Saturday, May 26, 2012

Adopt-a-Weed Report, May 2012

It’s been a productive weed-pulling season in Ogden’s foothills.

Our most visible weed is dyer’s woad, with its upright stalks topped with a head of yellow during May. Ridding the foothills of this invasive plant may seem hopeless, but the Ogden Sierra Club has made a significant dent by “adopting” a 10-acre area above the 22nd Street trailhead and returning there to pull the dyer’s woad each spring. If I’ve counted correctly, this was our eighth year working in this area, and I’m delighted to report that we’ve made great progress. The plants do keep coming back, but they’re much thinner than before. This year it took only two hours for four of us to cover the entire area. (I went back for another half hour, a week later, to get the late bloomers.) In coming years we should be able to expand our adopted area to the north and/or south.

Most of Ogden’s trail users now seem to be aware of the dyer’s woad problem, and many will pause along a hike to pull a few plants. But to make real headway against this weed, our “adoption” method—spending a few hours working the same area each year—seems to be the key. I hope more groups will try it.

Meanwhile, two years ago I learned about myrtle spurge, a weed that’s still far less widespread than dyer’s woad but well established in a few dense infestations. One of those is at the 27th Street trailhead, and I personally adopted it two years ago. The strategy was to start pulling plants at the perimeter of the infestation and gradually work inward, containing and reducing the affected area.

Follow-up is also crucial with myrtle spurge, but it’s much easier because the plant grows more slowly than dyer’s woad. It’s taken me only about an hour each season to pull the small plants that are trying to come back in the areas that are already purged of mature plants. Now, after three seasons of work, the infestation is reduced to a single patch between the westernmost trail and a resident’s fence.