then you can pull up the plant—if you leave it in the ground, it will likely just make more flower heads.
Nobody enjoys eradicating spiny plants, but the young adults stuck with us until we were all relived to have thunderstorm put a halt to the work. We regrouped the next day, but after two days, we barely made a dent in the thistle population.
It takes more than a handful of people to control thistle populations, and the Friends of Bandelier are working with monument staff and the Pajarito Environmental Education Center to hold two volunteer thistle thwarter work parties at Bandelier in spring 2020. Spring is a much better time to deal with thistles—most have not begun to sprout up, there are no flower heads, and you can just dig them out by the roots. Contact with the spiny leaves and stems is kept at a minimum.
We hope to start the thistle thwarters with a project near the Cerro Grande Trailhead, and follow that in a few weeks with work on the monster thistle patch we started to eradicate last year.
Watch for more information on the Friends web site, Facebook page, or send you email to friendsofbandelier.org to get on the thistle thwarter contact list.