What Is Ryegrass? Pros, Cons and How to Grow

What is ryegrass? It’s a type of fast-growing grass that withstands heavy foot traffic and does well in cold, wet conditions. Available as seed, sod, or plug, perennial ryegrass is popular as a winter grass in warmer climates and as a year-round grass in colder climes. Annual ryegrass, which is sold in the same forms as perennial ryegrass, is typically used as a cover crop, temporary turf, or for erosion control.

What Is Ryegrass?

Ryegrass is available as an annual or perennial. It stays green year-round in the right conditions and is a natural pre-emergent, releasing chemicals that inhibit the growth of weeds and other plants in the soil. That’s part of the reason why annual ryegrass is a popular cover crop, particularly in colder climates.

Perennial vs. Annual Ryegrass

Perennial ryegrass grows back year after year, while annual ryegrass dies after a single season. However, if left to go to seed, annual ryegrass will reseed itself naturally, and those seeds will germinate and grow the following spring. 

Perennial ryegrass tends to grow denser and has a darker green coloring. Perennial versions of the plant are generally more disease- and pest-resistant than their annual counterparts. If you’re having trouble figuring out what type of ryegrass you currently have, a lawn care company near you will be able to help.

Is Ryegrass Good for Lawns?

Hardy yet attractive, perennial ryegrass is great for lawns—or even grass tennis courts (it’s what Wimbledon uses). Perennial ryegrass performs best in zones 5 to 7. Because it can tolerate cooler weather, homeowners and pros alike use it to overseed hot-season lawns in zones 8 to 10. 

In these zones, where Bermuda grass is the most common, lawns go brown in the winter as Bermuda goes dormant. Therefore, many homeowners choose to overseed their lawns with ryegrass, so it’s green year-round. Both perennial and annual cultivars are suitable.

Pros and Cons of Ryegrass

Ryegrass has many benefits and uses in a variety of climates. Still, certain features of the plant make it less desirable for some gardeners. Here’s a look at some of the pros and cons of ryegrass:

Types of Ryegrass

Ryegrass is an all-encompassing term for 10 different species within the genus Lolium, but there are a few types that are commonly used as turf grass, pasture grass, and agricultural cover crops.

Perennial Ryegrass

Perennial ryegrass (Lolium perenne) is a rough-and-tumble cool-season grass. It can tolerate a lot of foot traffic and germinates quickly, though it’s not as cold-hardy as Kentucky bluegrass or tall fescue. This bunch-type grass thrives in moderate summers and cool winters. 

Perennial ryegrass is mostly used as turf grass or grazing grass for livestock. At home, you’ll find it mixed with Kentucky bluegrass to create a stronger, disease-resistant turf or used to overseed Bermuda grass lawns, which go dormant in winter.

Annual Ryegrass

You might know annual ryegrass (Lolium multiflorum) as Italian ryegrass—but it’s not actually a true annual. In some climates, it may act as a biennial or short-lived perennial. It can’t withstand cold winters, even though it’s often confused with the similarly named winter ryegrass, which is a cold-hardy ornamental grass, not a turfgrass.  

Overall, annual ryegrass is an excellent cover crop and/or effective erosion control. Depending on the climate, you can also use it as an annual forage crop because of its high yield, but it is considered invasive in some areas. 

Hybrid Ryegrass

Hybrid ryegrass (Lolium hybridum) is a cross between perennial and Italian ryegrass, so it has some of the best qualities of both. You can get hybrids that are more perennial or Italian dominant, though some of the most popular types are persistent (like perennial ryegrass) and produce a high yield (like annual ryegrass). 

These plants also tend to have more tillers (shoots) and larger leaves, which make them ideal for pastures and ground cover.

When to Plant Ryegrass

Knowing when and where to plant your ryegrass, whether it be annual or perennial, can help ensure healthy plants. Here’s when you should plant ryegrass:

• In fall or spring for the best germination rate: During these seasons, there's enough moisture in the soil and air for the grass to quickly take root and establish itself. 

• Colder seasons for perennials: Perennial ryegrass is a cool-season grass, meaning it goes dormant during the summer heat. Therefore, you need to plant it far enough ahead of the dormant period to allow the grass to mature. 

• Fall for annuals: Annual ryegrass is also a cool-season grass, but it dies off in warm summer temperatures above 90 degrees Fahrenheit. For best results, plant this type of grass in early fall.

How to Grow Ryegrass

Whether you choose to grow ryegrass from seed or install sod, growing it is fairly easy. It just takes a little preparation and care. If you need help growing or maintaining ryegrass, contact a local landscaper to assist you. 

From Seed

If you’re choosing to plant from seed, the process is fairly easy, but the initial maintenance requires a bit more work. Here are the steps gardeners should take when planting ryegrass from seed:

1. Clear the area you plan to plant.

2. Till the soil to loosen it, promote oxygenation and airflow, and allow germination and root growth.

3. Fill the area with topsoil so you have a loose layer of 4–6 inches, including the depth to which you tilled.

4. Divide seed in half. Spread 1/2 in one direction and the other half perpendicular to the direction of the first to ensure even coverage.

5. Lightly rake the seed into the soil for better germination.

6. Add a nitrogen-rich fertilizer.

7. Water daily.

From Sod

Planing ryegrass from sod is equally as easy as planting from seed, but the process looks different since you’re working with rolls of sod rather than seeds. Here are the steps:

1. Clear the area of debris, weeds, and dead grass.

2. Till over the soil to loosen it.

3. Add topsoil so you've got a loose layer with good airflow up to 6 inches.

4. Dampen the soil.

5. Lay the sod rolls in a staggered pattern as close together as possible.

6. Fill gaps between sod strips with topsoil.

7. Use a garden roller to water your sod and smooth it out simultaneously.

8. Add a nitrogen-rich fertilizer.

9. Water frequently until established.

How to Care for Your Ryegrass

Photo: jamievanbuskirk / E+ / Getty Images

Ryegrass thrives in certain conditions. It generally needs a lot of light, a decent amount of fertilizer, and a well-draining soil. This isn’t really a low-maintenance grass, but it is hardy enough to tolerate conditions that are less than ideal. Here’s how to care for your ryegrass.

Light

Ryegrass thrives in constant, direct sunlight—as long as the temperatures aren’t too hot, which could cause your grass to turn brown. 

That being said, both annual and perennial ryegrass can tolerate some shade as long as they get at least four to five hours of partial sun, though they will struggle in dappled sun. Perennial ryegrass tends to be slightly more shade tolerant than annual ryegrass.

Soil

Ryegrass prefers fertile, well-drained soil that’s slightly acidic, though it can tolerate all different soil types, including rocky or poorly-draining clay soil. Ideally, choose a well-draining loam or sandy loam with acidity between 0.6 and 0.7 pH (you can test the soil pH ahead of time and make amendments as needed). 

Keep in mind that this isn’t a hard figure. Some ryegrasses can tolerate a pH as low as 5.0.

Fertilize

When you first plant it, fertilize your grass with a lawn-starter fertilizer formulated for aiding germination, root growth, and rapid maturation with a high concentration of phosphorus. 

Six to eight weeks after germination, apply a second feed, but this time, choose a balanced fertilizer for established lawns. 

You can also choose an organic slow-release fertilizer, which is beneficial for your lawn and soil health long-term. This is because they provide nutrients over a longer period, which reduces the frequency with which you need to apply fertilizer. 

Water

When newly seeded or for new turf, water lightly daily. Once the grass reaches mowing height, reduce watering frequency to twice per week. Then, after a couple of weeks, reduce the frequency to once per week, but make sure you water deeply. 

Watering your lawn once a week or once every two weeks to a depth of at least 1 inch encourages strong, deep root growth. This builds drought tolerance, reduces competition in the topmost layer for nutrients and moisture, and creates healthier, lower-maintenance grass.

Mowing

As with most cool-season grasses, only mow when ryegrass is actively growing so that it can heal itself from the cuts of the mower blades. Never mow more than 1/3 of its height in one go, or you'll shock the plants and potentially kill large patches of your lawn. 

As a rule, the ideal mow height is:

•  1 1/2–2 1/2 inches for perennial ryegrass

• 1 1/2–2 inches for annual ryegrass

In the height of summer, when perennial ryegrass goes dormant, leave the grass at around 3 inches (the correct height to cut grass of this type) so it remains thick, lush, and healthy, even while not actively growing.

Ryegrass Yearly Care Schedule

How you care for ryegrass depends on the climate, and a local lawn care service will know best. Generally, fall and spring are the best times to seed.

If you live in a warm climate like the southern or western United States, you’ll be able to treat perennial ryegrass as a winter annual and use it to overseed your lawn so it stays green. Annual ryegrass is less common, but has similar care. 

In colder climates like the northern United States, perennial ryegrass goes dormant in the summer. If you let annual ryegrass overwinter in a cool climate, it may act like a biennial plant and sprout again in early spring. Here’s how to care for your ryegrass lawn year-round.

Spring

Ryegrass germinates at temperatures between 50 and 60 degrees Fahrenheit. If you live in a colder climate and haven’t already seeded the previous fall or have bare patches, you can seed/overseed your lawn in spring. Annual ryegrass will reseed itself in zones above 5. 

Fertilize in early spring before applying new seeds and again in late spring. Once the lawn is established, make sure your ryegrass gets at least 1 inch of water per week. 

Summer

Ryegrass in summer can struggle with extreme heat. During this period, perennial ryegrass goes dormant and annual ryegrass dies off, depending on the climate. This type of grass is not very drought-resistant, which can cause issues. To combat high summer temperatures, keep ryegrass at a height of around 3 inches during the warmest months and increase your watering amount to 1 1/4 inches.

Fall

Fall is the best time to seed with ryegrass. In warm climates, overseed your lawn when nighttime temperatures drop to 65 to 75 degrees Fahrenheit. In colder climates, seed 45 days before the first frost. 

If you already have an established perennial lawn, decrease your mowing height to 1 1/2 to 2 1/2 inches. Reduce watering to 1 inch every 10 to 14 days (in cold climates) or every week (in warm climates). 

Winter 

If you’re living in a warm climate, you can keep mowing and watering your ryegrass regularly. If you live in a colder climate, ryegrass won’t grow during the winter, so you won’t need to touch it until early spring.

Mariel Loveland contributed to this piece.