Pretty Weeds in Paradise: Ribbon Grass on the Metolius

Ribbon grass along the Metolius River in central Oregon. Photo by Maret Pajutee.

Are there weeds in paradise? Are they pretty?  I’m afraid so. I think I saw them there recently. I love central Oregon, and one of my favorite spots is the headwaters of the Metolius River near Camp Sherman. It is an extraordinarily beautiful place.

Clear, cold water fed by snowmelt from the Cascades springs from a hillside, forming an instant river. Large trout tempt fly fishermen as the river winds through pine forests and meadows past Camp Sherman and on to Lake Billy Chinook. The snow-covered slopes of Mt.Jefferson provide a stunning backdrop.

Recently, after hiking up BlackButte, our group stopped at the Camp Sherman store and bought food for a picnic. We sat down along the river to eat. It was shirtsleeve weather, the scenery was postcard beautiful, and the only bugs were mayflies that the fish were having for dinner. Paradise couldn’t be any nicer; even the grass was pretty -- it was an attractive green and white.

Ribbon grass in front of store on Metolius River. Photo by Maret Pajutee.

As I was soaking up the scenery and eating my salmon burger, it dawned on me that there was something peculiar about the grass. It looked out of place. The rest of the riverside vegetation seemed to belong to the pristine riparian habitat, but the variegated grass stood out like a new Corvette at an antique car show. Once I started looking around, it was everywhere. We hiked downstream for a mile and saw that 6-ft diameter clumps where scattered up and down both banks and on all the islands. A few patches were as big as the cabins nearby.

I pulled up a sample to take to the office for identification, but it wasn’t necessary. Crossing back over the Camp Sherman Bridge, we spotted a small sign pointing out a ribbon grass solarization project. The US Forest Service (USFS) and local teens pulled up the ribbon grass on an island just below the bridge, covered it with landscape fabric, and replanted native sedges. There is a short video describing the project at: http://www.ktvz.com/news/27303106/detail.html

US Forest Service work team handpulling ribbon grass. Photo by Maret Pajutee.

While I applaud the Forest Service for their project, the potential of the demonstrated method doesn’t match the scale of the problem. Walk down the river and you’ll see what I mean. There is a lot of ribbon grass, and it’s displacing the native vegetation and growing out into the river. According to the sign, it first showed up in 2003, so it’s spreading fast. It looks like a classic riparian noxious weed invasion, but it isn’t. Here is why.

Ribbon grass is an ornamental variety of reed canary grass, Phalaris arundinacea. You can probably buy it at your local garden store. The OregonAssociation of Nurseries’ Nursery Guide lists three wholesale nurseries that carry it. Regular reed canary grass (same species, different variety) is a valuable hay and forage species in some situations and is not today considered to be a noxious weed in Oregon.

This creates an awkward situation. An ornamental grass is taking over the banks of one of the premier trout streams in Oregon. It is changing the scenery, and it has to be changing the ecology. Local biologists recognize the problem and see it getting worse, but the Forest Service has to comply with National Environmental Policy Act rules that severely limit control options. All the while, the average fishermen and the general public are oblivious to the invasion. If someone did want to clean it up, people would likely oppose the use of herbicides, given the sensitivity of using chemicals in places where people like to recreate. Other options have been tried (pulling and covering) with limited success. Pulling is probably worse for the ecology of the river because it stirs up lots of sediment. Covering isn’t any better as it kills everything under the plastic – neither are practical given the extent of the invasion and both would require working in the river, which is quite dangerous due to strong currents that can sweep people under fallen logs.

The situation is not out of hand - yet. We have a window of opportunity, and we have the tools to repel this invasion. Pete Schay, with Friends of the Metolius, has demonstrated that aquatic formulations of Rodeo and Habitat work well, especially after the first frost. He’s eliminated the ribbon grass on almost all the private land in the area with no adverse effects to the fish or other wildlife. The ribbon grass that remains is on public land managed by the Forest Service. The Forest Service has been trying to get approval to use herbicides on the Deschutes National Forest for a decade. Maret Pajutee, USFS Ecologist, told me that sensitive issues related to the Metolius are holding up the Environmental Impact Statement. Meanwhile the ribbon grass keeps spreading.

Ironically, if it wasn’t a variegated variety, it wouldn’t look so out of place. This weekend I was biking on the Banks-Vernonia State Trail. Reed canary grass was common on the trail margins. It looked great, and the only thing it was competing with was Himalayanblackberry! Reed canary grass and ribbon grass -- Dr. Jekyll and Mr. Hyde; it is an interesting case.

We’re lucky to live in this beautiful state with special places like the Metolius. Ribbon grass is invading that piece of paradise. Is that acceptable? We all have a stake in this – it’s our public land. Should we do something or not?  What do you think?  

Dan Hilburn