What is the Difference Between Annual and Perennial Ryegrass

The main difference between annual and perennial ryegrass is that annual ryegrass is a cool-season grass whereas perennial ryegrass can tolerate both cold and warm temperatures. Furthermore, Lolium multiflorum is the scientific name for annual ryegrass while Lolium perenne is the scientific name for perennial ryegrass.

Annual, perennial, and winter ryegrass are the three types of ryegrasses classified mainly based on the type of growing season.

Key Areas Covered

1. What is Annual Ryegrass
     – Definition, Features, Importance
2. What is Perennial Ryegrass
     – Definition, Features, Importance
3. What are the Similarities Between Annual and Perennial Ryegrass
     – Outline of Common Features
4. What is the Difference Between Annual and Perennial Ryegrass
     – Comparison of Key Differences

Key Terms

Annual Ryegrass, Cool Temperatures, Lawns, Perennial Ryegrass, Silage

What is Annual Ryegrass

Annual ryegrass (Lolium perenne) or Italian ryegrass is a type of cool-temperature ryegrass native to temperate Europe. It can be grown in fall and spring, but it readily becomes dormant during the warm season. Therefore, annual ryegrass is suitable for overseeding lawns to grow along with warm-temperature grasses. It helps to keep a green expanse for a longer duration.

Figure 1: Annual Ryegrass

Furthermore, annual ryegrass is more suitable to cover bare grounds as it fights against soil erosion. Also, this type of grass is very cheap. Therefore, it can be used to fill temporary turf. In addition, annual ryegrass is eco-friendly as it is non-aggressive and furnishes nutrients back to the soil. However, it can become an invasive species in agricultural areas as well.

What is Perennial Ryegrass

Perennial ryegrass (Lolium perenne) or European ryegrass is another type of ryegrass with a longer lifespan. It means that perennial ryegrass can grow up to 1-3 years. But, it has a higher growth rate during cool seasons. Due to the longer lifespan and the ability to tolerate both cold and warm temperatures, perennial ryegrass is widely used in lawns.

Figure 2: Perennial Ryegrass

However, one drawback of perennial grass is its inability to tolerate shades. It needs direct sunlight for proper growth. Moreover, it can tolerate foot traffic well. Due to these favorable characteristics, perennial ryegrass is widely grown all over the world including north of the tropical areas into the transition zone and into the regions of the cold season zone.

Similarities Between Annual and Perennial Ryegrass

• Annual and perennial ryegrass are two types of ryegrasses classified based on the growing conditions.
• Generally, ryegrasses are characterized by their bunch-like growth.
• Also, both grow well when the soil temperature is between 50 and 65 degrees F.
• But, they cannot tolerate extreme temperature conditions.
• Besides, their rate of seed germination and the rate of growth are high.
• Furthermore, both ryegrasses are used for grazing and hay and silage production.

Difference Between Annual and Perennial Ryegrass

Definition

Annual ryegrass refers to the cool-season grass that originated in southern Europe while perennial ryegrass refers to a cool-season grass, meaning it peaks in growth during cool seasons, from fall through spring. Thus, this is the main difference between annual and perennial ryegrass.

Scientific Name

Lolium multiflorum is the scientific name for annual ryegrass while Lolium perenne is the scientific name for the perennial ryegrass.

Native to

Annual ryegrass is native to Southern Europe while perennial ryegrass is native to Europe, Asia, and northern Africa. Hence, this is also a difference between annual and perennial ryegrass.

Other Names

Moreover, another name for annual ryegrass is Italian ryegrass while another name for the perennial ryegrass is English ryegrass.

Growing Season

Another difference between annual and perennial ryegrass is their growing season. Annual ryegrass can be grown in fall or in the spring while perennial ryegrass comes back year after year in permanent lawns.

Lifespan

Their lifespan is also a major difference between annual and perennial ryegrass. The lifespan of annual ryegrass is short while the lifespan of perennial ryegrass is long.

Under Warm Temperatures

Moreover, annual ryegrass is not suitable to grow in warm temperatures while perennial ryegrass is more suitable for drying out under warm temperatures.

Lawns in Single Strands

Annual ryegrass is not suitable for the lawns in single strands often cultivated with warm-temperature grasses while perennial ryegrass is suitable for lawns in single strands since they can produce foliage throughout the year. Thus, this is one other difference between annual and perennial ryegrass.

Conclusion

Annual ryegrass is a type of ryegrass with a short lifespan. It can be grown in fall and spring under cool temperatures. In comparison, perennial ryegrass is another type of ryegrass with a longer lifespan. It can tolerate warm temperatures to a certain extent and they live up to 1-3 years. Both types of ryegrass are important for grazing and for the production of silage. However, the main difference between annual and perennial ryegrass is their ability to tolerate warm temperatures.

References:

1. “Planting Areas For Annual, Perennial, Or Winter Ryegrass.” SEEDLAND, Available Here.

Image Courtesy:

1. “Westerwolds raaigras Lolium multiflorum” By Rasbak – Own work (CC BY-SA 3.0) via Commons Wikimedia  
2. “Lolium perenne Engels raaigras doorschietend” By Rasbak – Own work (CC BY-SA 3.0) via Commons Wikimedia