Annual Ryegrass
Lolium multiflorum

Also known as: Italian ryegrass

Cool season annual grass


  • Biomass/organic matter source (Dry Matter: 2,000-9,000 lbs/ac/yr)

Very fast establishing cover

Weed suppression

Topsoil conditioner

Nutrient catch crop (high N user)

Plant Highlights

  • EXCELLENT for increasing organic matter and improving soil structure, for providing erosion control, for quick growth and establishment
  • VERY GOOD for taking up & storing excess N, for suppressing weeds, for animal grazing (production, nutritional quality & palatability), for providing lasting residue

Cultural Traits

  • Fair heat tolerance
  • Fair drought tolerance
  • Very good shade tolerance
  • Very good flood tolerance
  • Fair tolerance to low fertility
  • pH range 5.5-7.0 (NRCS), prefers 6.0-7.0 (SAN)


Planting depth: 0 - 1/2 inches

Seeding Method

  • Drilled: Seed at 5-10 lb./A (0.2-0.4 bu/A)
  • Broadcast: Seed at 15-30 lb./A (0.6-1.25 bu/A)

Seed Cost: .50 $/lb

Seed Availability: Readily available


Cultivars commonly recommended by the Hawai`i Natural Resources Conservation Service include: 'Hubam'.


with legumes, grasses

Soil Improvements

  • Good for loosening subsoil
  • Good at releasing P and K
  • Excellent at loosening topsoil

Pest Control

  • Good for suppressing nematodes
  • Good for disease suppression
  • Good allelopathic properties
  • Excellent weed suppression
  • Fair for attracting beneficial insects

Management Attributes

  • Excellent trafficability
  • Rapid establishment and growth ideal for short windows


  • Annual ryegrass may compete with the cash crop for N and moisture when used as a living mulch. Manage it appropriately (especially during drought, prolonged high or low temps, or in low fertility soils) to prevent yield decreases.
  • Can become a weed if allowed to set seed.
  • May tie up N while residue is decomposing. Wait a few weeks after incorporation before seeding subsequent crop or grow with a legume.


Uses in the Pacific Region

No information is available in this database on this topic.

Uses in Hawai`i

The Hawai`i Natural Resources Conservation Service Technical Guide includes Annual Ryegrass (cv. 'Tam 90') and Lolium rigidum (cv. 'Wimmera 62'). Their specification describes Annual Ryegrass as follows:

  • Minimum broadcast seeding rates of 40 lbs. pure live seed/acre;
  • pH range from 5.5-7.0;
  • Approximate growing time 90 days;
  • Approximate dry matter yield 1.5 tons/acre;
  • Approximate N content 13 lbs./T dry matter;
  • Add 25 lbs. of nitrogen/ton dry matter at plow down;
  • Optimum planting period year round at elevations over 1500 ft.
  • Optimum planting period fall/winter at elevations below 1500 ft.

Evensen, Osgood and El-Swaify conducted five years of research with small grains as cover crops on sugarcane plantations for erosion and weed control. Variety trials for 51 cultivars of oat, barley, wheat, ryegrass and rye grain on Hawai`i, Molokai, and Lanai were compared. Of the annual ryegrass trials, varieties 'Alamo' and 'Tam 90' were the most promising (in terms of vigorous growth, rapid soil cover, weed suppression, low plant height, and lack of flowering). This information has applications for pineapple, coffee and tropical fruit tree orchards.

For More Information:

UC Davis On-line Cover Crop Index


Evensen, C.I., Osgood, R.V., & El-Swaify, S.A. Small grain cover crops in Hawaii for erosion and weed control. A poster paper presented at the conference on "Cover Crops, Soil Quality and Ecosystems", March 12-14,1997.

1998. Managing Cover Crops Profitably, 2nd ed. Sustainable Agriculture Network, National Agricultural Library, Beltsville, USA. pp. 212.

USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992. Pacific Islands Area Field Office Technical Guide (eFOTG) - East Area

Text last updated on 9/23/02

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These webpages were originally generated under a grant program from Western SARE entitled "Covering New Ground: Tropical Cover Crops for Improving Soil Quality" EW98-012 (1998-2002).