Q?Can Ryegrass Help Break up Fragipan Soils?

Yes. The deep root system of annual ryegrass is very effective at penetrating compacted  and restrictive layers in the soil. Soil scientists estimate there are 50 million acres of fragipan soils in the U.S.

Q?What is the seeding rate for annual ryegrass?

Between 8 to 30 lbs per acre depending on the seeding method, time of seeding and conditions of the seed bed. (Click here for more specific information. Or click here for a detailed management guide.)

Q?Do I need a grass seedbox on my drill?

No, conventional equipment on your farm can be used. For specific information about types of seed application, click on the “Resources” tab at the top of this page. Under that tab, click on “Publications” and choose “Management Guide.” Or, you can merely click here.

Q?Can I control annual ryegrass in the spring with one herbicide application?

Excellent control can be achieved with a single glyphosate application if an adequate rate of herbicide is used. A second application may be necessary if initial conditions were marginal.

For more specific information, click here.

Q?How do I seed annual ryegrass?

Annual ryegrass can be seeded by drill, broadcast, airflow, airplane or helicopter and in liquid manure. Annual ryegrass is most frequently planted  in the fall, just before or at harvest. But in recent years, more growers in the northern tier of the US and in southern Canada are planting it in the spring, when corn is about knee high.

The goal is to get good seed-to-soil contact and to plant when you have good moisture in the soil or anticipate rainfall. While drilling annual ryegrass seed is the most reliable way to establish a vigorous cover crop, aerial seeding or seeding with a high-boy just before corn or bean harvest is becoming more popular, because of the added time the cover crop will have to establish before winter weather.

Also click on the “Planting Annual Ryegrass” tab (under “Ryegrass” menu)  for more info on seeding alternatives, time to plant and seeding rates.

Q?Are any of your ryegrasses organic?

Most annual ryegrass seed is produced under conventional systems. Organic seed supply is very limited.

Q?My stand is thin and poor, what should I do?

If it is early in fall then be patient, your stand will likely improve. If you experience extreme weather variation in the winter (especially freeze and thaw cycles) you may see some winterkill. Again, patience is important. Even if the cover crop seems entirely brown upon emergence from winter, there may be life in the plant crowns and you can see rapid growth. However, if winterkill has taken the cover crop, don’t be too discouraged. The root growth during the fall is still doing your soil lots of good. And, the residual annual ryegrass plants on the surface will successfully avoid any loss of topsoil in the spring.

Q?If I purchase ryegrass seed but do not use it this year can I store it?

Yes, but ryegrass must be stored in a cool, dry place. If you choose to do so, be sure to get a germination test on the annual ryegrass seed before determining the seeding rate.

Q?Who can I contact if I have additional questions?

There are numerous links to other websites here on this website (click on the Resources tab, most of which have added information on cover crops and annual ryegrass. The Oregon Ryegrass Commission has a staff and will help you find answers if you have difficulty finding them on your own. Click on Contact Us if you have questions.

Q?Do I need to add nitrogen when planting annual ryegrass?

Whether to add more nitrogen depends on a number of things:

  • The amount already in the topsoil
  • How much organic matter is in the soil
  • Whether the field has cover crops or is no-tilled already
  • Whether manure is added as a practice

If N is not present, it’s a good idea to use 30lb/a of nitrogen fertilizer or manure at planting.

Annual ryegrass sequesters available nitrogen in the soil and stores it for later use for cash crops. You can expect that with extended use of annual ryegrass, the need for additional nitrogen inputs will drop significantly.

Q?How does annual ryegrass compare to cereal rye in weed suppression?

Cereal rye provides better weed suppression than annual ryegrass because it exudes chemicals from its roots that suppress weeds (allelopathy). However, with a dense stand of annual ryegrass throughout the winter, it will also act as a good weed suppresser.

Q?Where can I buy annual ryegrass seed?

We do not sell annual ryegrass through this site, nor recommend a particular variety. However there are many sources of annual ryegrass available from seed dealers in your area or direct from growers in Oregon.

Click here for a current list of Oregon seed growers.

Note: ask your dealer if the variety recommended has been “tested in the Midwest for cover crop use (both for winter hardiness and for ease of management).

You can also call the Commission office in Oregon, at 503-364-2944.

Q?Can I harvest my own ryegrass seed?

No, the high humidity and rain frequency in the Midwest precludes economic harvest of ryegrass seed. And, more importantly, when using annual ryegrass as a cover crop, you certainly don’t want the crop going to seed, because of management issues when annual ryegrass would compete with your cash crop.

Q?If I use annual ryegrass this year how much more yield should I expect my corn next year?

Research and farmer experience has shown that the effect of annual ryegrass on corn yield is positive. There are a number of things to keep in mind, however:

  • The benefits of using annual ryegrass as a cover crop are not necessarily immediate if the field is just now being switched over from conventional tillage
  • The longer a cover crop is used, the bigger the yield benefit.

Yield response can vary a lot, depending on the year and the soil in which it is planted:

  • In a survey of more than 3,000 farmers (Conservation Technology Information Center), the average yield increase of corn grown after cover crops was 9.6 percent in 2012 and 3.1 percent in 2013.*

Yield response can be dramatic in a dry year, because annual ryegrass allows crops to reach deeper moisture and nutrients.

*Click here for a 2014 – 15 report from the Conservation Tillage Information Center on the yield impact with cover crops. Look specifically at pages 23 – 27.


Q?How do I know I am purchasing quality ryegrass seed?

In some cases, farmers buy direct from seed growers in Oregon. But if you buy from a coop or other seed dealer, ask them questions about the source of their annual ryegrass seed.

Seed bags should have attached information about variety, purity and viability. In general, seek a named variety that has been used successfully in the Midwest, not a generic variety or a VNS (variety not stated). Oregon has a highly-regarded certification program for all exported seed produced in the state.

Click here for a current list of seed growers in Oregon.

Ask for Varieties that are Midwest Tested

A three year study (2005 – 08) found three or four among 16 tested varieties that were more winter hardy. More are being developed and tested all the time. It’s best that you inquire among those who already have experience with annual ryegrass – neighboring farms, a trusted crop consultant or seed dealer. As there is a wide variety of climactic variation in the Midwest states, New England and southern Canada, there are more factors than there are research dollars to fully investigate.

Research is ongoing at the University of Ohio, University of Missouri, Purdue University and others. As more information on winter hardiness, plant vigor, and ease of control using herbicides, this website will be updated accordingly.

Q?Is annual ryegrass the same thing as cereal rye?

No, annual ryegrass (Lolium multiflorum) is a completely different species than cereal rye (Secale cereale) and has many different attributes. A primary benefit of using annual ryegrass is that it has a more extensive root system than cereal rye. Its roots grower much deeper in the soil, breaking up compaction as it goes.

Also, annual ryegrass has less biomass, or residual, on the surface after it is killed in the spring, thus allowing the sun to reach the soil more easily and allowing a more rapid drying out.