Grass Seed
Willamette Valley Grass Seed Production
Oregon is the world’s major producer of cool-season forage and turf grass seed and a widely recognized center of expertise in seed production. Most of the acreage is located in the Willamette Valley, the “grass seed capital of the world.” Farm gate value of Oregon’s production for the last several years has been historically low. Farm gate sales for 2010 were estimated to be $228,464,000. Collectively, Oregon’s Willamette Valley produces almost two-thirds of the total production of cool-season grasses in the United States (U.S.).
Grass seed is produced on nearly 1,500 grass seed farms in Oregon. Seed production of one or more grass species are the major enterprises, with growers using machine technology especially adapted to small seeds. Mild and moist winters with dry summers favoring seed development and harvest make the Valley an ideal place to produce high quality seed. Over 390 seed conditioning plants located in the Willamette Valley prepare the seed for market once the harvest operation is complete.
Prior to World War II, farms in the Willamette Valley were more diversified and smaller than farms today. Grass seed was introduced as early as the 1920s as an alternative crop for the south valley. Ryegrass was especially well adapted to the wet soils and soon became an important crop. Grass seed also established itself as an excellent alternative crop for the highly erodible foothill soils found on the valley’s eastern flank. Since 1940, the industry has made steady growth, with many national and international seed companies located in the Willamette Valley.
The Willamette Valley’s mild, wet winters and dry summers have provided an ideal environment for the grass seed industry to expand. Grass seed crops are grown on more than half of the total harvested cropland in the Willamette Valley. In 2010, Oregon growers produced over 592 million pounds of cool-season grass seed crops. Today, seed crops of over 950 varieties from eight grass species are grown on over 375,000 acres statewide. Of these, 347, 000 acres are located in the Willamette Valley.
Oregon growers produce essentially all of the U.S. production of annual ryegrass (Lolium multiflorum Lam.), perennial ryegrass (L. perenne L.), bentgrass (Agrostis spp.), and fine fescue (Festuca spp.). Smaller amounts, but significant portions of the USA production of Kentucky bluegrass (Poa pratensis L.), orchardgrass (Dactylis glomerata L.), and tall fescue (Festuca arundinacea Schreb.) are also grown in Oregon.
For more information on grass seed produced in Oregon and the Willamette Valley:
Seed Production Research Reports
Publication: Using Seed Moisture as a Harvest Management Tool
Video: Using Seed Moisture as a Harvest Management Tool
Nutrient Management
Nutrient Management in Grass Seed Crops
Before planting a grass seed crop, test soil for pH, phosphorus, potassium, calcium, magnesium, and lime requirement. Add and incorporate material before planting.
Nitrogen is needed by all grass seed crops. A small amount, of fall nitrogen is recommended for tall fescue. For perennial ryegrass, fall nitrogen is not required. A small mount of fall nitrogen, 30 to 40 lb/a, and can be applied and used to reduce spring nitrogen rate.
Most of the N is supplied in the spring from mid-February to mid-April in two to three applications or “splits”. Nitrogen application rate varies for grass species. Fine fescue requires the lowest rate, 30 to 70 lb/a and perennial ryegrass the highest, 120 to 160 lb/a. Refer to fertilizer and nutrient management guides for each grass species for specific nitrogen rate information.
Straw removal by baling removes a substantial amount of potassium. Monitor soil test potassium where straw is baled. Click here for more information on nutrient amounts and value in grass straw.
Click on the following links to view related OSU Extension Publications:
Postharvest Residue Management for Grass Seed Production in Western Oregon
Nutrient Management for Annual Ryegrass Grown for Seed
Fertilizer Guide: Tall Fescue Grown Grown for Seed
Fertilizer Guide: Orchardgrass Grown for Seed
Fertilizer Guide: Perennial Ryegrass Grown for Seed
Fertilizer Guide: Fine Fescue Grown for Seed
Soil Test Interpretation Guide
Weed Management
The OSU Weed Science Group conducts greenhouse, laboratory and small plot herbicide evaluation trials in support of the development of weed management activities in the diverse cropping systems of Western Oregon. Labeled and experimental herbicides are evaluated for crop safety and weed control efficacy in the following crops: Winter and Spring Wheat, Cool-season Grasses grown for seed, Native cool-season Grasses and forbs grown for seed, Canola, Meadowfoam, Camelina, Clovers and Peppermint among others.
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Annual Bluegrass |
Roughstalk Bluegrass |
Rattail Fescue |
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California Brome |
Sharp Point Fluvelin |
Annual Sowthistle |
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Mayweed Chamomile |
Catchweed Bedstraw |
Prickly Lettuce |
Weed Science Related Links:
Weeds of California and Other Western States
PNW Weed Management Extension Publications Series
Oregon Society of Weed Science
Western Society of Weed Science
Weed Identification Resources:
Weed Science Society of America
Center for Invasive Plant Management
Herbicide Labels:
Disease/Insect Management
Grass Seed Diseases
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Stem RustUSDA Stem Rust Model |
Stripe Rust |
Choke |
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Stripe Smut |
Rynchosporium Scald |
Blind Seed |
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Ergot |
Rathay's Disease |
Brown Stripe |
Grass Seed Insects
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Orchardgrass Billbug |
Cutworms |
European Crane Fly |
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Sod Webworm |
Garden Symphylan |
Grey Garden Slug |
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Winter Grain Mite |
Wireworm/Click Beetle |
March Fly |
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Grass Thrips |
Meadow Plant Bug |
Army Worm |