Perennial Ryegrass

Some Facts About Perennial Ryegrass

Perennial Ryegrass is a cool season grass that does well in areas that retain moderate temperatures year round. This type of grass is also more successful with full sun. However, it can adapt to partial shade.

Due to Perennial Ryegrass’s wear tolerance, you can find this type of grass in places that get high foot traffic like:

• Parks
• Schools
• Homes

Truth be told, it is difficult nowadays to find a grass mixture that does not include Perennial Ryegrass.

In fact, this grass is often mixed with Kentucky Bluegrass to help improve the disease and wear-tolerance of the lawn.

Its success with sod production, athletic fields, and golf courses (but not the greens) have made it highly desirable. Mixing it with other types of grasses is a common practice to help to improve those other grass choices.

Characteristices & Traits

Perennial Ryegrass germinates quickly and is helpful for over-seeding Bermuda Grass, which is dormant during the winter.But what about the look? This rich green grass is a popular one for homes.

There are outgrowths (or auricles) that grasp the stem on the collar. There are also no stolons or rhizomes. This type of grass forms clumps when marginally adapted and retains a bunchgrass-type growth formation.

The leaf margins are parallel. It is finely textured, and the leaf is folded in the bud. The backside of the leaf is shiny with tapered tips.

To get a quick idea of this grass’s tolerances, consider this:

Moderate to high tolerance for:

• Full sun
• Wear
• Disease

Yet has a low tolerance for:

• Anything more than partial shade
• Heat
• Drought

Where Did It Come From & What Are The Varieties?

In the early 1960s, the first type of perennial turf grasses were released in the U.S. Since then, it has gained most of its popularity in the western parts of Washington and Oregon as well as lower regions of western British Columbia in Canada.

It can also be found in great abundance in the interior sections of the Pacific Northwest. It does not matter if the project is a golf course, athletic field, or a home lawn; this grass is an excellent choice. So where did it come from prior to the turf grass of the 1960s?

This type of grass was actually used for over 300 years as animal forage. However, it was not until the early ’60s that it made the crossover to popular turf grass. However, it originally had poor tolerance to heat and cold, was lousy quality for mowing, and needed high nitrogen fertilizer levels to succeed. Most of its major improvements came in the ’80s and have helped this grass become even more popular over the years.

In fact, the changes made during the ’80s had other great results—it improved the resistance to pests like chinch bugs, bill bugs, and sod webworm. There are actually two types of Ryegrass: Perennial and Annual. However, this will focus on Perennial Ryegrass. Some of the variations depend on whether you are using the grass for lawn, pasture, or another project, such as a sports field or park.

For pasture use, this grass is a good choice because it is highly digestible and favored by animals like deer, horse, and cattle. Some of the variety choices include:

• Linn Perennial Ryegrass
• Citadel
• Achiever
• Pagent
• Madera
• Windstar
• Mongita
• Festulolium

These various strains have been created to offer solutions to what consumers
specifically want:

• Better color
• Better resistance to drought issues
• Less susceptibility to diseases
• Improved leaf structure
• Better tolerance to the cold

Advantages & Disadvantages

Regardless of which grass you pick, there are bound to be some pros and cons. The idea is to pick the grass with the best advantages for your circumstances, not to mention a choice with as few disadvantages that would impact you.

Perennial Ryegrass can actually be a little more tolerant than most other types of grasses, but of course it has its setbacks. Here are some quick advantages and disadvantages:

Advantages

• Probably the best wear-tolerance for cool season grass choices.
• Germinates quickly and a great choice for over-seeding winter dormant grass like Bermuda Grass.
• This grass can help add wear- and disease-tolerance to a lawn when mixed with another type of grass that is lacking in those areas.
• Produces lower levels of thatch, which is a common issue with cool-season grasses, than its counterparts.

Disadvantages

• Requires moderate to high maintenance.
• Low tolerance for heat and prefers moderate year round temperatures.
• Low tolerance for shade and drought.
• Use as over-seeding for warm season grasses can result in it becoming “weedy” after a few years.
• If used alone, after a few years it can become “stemy.”

Establishment & Maintenance

You have the choice of seed or sod when it comes to planting. If you are going to use seed, fall is the best time to plant. The good news is that these seeds germinate quickly, usually within three to five days if moderate temperatures are present.

It takes one to two months for a rapid turf to take hold. From there, proper care will help ensure success. Fertilize during times of active growth, such as February to June and October to December using four pounds of nitrogen for every 1,000 square feet.

Watering, Mowing & Pest Management

Perennial Ryegrass requires frequent watering and should be watered to a depth of 6–12 inches. If using to over-seed any warm-season grasses, take a slightly different approach. If you water more deeply but less often, it helps to encourage those warm-season grasses that are emerging from dormancy. Keep in mind that Perennial Ryegrass is drought sensitive, so proper irrigation is mandatory for success.

Mowing this type of grass is thought to be slightly more difficult than other types. Ideal mowing height varies depending on whether the grass is pure or mixed. For pure Perennial Ryegrass, you should keep the grass at a height of 1.5–2.5 inches. However, if you are using the grass for over-seeding with warm-season grasses, it is a good idea to gradually reduce the grass height during spring by mowing it more closely and more often. This will promote warm-season grasses while they emerge from their winter dormant state.

Another thing to be aware of is that when planted alone, this type of grass can end up becoming “stemy” and when it is used for over-seeding, it can become “weedy” after a few years. When used for over-seeding, though, the Perennial Ryegrass may suppress the germination of the other seedlings, which basically means it takes over.

A change to the Perennial Ryegrass during the ’80s helped increase its resistance to certain pests. However, now this type of grass has issues with things like grey leafspot disease.

This is more common in areas with heightened summer stresses like humidity and heat. This type of grass is also susceptible to these fungal diseases:

• Dollar Spot
• Red Thread
• Rust
• Slime Mold
• Brown Patch

And these insects:

• White grubs
• Japanese Beetle
• Ants
• Thrips

The end result with Perennial Ryegrass is an attractive and lush lawn. However, be sure to consider the time required to care for this type of grass. And keep in mind that if pure Perennial Ryegrass does not seem right for you, a mixture with it could still be a good option.