Perennial Ryegrass vs Annual Ryegrass – Comparisons + Which to Choose for Your Winter Lawn

Perennial and annual ryegrass are all great for overseeding a warm-season grass like Bermuda for a lush green lawn during winter. The main difference between these two grasses is their lifecycle. 

Annual ryegrass has a short lifecycle, lasting within a year (8-10 months).  Perennial ryegrass, on the other hand, is long-lived, lasting 4-5 years.

Beyond their lifespan, these two types of ryegrass have different care needs and functionalities. To understand which is better for your lawn, let’s dive into their comparisons. 

Perennial Ryegrass vs Annual Ryegrass – Comparisons

Perennial and annual ryegrass have different needs for water, temperature, soil, and mowing. Their appearance and costs are also dissimilar. 

Watering  Needs

Both perennial and annual ryegrass have slight differences in their watering needs. Perennial ryegrass requires at least 1 inch of water per week, while annual ryegrass may require 1 to 1 ½ inches of water within the same period.

Temperature Requirements

Perennial ryegrass thrives within a temperature range of 55°F  (12.8 °C) to 85 °F  (29.4 °C). Temperatures above this range will cause it to enter dormancy. This grass only survives short and mild winters.

Annual ryegrass, on the other hand, can thrive in a temperature range of 50 °F (10 °C) to 90 °F (32.2 °C). Extreme temperatures above or below this range can severely damage annual ryegrass. 

USDA Zone 

Perennial ryegrass is ideal for cool climates and transitional zones. It thrives in USDA zones 5 – 7. It’s ideal for permanent, high-traffic lawns and pastures. While annual ryegrass is ideal in zones 4 to 9. However, it can handle temperatures down to 40°F in zone 3a.

Appearance

Perennial ryegrass has a fine texture with a dark green appearance, while annual ryegrass has a coarse texture with a bright green appearance. Annual ryegrass will resemble grass-like twigs at the end of the cycle rather than a lush texture. 

Soil Requirement

Perennial ryegrass thrives in well-drained sandy soil with a pH range of 5.5 to 7.5. Due to its shallow roots, it needs consistent moisture and fertile soil for optimum growth. Annual ryegrass prefers silty soil with good drainage and a pH of 6 to 7.

Seed cost

Perennial ryegrass seed is more expensive, but you take years before buying again. Annual ryegrass seed is less expensive, but you will have to keep buying it every year when you want to reseed your warm-season grass. This eventually makes it expensive in the long run.

Mowing need

Annual ryegrass has rapid growth, thus it needs regular mowing. Perennial ryegrass, on the other hand, germinates quickly but establishes slowly. However, both should be mowed to a height of 2 to 3 inches for a standard lawn appearance and good health of the grass.

Pros and Cons of Perennial Ryegrass

Perennial ryegrass offers great versatility. However, like any other type of grass, it has its own pros and cons.

Perennial Ryegrass pros

• Great wear tolerance: Perennial ryegrass has the highest wear tolerance among the cool-season grasses. This makes it a great choice for parks, fields, and high-use lawns.
• Pests and disease tolerance: Perennial ryegrass has a moderate tolerance to diseases like mold, mildew, moss, and algae in moist areas as compared to other types of grasses. Furthermore, it’s also tolerant to pests like webworms and thrips.
• Establishes rapidly: Unlike other types of grass, perennial ryegrass germinates and establishes within a short period of time.  It’s a high-yielding grass with a long growing season.
• Excellent forage crop: Perennial ryegrass can be planted as a fodder crop for animals. When harvested, it can be stored as hay to be fed to domestic animals.

Perennial Ryegrass Cons

• Difficult to eradicate: Perennial ryegrass spreads fast through stolons and rhizomes that are difficult to control. It is hard to control it when spread to garden beds, pathways, and driveways.
• Hard to maintain: Perennial ryegrass requires extensive care as compared to other types of grass. It requires regular fertilizing, watering, and mowing. It can easily get out of control when not mowed regularly.

Pros and Cons of Annual Ryegrass

Annual Ryegrass Pros

• Control soil erosion: Annual ryegrass germinates and grows rapidly to cover the ground. It offers a natural solution to water runoff and wind erosion.
• Chokes out weeds easily: With a fast growth rate, annual ryegrass can smother out the weeds. It can also be used as a natural pre-emergent due to its allelopathic properties.
• Germinates Fast: Annual ryegrass has a fast germination rate of 5 to 10 days. 
• Tolerance to foot traffic: It has a coarse texture that is ideal for high foot traffic areas in your lawn, such as children and pet playing areas. It also has a high wear tolerance as compared to other grass species.

Annual Ryegrass Cons

• Require regular re-seeding: Annual ryegrass has a short lifecycle. You have to keep on re-seeding your lawn every year at the end of the season. 
• Turf degrades over time: Annual ryegrass is likely to degrade towards the end of the season to resemble grass-like twigs instead of a lush green lawn. 

Which is Better between Perennial and Annual Ryegrass

A choice between perennial and annual ryegrass depends on your needs. Each of the two species has its own advantages and disadvantages. Both are cool-season grasses that can provide a green lawn in winter. For long-term goals, go for Perennial ryegrass. However, both types have almost similar maintenance routines. 

Final Thoughts

The biggest difference between perennial and annual ryegrass is their lifecycle. Perennial ryegrass offers a continuous growth cycle year after year, while annual ryegrass will require re-seeding at the end of every season. Choosing the best between the two will depend on your preference.