Starthistle. That kind of has a pretty sound to it? Right? Wrong! Yellow starthistle is currently ranked at the top of the state’s noxious-weed list, it is the only weed currently denoted as priority 1A, meaning that if detected it is to be eradicated. Several years ago the yellow starthistle was found in Stillwater county. Since then, state and local officials have been brainstorming on how to eradicate the intruder and its off spring.
In a recent article, State weed director Dave Burch said “From the state’s perspective, that’s our biggest threat. We definitely want to keep that one out of the state. Every time we’ve had a confirmed sighting, we’ve been able to eradicate it.”
In the past 25 years, there have been dozens of reports of yellow starthistle, but the current infestation is the worse. Each plant has potential of broadcasting thousands of seeds. Many fall right by the plant, but with Montana winds, they can be carried quite a ways. This weed patch, which is about 10 acres, is near a sight that stages construction projects, so equipment is always coming and going, spreading the weed to more places. Which is how they figure the weed came to be in Montana, catching a ride on equipment!
So what exactly is so bad about starthistle? Well, let me fill you in. Like many other noxious weeds, starthistle can quickly force out desirable species as it infests rangelands, farmlands and roadsides. Large invasions of starthistle will deplete soil moisture in the equivalent of 15 to 25 percent of the mean annual precipitation of an area. Starthistle also sucks up moisture earlier than competing plants, which causes native species to suffer from drought conditions, even in a good rain year.
The yellow starthistle is less than desirable as a feed source. Cattle, sheep and goats are known to graze on its early green growth, and some bird species feed on its seeds. But the weed is toxic to horses. When they eat the thistle, it attacks their neurological system and the horses end up starving to death, and is refered to as chewing disease. Another bad thing is some horses will seek the weed out to eat.
If you would like to know more check out this article in the Billings Gazette. Or go to MT Weed Control