I’ve spent several days scanning the Overlook Trail and Montini Preserve properties for the invasive Yellow starthistle (YST). Although it’s still early in its season, it’s clear that it has essentially been eradicated from these two properties. I will still be looking for it this season and next, but I’ve pulled so little so far it seems nearly pointless. After over a decade of fighting this scourge, I expected to be able to celebrate this major accomplishment.
But I can’t.
We’re in the very early days of “Thistle Season,” which sadly lasts from November into August. That’s right, those of us who struggle against thistle get something like 2-3 months off a year. And knowing how relentless invasive species can be, that actually seems generous to this obsessed lunatic. Italian thistle starts coming in as early as the rain does while Yellow starthistle doesn’t come in until much later in the season, like around May and extending into August.
Right now most of the Italian thistle looks totally tiny. Thankfully, I’ve come to recognize Italian thistle as soon as the third leaf comes in. This is because the third (and then later, the fourth) leaf comes in with spikes (see picture). It’s completely unique among the plants found on the Sonoma Overlook Trail and the Montini Open Space Preserve, so you know you have it dead to rights.
And the great thing about pulling Italian thistle now is that all you need to do is to pull it and toss it. Later, when it goes to flower, we will need to bag it up and carry it out. We dump our bags beside the dumpster in Mountain Cemetery next to the City Public Works Yard. Most years the pile gets to be about ten feet in circumference and about five feet high.
But before we even begin to create that pile we’ve pulled thousands of plants and tossed them aside. Starting with the plants that show that tell-tale third leaf.
Today I found an Italian thistle (Carduus pycnocephalus) plant (see picture). It’s the earliest I have found it, with the previous record being November 10th. I fault the early rains we’ve had this month.
What this means is that I will now turn the bulk of my trail efforts to pulling it from along the trail, primarily on the Montini Preserve, where we have yet to push it back. Last year, sadly, I didn’t even get close to achieving that highly desirable result. My hope is to do a lot better this year, which would mean removing all of the trailside plants by about June.
This is going to be a long eight months.
Priscilla, Tom, Roy, Elizabeth, and Kurt. Jamie took the picture.
Yesterday a crew of six stewards, including me, headed out to clear the upper Sonoma Overlook Trail meadow of invasive Italian thistle. We made one complete sweep of the upper meadow and emerged with ten contractor debris bags full of the nasty weed, as well as some remaining invasive Yellow starthistle, which unfortunately was a surprise.
Elizabeth Garsonnin, Priscilla Miles, Jamie Nelson, Tom Sours, and Kurt Teuber came out to help with this important battle. If we hit Italian thistle hard now on the upper meadow, before it completely drops its seed, we have a chance of eventually eradicating it instead of allowing it take over completely.
Although we’ve been largely successful in pushing it away from the trail, we are still challenged in large areas where Italian thistle is gaining the upper hand. On the Montini Preserve, my focus has been simply to get it off the trail, as that is the only reasonable goal for that property at the moment. But on the Sonoma Overlook Trail property, we have an opportunity to eradicate it further back from the trail. Eventually, some years from now, my goal will to be to not even see it from the trail, but that is clearly some years out still, and may never be achieved on the Montini Preserve, where it’s fairly rampant.
Today I went out to assess the invasive Yellow starthistle infestation this year. I’m happy to say that it’s less than last year, but it’s still there. We may still be several years away from complete eradication.
But the really depressing thing to see is that Italian thistle is simply taking its place.
This has me thinking that my strategy needs to be this:
If you wish to join us, let me know! People along the trail are very appreciative of this work.
Sonoma Overlook Trail • Montini Open Space Preserve 