Perennial Ryegrass has found its way into lawns all over the United States. It has a fine texture, bright green color, and remarkable durability, which makes it popular in school yards and lawns that need resilience to children and pets. Perennial Rye also germinates incredibly quickly, making it great for people wanting their lawn to green promptly or stay green throughout the winter. Scroll down to learn everything you need to know about Perennial Ryegrass for lawns.
Often, ryegrass is used in grass mixes, but not for seeding an entire lawn.
It’s a sod-forming grass that pairs well with Kentucky Bluegrass and Fescue grass. Of the cool season grasses, perennial ryegrass has the best wear tolerance and the fastest germination rate.
This makes it a great choice for high traffic areas, and it’s also selected for many seed blends you’ll find sold in box stores and hardware stores across the country. It gives fast, visible results and a feeling of success to homeowners who are planting grass seed, but it’s a bit high maintenance in the long run.
We’ll get into that, but first let’s take a look at where you should grow a ryegrass lawn.
Regions and Climates for Perennial Ryegrass
As a cool-season grass, ryegrass grows best in the northern regions of the United States. It thrives particularly well in the northern coastal regions.
It’s found most prevalently in the Pacific Northwest, in states like Oregon or Washington.
Ryegrass isn’t particularly good in the transition zone, where it will often succumb to heat and drought and go dormant without proper irrigation and fertilization.
However, homeowners in the southern states may use perennial ryegrass as a winter grass to green up their lawn during the cooler months when their warm season lawn goes dormant.
Ryegrass is often overseeded into Bermudagrass as the weather cools. When the temperature rises in the spring, it either dies off or goes dormant and the bermuda lawn takes over again.
Ryegrass has good cold tolerance and can withstand some shade, though it prefers sun.
A Short History of Ryegrass
Ryegrass is native to Europe, Asia, and northern Africa. It made its way to the United States as a turfgrass for the first time in the 1960s.
Prior to that, it had been used as animal forage for hundreds of years. The early turfgrass varieties of ryegrass had tough textures and were difficult to work with.
However, its quick germination made it popular as a winter grass in the south. Later cultivations created ryegrass that was more amenable, and it became more popular for turf.
The newest cultivars have increased pest resistance due to the presence of endophytes, though it still has issues with leaf spot disease.
Perennial ryegrass is not related to the rye wheat variety used to make bread, cereal, or whiskey. Rye can be eaten whole, either as berries or rolled, like oats.
Ryegrass has agricultural uses outside of turfgrass, such as pasture feeding and making hay for livestock.
Growing Perennial Ryegrass in your Yard
Perennial ryegrass germinates quickly but spreads slowly. It spreads using vertical shoots called tillers; it does not spread using rhizomes or stolons.
Similar to tall fescue, ryegrass grows in clumps. Traditional varieties have very shallow roots and generally do not have tolerances for heat or drought.
Newer cultivars have been bred to have deeper root systems and increased drought tolerance, but it is not consistent across ryegrass varieties.
Its quick germination and slow spread makes it popular for seed mixes. Fescues and Kentucky bluegrass can take up to 21 days to germinate, whereas ryegrass can germinate in as few as four days in ideal conditions.
That will make newly seeded lawns green very quickly, and it has the added benefit of protecting the seedling grasses throughout their longer germination.
Ryegrass requires more water and fertilizer than fescues and goes dormant during warm seasons. It prefers lawns with a pH of 5.5 to 7.5.
A drawback of ryegrass is the narrower than average temperature range in which it thrives. It goes dormant when too warm but also cannot withstand the extreme cold of winters in northern areas, like Maine.
Ryegrass performs differently when mixed with other grasses. It will typically grow faster than the other grasses in the mix.
Watering and mowing requirements will be best explained in the seed’s packaging instructions. Depending on its mix of other seeds, like Kentucky bluegrass or fescues, its water level will be affected.
Regions to Grow Ryegrass
Perennial ryegrass is a cool season grass; however, it grows best in northern coastal regions where the temperatures remain comparatively consistent throughout the year.
The most common place to find perennial ryegrass in the United States is in the Pacific Northwest. It is also found in northern regions, like New England and the Carolinas.
As I touched on earlier, perennial ryegrass cannot withstand the extreme cold of the far north, and it does not grow in the warmer southern areas.
Ryegrass is also used prevalently in southern states to maintain green lawns throughout the year.
Either perennial ryegrass or annual ryegrass is added to warm season grasses, like Bermudagrass, in October when the other grasses are going dormant.
It establishes itself quickly and then dies out when the weather becomes too warm in the springtime.
Common Issues with Ryegrass
Ryegrass is not without its issues. This largely contributes to why it is regularly added to lawns and is rarely used on its own.
The largest issue is how slowly it spreads.
Ryegrass spreads through tillers, and not with either rhizomes or stolons like some Turf Type Tall Fescues and Kentucky Bluegrass. As a result, it forms clumps that do not spread and is prone to patchy looking lawns.
To combat this, you’ll need to frequently re-seed since it does not fill in on its own.
One of the main reasons why ryegrass isn’t planted just by itself is that it can grow in thick stems that are unsightly and difficult to mow unless you’re an absolute fanatic about mowing.
Its slow spreading nature will also form into bunches that are unsightly and difficult to work with. Ryegrass also has historically been very rough on mowers.
It grows in bunches and tends to wear out the blades so you’ll need to sharpen your mower blades or replace them more frequently.
This leads to tearing the grass when mowing instead of cutting it cleanly, which makes it even more susceptible to diseases.
Pests and Disease in Ryegrass Lawns
Although recent cultivars have been developed to be more resilient, ryegrasses have shown susceptibility to certain illnesses and pests.
Ryegrass is at risk for dollar spot, red thread, rusts, and brown patch. It also has susceptibility to lawn grubs.
These are generally worse when it’s warmer or more humid. Proper maintenance, tailored to your environment, can prevent many diseases.
For persistent issues, you can apply fungicides and/or insecticides. Make sure to read and follow the product instructions, and to be mindful any time you use these products with pets or children.
Kids and pets spend so much time in the grass, you really have to weigh that in your decision about what to apply to your lawn.
Perennial vs Annual Ryegrass
There are over a dozen types of ryegrass globally, but only two found regularly in the United States. Aside from perennial ryegrass, there is an annual ryegrass that will die out within a year.
Annual ryegrass is the variety used most commonly for overseeding warm-season lawns. The seeds are generally inexpensive, and the grass grows like gangbusters.
It doesn’t have a strong market amongst professional turf growers because it doesn’t create quality or sustainable turf. Another common use for annual ryegrass is to hold soil stability during the winter months, or for erosion control when construction projects occur.
This is common in public areas, though homeowners have been known to do this on occasion, especially in warmer climates. Since it germinates so quickly, annual ryegrass is planted to keep the soil stable if the timing wouldn’t allow a perennial grass to establish itself.
The preferred grass is then planted in springtime.
When doing this, it’s important to mow regularly to prevent the annual ryegrass from being able to seed.
If that isn’t done, the temporary ryegrass will become a weed in the new lawn.
Shopping for Ryegrass Seed
It’s important to have an awareness and understanding of what annual ryegrass is (and isn’t) for when looking for seeds to buy.
Annual ryegrass is a very inexpensive grass seed, so if you’re choosing grass seed based on cost be careful you’re not purchasing an annual variety.
TIP: Every bag of grass seed you’ll find at the local hardware store or box store has two things to look for:
- A Date – try to buy the freshest bag of seed you can (that will give you the best germination rate).
- A List of Seeds Used – look for perennial ryegrass over annual ryegrass if you are trying to plant a permanent lawn.
Additionally, if you’re purchasing a seed mix, make sure to understand the proportion mixture. Cheaper mixes will include disproportionately high amounts of ryegrass seed, but the best grass seed blends (like those sold by Jonathan Green) will be predominantly elite patented Fescues.
The Best Time to Plant Ryegrass
Perennial ryegrass is a cool season grass and grows best in the spring and the fall. Thus, it is best planted in early October for the upstate, Atlantic region, or late October for the coastal or northern, midwestern regions.
The best times usually occur about 30 to 45 days prior to the first frost, when the daytime temperatures are about 70 degrees Fahrenheit and nighttime lows don’t drop below 50 degrees Fahrenheit.
Perennial ryegrass doesn’t perform well in warmer weather and you shouldn’t plant it in the spring. It won’t have enough time to germinate before the weather getting hot enough to make the grass go dormant.
Planting Perennial Ryegrass
You can purchase sod to quickly lay your lawn, though with ryegrass’s quick germination and inexpensive seed cost, that usually isn’t necessary.
I have a number of articles about planting grass seed for a new lawn, and tips for aerating and overseeding an existing lawn to guide you.
Aerate the lawn to increase oxygen and water flow to the roots for better germination. Also, layer sand or compost to improve soil quality.
Most manufacturers suggest a seeding rate of six to nine pounds of seed per 1,000 square feet of new lawn, but I actually recommend you spread ryegrass a little heavier than that. I suggest you use 10 pounds per 1,000 square feet for new lawns, and 5 pounds per 1,000 square feet for overseeding existing lawns.
You can calculate the exact amount of seed you should spread in your lawn by using my grass seed calculator right here.
And if you need to get an accurate measurement of your yard’s square footage, I’ve got you covered there too with my free lawn size measuring tool:
These two custom apps I hired a developer to build for my readers can really help you dial in your project and order exactly what you need.
When Your Ryegrass Lawn Germinates
A good ryegrass seed will germinate within three to five days if conditions are optimal, and the turf will be mature in four to eight weeks. You can expect to mow your ryegrass for the first time about two weeks after seeding – when it’s approximately three inches tall.
Just remember – you never want to cut more than 1/3 the length of your grass at any one time – especially with young grass.
If you’re using a seed blend with Perennial Ryegrass, it’s best to follow the specific instructions found in the packaging.
Fertilizing Perennial Ryegrass
When you plant your ryegrass seed, apply a good starter fertilizer with a high nitrogen and phosphorus level in the three-number NPK ratio on the packaging.
- Nitrogen is the first number of the three and will help your new grass push leaf growth to promote photosynthesis.
- Phosphorus is the second number and will help the grass quickly take root and grow deeper roots to become more resilient faster.
I like to apply a slow-release fertilizer like Milorganite 3-4 weeks after spreading the seed and starter fertilizer. You can buy it on Amazon, but I always find the best price online at Ace Hardware, which delivers locally to me for free. This application ensures the young grass gets plenty of balanced nutrients as it matures.
Something to Note About Ryegrass
Ryegrass is also an “allelopathic” grass, which means it produces and releases a chemical that inhibits the growth of plants around it. Other plants absorb this chemical through their roots, resulting in stunted growth.
While this is beneficial for slowing the growth of weeds, like crabgrass, it’s harmful if it is planted close to something that you want to thrive, so that’s worth pointing out.
How you overseed your lawn depends on the current condition of your grass. For a lawn that is already established, overseed at a rate of five pounds of seed per 1,000 square feet.
This rate is enough to make your lawn thicker and greener without creating issues during the transition. If you’re trying to repair a horrible lawn without killing your lawn and starting over, seed at a rate closer to the 10 pounds per 1,000 feet that I recommend for new lawns.
Your lawn will grow in greener and thicker, and it will be resilient throughout the winter. Prior to overseeding, mow your existing lawn low, to about one inch.
Rake the grass scraps from your lawn and spread the seeds over your lawn. You should aerate your lawn before overseeding, as it will allow more oxygen and water to get to the grass roots.
Spread the grass over your lawn, going initially in one direction, then again in a direction perpendicular to the original one.
Use the back of a rake or a stiff broom to push the seed into the ground. You want the seeds to get more surface contact with the soil.
Water the lawn lightly several times daily while the seeds germinate. Frequent light watering will keep the ground and seeds moist without washing away the seeds before they germinate.
Clay soils retain more water since they don’t drain as much. As a result, they require less water.
Sandy soils drain water more quickly and require more watering. Once seed is distributed, add a starter fertilizer and compost to your new seed to help it take root and germinate more quickly.
When overseeding your warm season lawn for the cooler months, the amount of seed you should use depends on the type of grass you have.
For Bermudagrass lawns, color plays a bigger role than grass density. In this case it’s best to seed it at a rate of five to seven pounds per 1,000 square feet.
To do so, mow your Bermudagrass turf very low, to just about one inch high. Then, using a spreader, broadcast your seed over the surface.
Using the back of a hard rake, push the seeds into the ground to increase the amount of surface contact. Apply a starter fertilizer to help the new grass grow in strong.
It would also be beneficial to aerate your lawn prior to seeding. This allows more oxygen and water to get to the roots.
Perennial ryegrass performs best at a mowing height of 1 ½ to 2 ½ inches. But this varies depending on which other grasses it has been planted with.
For instance, when planted with Kentucky Bluegrass, it should be mowed slightly higher. I recommend a minimum height between 2 to 2 ½ inches in this case.
During the warmer season, letting your grass grow longer promotes stronger root development. In the cooler seasons, it can withstand being cut at a lower mower height adjustment.
Water ryegrass to a depth of 6 to 12 inches, and provide your lawn with at least 1″ of water weekly. Deep, infrequent watering promotes deep, healthy root systems and helps with drought resilience.
If you used Rye to overseed, your lawn would not need water as frequently. A lot of your grass is already well established.
Watering Perennial Ryegrass Lawns
It’s important to note that Ryegrass is not drought resistant. It will go dormant or die off without enough water during the warmer months.
This means if you plant Ryegrass in spring, you’ll need to stay on top of irrigation that first summer. Fail to do so and your grass will quickly go dormant or die during that first year.
When newly planted, water lightly two to three times daily to keep the seed moist, depending on the weather and your climate. Make sure not to water too heavily at once or you’ll risk washing away the new seed.
After germination cut back to twice daily the first week, then once daily the second week.
As your grass matures, slowly spread out the frequency of irrigation. Water deeply and less frequently to encourage your new lawn to develop deep, healthy roots.
How Much Fertilizer Does an Established Perennial Ryegrass Lawn Need?
Ryegrass requires regular fertilizing. It performs best when it has 4 pounds of nitrogen per 1,000 square feet during its active growth period. Choosing a fertilizer with a nitrogen rating (the first number on the bag) of about 16 is your best option. This is outside of the seeding recommendations I provided earlier.
Since it’s a cool season grass, ryegrass requires fertilizer throughout the year and not just during the warm months.
I recommend overseeding Perennial Ryegrass lawns annually to keep them thick and healthy. Fail to do so and you’ll see a patchy appearance within a few years.
Adding new ryegrass or a quality grass seed blend appropriate for your growing zone will strengthen your lawn. A thick lawn crowds out weeds and looks great.
Final Thoughts About Perennial Ryegrass Lawns
Perennial ryegrass is an increasingly popular turfgrass and commonly found in grass mixes. With an incredibly quick germination time, this grass grows and greens more quickly than most other varieties.
It is also popular for overseeding because it repairs lawns quickly and is completely easy to grow from seed.
In southern areas, homeowners use ryegrass to overseed winter lawns. This keeps their yard green during the cool season, until the warm-season grasses come back to life in the spring.
No matter where you are, for most homeowners I don’t recommend establishing a perennial ryegrass monoculture in your yard. You’ll be better off using a seed blend which contains high quality perennial ryegrass along with elite fescues and bluegrass. I recommend the Black Beauty Ultra mixture from Jonathan Green.
It’s the product I use to overseed my own lawn, and I love it.
When left to itself, Perennial Ryegrass grows in as bunches. This means it needs to be overseeded frequently to prevent a patchy appearance. However, when mixed with other grasses, ryegrass adds beautiful color and a wonderful sheen. It also adds extra strength and resilience to lawns with heavy traffic.