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Forage and Turf Grass Seed

Grass Seed and Oregon

Oregon is the world’s number one producer of cool-season forage and turf grass seed. Much of the state’s grass seed is grown in the Willamette Valley where the mild and moist winters and dry summers provide ideal growing conditions.

Turf grass seed is planted for home lawns, athletic fields, and golf courses. Forage grass seed is planted for pastures, road sides and erosion prevention. Grass seed is one of the state’s top commodities. The industry employs approximately 10,000 people annually and generates about $1 billion of annual economic activity in the state.

History of the Grass Seed Industry

Farmers have been growing cool season grass seed in the Willamette Valley since the 1920s. Ryegrass, which is especially well adapted to the valley’s wet soils, soon became an important economic crop. Farmers in the area quickly recognized that grass seed was an excellent crop for the valley’s often poorly drained soils.

Since 1940, the industry has steadily expanded due to new grass varieties, and improved farming methods and equipment. Today, many national and international seed companies are located in the Willamette Valley.

A combine from 1955 in Marion County

Where it is Grown

Most of Oregon’s 1,300 grass seed farms are in the Willamette Valley, especially in Linn, Marion, Polk and Yamhill counties. In fact, Linn County is often called the “grass seed capital of the world.” By acreage, roughly 50% of the Willamette Valley farm land consists of grass seed farms.

The Willamette Valley’s mild, wet winters and dry summers provide an ideal environment for growing cool season grasses. Oregon is one of the few places in the world where farmers are able to harvest seed directly out of the field and place it into storage. Seed harvested in other parts of the world contain more moisture and has to be artificially dried before it can be stored. This drying process reduces the quality and germination rate of the seed and excess moisture makes the seed prone to fungus.

There are three other large grass seed producing regions east of the Cascades. These include the Lower Columbia Basin, the LaGrande area, and in central Oregon around the town of Madras. In these areas winters are colder and precipitation rates are low, therefore, most grass seed farms in these areas require irrigation. Statewide, as much as 500,000 acres are used to grow grass seed.

How Grass Seed is Grown

When a perennial, a plant that lives for longer than two years, grass field is being planted for the first time, and will be in production for many years, farmers take great care to make sure the field is properly prepared and weed free. Weed control is important to the health and profitability of a grass field because farmers are able to get more money for a crop with no weed seeds, and the field will have higher yields.

Soil tests are taken to measure the field’s pH levels. Lime may be added to raise the pH levels. The heavy rain in Western Oregon soils can cause the soil pH level to drop and become too acidic for grass plants.

The next step is to prepare the field by tilling it and using herbicides, a substance that is used to destroy unwanted vegetation, to make the best seed bed possible. After the soil is tilled and loosened, it is checked for pH and other nutrient levels. Once this is done, the planting can begin. Planting occurs in both fall and spring depending on the variety. Varieties that are planted in the fall can start growing in the winter when the rains.

A grass field is carefully prepped and rid of weeds before it is planted

Carbon Banding

A planting drill is used to put the seed and fertilized into the soil. To help control weeds, farmers use carbon band seeding. Carbon banding is where a slurry of activated charcoal is sprayed over the rows where the seeds have been drilled. Next, an herbicide is sprayed over the entire field to control weeds prior to the weeds or grass seed germinating. The charcoal over the drill row adsorbs the herbicide and allows the grass crop to emerge unharmed.

Once the grass is established, additional herbicides may be used to control both volunteer grass seedlings and broad leaf weeds. Grass fields are typically fertilized with nitrogen, phosphorus, and potassium in March and April.

Rusts and other diseases are serious problems in some grass seed species and fungicides are used to help control them. These diseases that can plague grass seed crops can have their biggest impact on seed yield.

Grass seed farmers grow different varieties of grass to protect themselves from a poor crop. Rain or hot and freezing temperatures that hurt one type of seed may actually help a different variety produce more seed. Farmers may lose money on one variety at times, but hope to make money on another.

Carbon banding is used to control weeds in newly planted fields


Sheep are sometimes used to graze the forage grass seed fields. Grazing is like pruning a tree. Wherever a blade has been cut off, the plant puts up more shoots. The more shoots, the more seed a plant will produce. The animals graze on the fields during the winter months through March.


Two other creatures that feed on grass fields are geese and slugs. They can destroy crops in a matter of days. They eat the grass and roots, leaving nothing, but a poor crop and mud.

Typical black garden slugs are a major pest to grass seed fields

Swamp Buggies

Since very few places grow grass seed the equipment they use must either be modified or manufactured by the dealer or farmer. Swamp buggies were created to apply fertilizers and chemicals on wet fields. A swamp buggy has huge, balloon-like tires that can move across the wet fields without leaving ruts. Since grass seed is grown mostly on wet soils, swamp buggies can go on fields during the winter and spring months when normal tractors would sink in the mud.

The large balloon tires on swamp buggies let farmers work in fields too wet for tractors


Harvest time for grass seed crops begins in late June or early July. A machine called a windrower or swather cuts the grass and lays it in rows. This is done while the grass seed is still somewhat green to prevent it from shattering. Seed shattering is a natural way seeds are dispersed.

The grass then dries in the sun and wind for 5-10 days before being harvested. A combine separates the seed from the straw and spreads the straw back on the field. The seed is then transferred from the combine to trucks and transported to the seed cleaning warehouse.


Windrows of grass drying in the sun before being harvested


A combine picking up dried windrows and separating seed from straw

Combine and Truck

Harvested grass seed is put into trucks that will haul it to the seed warehouse for cleaning and storage

Cleaning Seed

seed cleaner is used to remove the soil, weeds and small pieces of straw from the tons of harvested grass seed. The cleaner has several screens which move back and forth inside the cleaner and the good seed falls through the screens. The bigger pieces of weed and straw are left on the top screen. The bottom screen is finer and only the dirt and tiny weed seeds fall through. The good seed is left on top of the last screen.

A seed cleaning warehouse, where seed is cleaned, bagged and labeled

Seed Certification

After cleaning, the seed is bagged and sampled for germination and purity. The price a farmer gets for the crop depends on how well the new seeds grow and if it contains any weed seeds. The definition of a weed is any plant where it is not supposed to be. So, if the crop is suppose to be ryegrass and the test shows Orchardgrass, then it has a lower value.

Many growers use the Seed Certification Service at Oregon State University or other private labs to test their seed. The certification program helps assure buyers the seed they buy is of a high quality. To meet certification standards, a grower’s field must pass a seedling inspection, a crop inspection prior to harvest, and cleaned seed must meet germination and purity requirements.

A seed certification service inspects fields to evaluate if seed is genetically pure. The grass must be planted in rows so inspectors can easily check for weeds. These inspections are timed so off-type seeds, other crops and weed contamination, can be easily detected. The inspector looks for evidence of volunteer plants, weeds or other problems that could cause problems in the genetic purity of the seed. Before each harvest, the crop is again inspected, usually when the plants are in the final stages of seed formation.

Certain harvesting practices must be followed to meet certification standards. If there are strips along the edges of a field that could be contaminated genetically by nearby fields, these must be harvested separately and seed lot records must be maintained for each lot. These isolation strips can only be sold as less profitable uncertified seed. Field equipment must also be cleaned when fields of different growers are harvested.

Finally, a sample from each harvested seed lot is tested for germination and mechanical purity by visual inspection.

The label on the package of seed lists the type of seed it contains, the germination rates, and the origin

Post-Harvest Residue Management

Residue is the remaining straw and stubble after the grass seed is harvested. In the mid-1940s open-field burning was a way growers controlled disease problems (ergot, blind seed, and seed gall nematode) and pest like rodents and slugs. Field burning was also used to dispose of straw following seed harvest. However, during the 1970s and 1980s this practice became increasingly controversial and as of 2010 is no longer an option.

Today, farmers have two options when it comes to removing residue. The first is baling the straw and remove it from the field. Baling is when the straw is tightly bundled up and secured with wire or cords. The baled straw can be used for animal feed, and there is a huge export market for baled straw to Asian countries. The other option is to let the straw decompose in the field. The straw composts, which adds nutrients back into the soil for the next year’s crop.

The bale wagon collects bales of grass straw to sell them as animal feed and bedding


As farmers adjusted to reduced field burning, a new export market developed for the straw. Over one billion pounds (600,000 tons) of grass and grain straw is now exported annually to Japan, Korea and Taiwan for dairy and beef cattle feed. These exports sales have an estimated value of $50-$60 million.

Grass seed has many uses. Forage grass is used in pastures for cattle and other livestock to graze on, roadside plantings, and is often used to help stop soil erosion. Turf grass seed is used for soccer and other types of sport fields, and is used on the fields of premier sporting events including the Super Bowl, World Cup Soccer, the Olympics and major golfing events. The straw from both types of grass is baled and sold for livestock feed.

Grass Species

There are many different kinds of grass seed and each type is used for a specific location and purpose.

Oregon’s Willamette Valley produces nearly all the ryegrass seed grown in the United States. In fact, nearly one half of the nation’s ryegrass seed is grown in Linn County.

Annual ryegrass
Annual ryegrass seed

(forage grass) It is a fast growing forage grass planted along roadsides and other areas requiring quick, economical ground cover. Annual ryegrass is often used on hillsides to curb wind and water erosion problems.

Perennial ryegrass is used for turf and pastures
Perennial ryegrass

(turf and forage grass) This is the most widely used grass in the world. It is used in the northern states for permanent turf and forage pastures and for overseeding of dormant grasses in the southern U.S. It has been cultivation as a forage grass since the 17th century.

Tall fescue is a popular pasture grass
Tall fescue

(turf and forage grass) This is a popular grass in the transition zone between northern cool-season grass species and warm-season southern species.

Bentgrass is widely used at golf courses

(turf grass) Oregon produces nearly all the Bentgrass seed grown in the United States. Predominantly a Willamette Valley crop, Bentgrass seed is exported in large quantities to Europe and the central and northern states for use in turf mixtures. This grass is widely used on golf courses throughout the world.

Fine Fescue

This group of grasses is used for golf courses. It grows well in shaded areas and is very drought tolerant.

Kentucky bluegrass is a common turf grass
Kentucky bluegrass

(turf grass) In Oregon this grass is only grown in Union and Umatilla counties and in the Madras area. It is widely used as a turf grass in the cooler climates in cities and rural communities.

Orchardgrass is used for pastures in northern climates

(forage grass) This grass is used in the northern states for pastures and grass hay. Oregon is the nation’s leading producer of orchard grass seed and it is most commonly used for cattle feed.

Vocabulary Terms

to bundle up straw and secure it with wire or cords

a slurry of activated charcoal that is sprayed over rows of planted seed to help control weeds

a piece of equipment that separates the seed from the straw and spreads the straw back on the filed during harvest

planted for pastures, road sides, and erosion control

a substance that is used to destroy unwanted vegetation, like weeds

other crops and weed contamination in a grass seed field

a plant that lives longer than two years

the remaining straw and stubble after the grass seed is harvested

a machine with several screens that removes soil, weeds, and small pieces of straw from the harvested grass seed

the natural way seeds are dispersed, through wind, touch, and animals

special equipment designed to apply fertilizer and chemicals on wet fields without sinking into the field

planted for home lawns, athletic fields, and golf courses

an plant where it does not belong

also called a swather, it cuts the grass and lays it in rows to be dried

AITC Resources

Oregon Quality Grass Seed
Oregon Quality Grass Seed

High Yield Grass Seed Production and Water Quality Protection Handbook
High Yield Grass Seed Production and Water Quality Protection Handbook

Turf Buddies

Oregon Seed Council Booth Video
Oregon Seed Council Booth Video