There is a bag of grass seed that has become a permanent fixture in our office. It was bought a couple of years ago as a prize for a Wellness Committee fitness contest. The sorry thing was never given out because somebody read the label and noticed it contained: 87.7% annual ryegrass, 9% perennial ryegrass, 1.5% other crop seed, 1.5% inert matter, and 0.3% noxious weed seed. It then lists the weeds you’d be innoculating into your lawn if you planted the contents of the bag. In this case, annual bluegrass, hairy chess, and curly dock. We work too hard battling noxious weeds in this Department – there was no way we were going to encourage someone to sow more!
Weed seeds have been hitchhiking with desirable seeds for centuries. Something like a third of Oregon’s noxious weeds are thought to have arrived as seed contaminants. It all starts with weeds in the seed fields. The seeds of the weeds get harvested right along with the seeds of the crop. Yellow starthistle, spotted knapweed, dodder, and whitetop have been spread around as seed contaminants. In this day and age, seed cleaning removes a lot of weed seed, but not all of it. Last year in our laboratory, 190 seed lots out of 6,529 (3%) tested failed because of weed seed contamination above allowable thresholds. This week, our lab has processed 43 seed lots. Weed seeds were found in six of them, though infestation levels were below thresholds, so off they went into commerce – weed seeds and all.
Buyer beware. If you buy cheap seed, you’re likely to get the weedy stuff. We should all make a habit of buying good quality, clean seed. Read the label, including the fine print. If you buy cheap weedy seed or untested seed, you’ll probably pay for it later. The US Forest Service (USFS) learned this lesson the hard way.
In 1988, the Tepee Butte fire burned 66,000 acres in Hells Canyon National Recreation Area. Following the fire, the USFS reseeded the burned area by air, including some adjacent private land. The following spring, they discovered the seed had been contaminated with yellow starthistle. Not only did the Forest Service have to spend a considerable amount of money cleaning up their own land, but the private landowner sued and won a six figure settlement. Ouch!
Oregon’s seed law related to weed contamination needs work. The weed seed tolerances (OAR 603-056-0205) were adopted in 1983 and last revised in 1996. Three years later, Oregon’s noxious weed list was adopted as a regulation (OAR 603-052-1200) preventing importation and selling of noxious weeds. This second regulation has been updated almost every year as new weeds are added. The weed seed and noxious weed regulations have never matched and continue to diverge. It makes no sense.
We’ve got work to do. In the meantime, you can help by reading the fine print on seed packages and not sowing more weeds. We’ve got enough already, thank you!