Perennial ryegrass vs annual ryegrass is a comparison often made when you’re looking to create a grass seed blend or to seed a temporary lawn. Maybe you just want to make sure you know the difference. Whatever the case may be, below you can find a thorough comparison of perennial rye vs annual rye from texture to care to cost.
Comparing Perennial Ryegrass vs. Annual Ryegrass
The primary difference between perennial ryegrass and annual ryegrass? Texture. Where perennial ryegrass is soft and a little delicate, annual ryegrass holds its own (until temperatures get too cold.) Beyond this, however, there are many large and subtle differences between these two types of grass.
Appearance of Perennial Ryegrass and Annual Ryegrass
With a fine texture and bright green appearance, perennial ryegrass is one of the more “cheery” looking turfgrass options. It holds up well under stress and stays green even while dormant for several weeks. It is a clumping-type grass and will reproduce quickly via stolons spread out under the surface.
Annual ryegrass is also bright green. However, it may start with a fine texture but after a year of mowing and periods of dormancy, it will start to show wear. This wear manifests as increased gloss and stiffness. After 2 years, annual ryegrass resembles grass-like twigs more than the lush texture most people expect a lawn to have.
Best Uses for Perennial Ryegrass and Annual Ryegrass
Perennial ryegrass is great for lawns in colder climates and transition zones. It does well with lower traffic so a yard without large pets or with set walkways is ideal. Perennial ryegrass is relatively easy to care for, is a light feeder, and can easily be removed or replaced if damaged or if it needs to be removed during a landscaping project. This grass type is also less likely to invade flower beds and other landscaping around your yard than many other more aggressive grass types.
Annual ryegrass is meant for temporary installations. It is not recommended for use anywhere a lawn will be needed for more than 2 years. Due to its texture issue and the fact that, even when used to overseed another lawn variety it can crowd out the desired variety, annual ryegrass has few places where it fits in. Perhaps the best use for annual ryegrass is if you want a temporary, fast-growing, single-season lawn and you live in a zone where the annual ryegrass will be completely killed during the winter. This allows it to be a sort of “cover” if you need some more time to choose the turf you want permanently but have already prepped the area.
Soil Types and pH Needs of Perennial Ryegrass vs. Needs of Annual Ryegrass
If you have dry, well-drained soil or live in a climate with infrequent rainfall but low temperatures, perennial ryegrass could be right at home. Due to its shallow root system, perennial ryegrass can find wet, clay-based, or even rich and loamy soils difficult to hold onto. Further, due to it primarily spreading via stolons and its shallow root system, perennial ryegrass can have a hard time living in hard and compacted soils. This can make dry, sandy soil even more ideal. Perennial ryegrass prefers soil with a pH range of 5.5 to 7.5, one of the most permissive ranges you will find for any grass type.
Annual ryegrass likes well-drained, moist soil and does dig in more than perennial ryegrass. It rarely produces stolons and will reproduce via seed if allowed to do so. Annual ryegrass finds a pH of 6 to 7 ideal.
Water Needs for Perennial Ryegrass vs. Water Needs of Annual Ryegrass
Both perennial ryegrass and annual ryegrass have similar water needs. Perennial ryegrass should receive about 1” of water each week, while annual ryegrass likes 1” to 1 ½” per week. Rain or direct watering can be used to reach this number. Further, in hot weather or any time that it will be impossible to supply this amount of water, the grass should not be cut. Allowing the grass to grow up an additional inch or inch and a half can help it conserve water and shade the ground, reducing evaporation.
Sun, Shade, and Temperature Requirements for Annual Ryegrass vs. Perennial Ryegrass
This is one of the most important distinctions between annual ryegrass and perennial ryegrass, other than texture and durability. First, perennial ryegrass should have access to full sun but will tolerate intermittent shade in small areas.
If in intermittent shade, water consumption will be somewhat reduced and less water should be given to avoid too much moisture building up in the soil. The ideal temperature range for perennial ryegrass is between 55F and 85F. Above and below these temperatures perennial rye will go dormant and, below freezing, will take some damage but may survive short, mild, freezing winters.
Annual ryegrass needs full sun. If shade is allowed to cover annual ryegrass, it may thin and die. Annual ryegrass will not tolerate temperatures below freezing for more than a handful of days. The ideal growing range for annual ryegrass is 50F to 90F. Outside of these temperatures, the grass will go into a dormant state. 20 degrees above or below these temperatures can cause severe damage and is the biggest determining factor in terms of when annual ryegrass dies.
Durability of Perennial Ryegrass and Annual Ryegrass Lawns
Neither type of ryegrass is particularly durable, both having shorter roots than many other grass types. However, perennial ryegrass holds up well to weekly mowing and general foot traffic, provided the soil is dry and well-drained. Allowing the perennial rye to grow up to 3” can increase the length of its roots enough to improve durability, especially in sloped lawns.
Annual ryegrass does not take well to being mown regularly or any type of traffic. In as little as one year of regular mowing, the texture of an annual ryegrass lawn can go from acceptable at the beginning of the season to sparse and twig-like by the end.
Common Pests and Diseases for Perennial Ryegrass and Annual Ryegrass
The average pests for perennial ryegrass and annual ryegrass are the same when speaking broadly. For example, while perennial ryegrass is susceptible to damage by digging due to its shallow roots and stolons, annual ryegrass can attract geese and moles which rip it up. Thrips, webworms, and grubs are also equally as likely to damage both types of grass. Disease is where things differ.
Perennial ryegrass is more susceptible to mold and conditions caused by excessive moisture. Annual ryegrass is likely to succumb to toadstools, fairy rings, and crown rust even when there doesn’t appear to be much damp or standing water.
Mowing Needs for Perennial Ryegrass vs Annual Ryegrass Lawns
Perennial ryegrass has average mowing needs. In most of its growing season, it will be kept at 2 to 3” with a 3” or more height being heartily recommended for any season in which temperatures stay above 80F for more than a week. Perennial ryegrass should not be mown while it is dormant to prevent damage.
The mowing needs of annual ryegrass deserve their own article. In short, however, annual ryegrass should be cut to 3” in hot weather, should never be cut while it is dormant, and it can be allowed to grow to 4” during drought conditions to preserve its life and appearance.
The major downside of annual ryegrass is that the more often it is mown, the quicker it will turn into rough, stick-like plant life that only vaguely resembles a lawn. To combat this, any permanent installation of annual ryegrass should be cut back harshly (scalped) just as it comes out of dormancy during the spring every 3 years. The lawn should then be sown heavily with new annual ryegrass seed.
Are There Better Strains of Annual Ryegrass or Perennial Ryegrass?
There are few, if any, real differences between current widely available strains of ryegrass seed. This goes for both annual and perennial ryegrass. Several brands do claim otherwise but as of the time this article was written, no evidence was supplied to support these claims.
Cost of Perennial Ryegrass vs. Annual Ryegrass
Both annual ryegrass and perennial ryegrass should cost about $3 per pound of seed, less if you have a local seed and feed supply store or grain mill that offers bulk sales of these seeds as a cover crop. Some blends and value-added fertilizer and seed combos or treated seed may cost more, depending on the contents of the package.
Can You Mix Perennial Ryegrass and Annual Ryegrass?
No, you should not mix perennial and annual ryegrass. Ideally, annual ryegrass will not be mixed with anything due to its tendency to overpower the other grass shortly after germination.
The Best-Case Scenario for a Perennial Ryegrass or Annual Ryegrass Lawn
The best-case scenario for an annual ryegrass lawn would be in a cold climate. The lawn should be seeded as early as possible in the spring, grow until fall, and then die with the frost. The lawn should then be seeded over with the permanent lawn seeds which will stay dormant through the winter and then come up the following spring with no competition.
The best-case scenario for a perennial ryegrass lawn would be as part of a mix with, for example, Kentucky bluegrass in a high-traffic area as the other grass will keep it stable. On its own, perennial ryegrass is great for low to no traffic areas and as a ground cover around and between landscaping features.
Here’s an overview of how Annual Ryegrass and Perennial Ryegrass match up across:
| Grass Type | Perennial Ryegrass | Annual Ryegrass |
|---|---|---|
| Appearance | Bright Green with Smooth, Fine Blades | Low-Quality, Stick-like Texture Glossy and Bright Green |
| Popular Uses | Winter Overseeding in Warm Climates or Low-Water Lawns and Pasture | Temporary Cover for Other Grass Types or for Winter Color in Low Use Areas |
| Ideal Soil Type and pH | Dry and Well-Drained Soil is Ideal - 5.5 to 7.5 Ideal pH | Well-Drained Sandy to Loam Soil is Ideal – 6 to 7 Ideal pH |
| Water Requirements | 1” of Water Per Week – Average Overall Water Consumption | 1” to 1 1/2” of Water Per Week – Average Overall Water Consumption |
| Sun/Shade/Temperature Needs | Full Sun Preferred/Dormant at 55F | Full Sun Preferred, Dormant Below 50F and Above 90F |
| Durability | Low-Average Durability and Damage Recovery | High Durability If You're Willing to Sacrifice Texture – This Grass Gets Firmer and More Twig-Like When Exposed to Wear |
| Pests and Diseases | Mold, Mildew, Moss, and Algae if Too Moist – Webworms, Thrips, Grubs – Digging Animals | Geese and Moles – Crown Rust, Slime Molds, Mushrooms - Webworms, Thrips, Grubs |
| Mowing Needs | Should Be Mown to 2” Height – Grows Best in Cool Weather | Should be Mown to 3” in Most Conditions, Cut Back Harshly and Reseed Every 3 Years – Mow Once a Week in Ideal Growing Season |
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