Perennial Ryegrass is a popular cool-season turfgrass that can add quick color and curb appeal to a new property. Ryegrass germinates and grows quickly and thrives in states with cool, moist climates where it can serve as a permanent turf. Perennial ryegrass is also appreciated in warmer southern states where it is frequently used to improve the look of a dormant lawn of Bermudagrass or other warm-season turf during the winter months through overseeding in the fall.
If you have Perennial Ryegrass in your yard, read this guide to learn more about how to care for your turf, including:
- When to mow, aerate, and de-thatch ryegrass
- How to control weeds and disease in ryegrass
- What pests to look out for around ryegrass
What is Perennial Ryegrass?
Perennial ryegrass, formally named Lolium perenne L., is a quickly growing turfgrass found across the United States. It thrives in moderate, damp climates and is less tolerant of cold than the popular Kentucky Bluegrass.
Ryegrass is dark green in color, and shiny, with smooth, fine leaves that sometimes resemble those of bluegrass. The roots of ryegrass are rather shallow, rarely growing deeper than a few inches under the ground. Ryegrass does not spread laterally with stolons or rhizomes like some turfs do, so care should be taken to seed evenly. The grass tolerates traffic well and is suitable for some golf course areas.
Other varieties of ryegrass can be used as pasture grasses for livestock, providing high nutritional value to the animals, and some types can offer important erosion control to certain soils. Despite the name, ryegrass is not related to the grain-producing rye plant.
Quackgrass is a perennial weed that can sometimes resemble perennial ryegrass and be mistaken for the desirable turf. Consult our Quackgrass Weed Guide and compare the blades of the grass you have sighted to confirm which plant is growing and how it should be treated.
How to Care for Perennial Ryegrass
Mowing a Perennial Ryegrass Lawn
Perennial Ryegrass should generally be mowed to a height of 1.5 to 2.5 inches during its usual growing seasons of the fall and winter. Start mowing your ryegrass lawn when it begins to grow in the fall. In northern states where ryegrass is used as a permanent lawn, the turf will grow more slowly or go entirely dormant in the summer. Adjust your mowing schedule as needed to match these changes.
In times of heat or drought, raising the mow height to 3 to 4 inches can reduce stress on the turf. The mowing height can be lowered again as cooler temperatures arrive in the fall. You should continue to mow your ryegrass turf until it stops growing.
If you are using ryegrass for overseeding among a warm-season turf such as Bermudagrass, lower your mowing height in the springtime and mow the overseeded area more frequently to allow the dormant warm-season turfgrass more freedom to emerge and get the sunlight it needs.
Seeding and Sodding Perennial Ryegrass
Perennial Ryegrass grows quickly from seed--it can germinate in just three to five days in a moderate climate. This quick start makes ryegrass a popular choice for overseeding lawns that need a quick green-up, or for new residential developments.
Ryegrass should be seeded in the fall, and a recommended overseeding rate is to use 5 to 6 pounds of seed per 1000 square feet of lawn area. This seeding strategy should yield a cover of turf within the first two months.
If you are seeding a barren area for erosion protection reasons, apply 10 pounds of ryegrass seed per 1000 square feet of area.
If your schedule does not allow for planting ryegrass from seed in the fall, planting from seed in the springtime could be your second best option. While soil temperatures are still warming in the spring, you will have another opportunity for a ryegrass lawn to germinate and establish itself before the warmer temperatures of summer interfere with its growth.
There is also the option to use sod at other times of the year if you are unable to seed on the recommended schedule.
Dethatching a Perennial Ryegrass Lawn
Perennial Ryegrass produces less thatch than most other popular cool-season turfs, and dethatching is rarely needed, especially in the winter months when the turf naturally thins out.
In the fall, it is best to rake up fallen leaves or thatch so that your ryegrass starts the winter free of ground cover that could rob it of sunlight.
Aerating a Perennial Ryegrass Lawn
If your soil is compacted and dense, an annual aeration can help turfgrass growth and overall lawn health. If you plan to overseed with perennial ryegrass, the best time to plant is immediately after performing an aeration of the soil for the best seeding results.
Fertilizing Perennial Ryegrass
Perennial Ryegrass lawns often need added Nitrogen during their periods of active growth--between February and June and in the fall between October and December.
Add nitrogen to your perennial ryegrass lawn at a rate of 4 pounds per 1000 square feet for most cases.
You can also use an at-home soil test kit to learn your soil's current nutrient and pH levels. With the results from a soil test, you can add other fertilizers or amendments that may be needed to improve the health of your soil and your turf. You can also take a soil sample to your local extension office for this information and additional advice regarding perennial ryegrass lawn health.
Watering Perennial Ryegrass
Perennial ryegrass does best when it is well-watered on a regular basis. Ryegrass that doesn't get enough water can go into a state of dormancy, which it can be slow to recover from. Dormant turf is also more likely to lose health to lawn disease, insect pests, and competing weeds. Maintain a regular watering schedule while ryegrass is dormant.
Make a plan that gives your perennial ryegrass lawn about 1 inch of water per week on a consistent basis. You can change the amount of water you add to adjust for local rainfall.
Perennial Ryegrass Weeds and Diseases
Perennial Ryegrass can be harmed by invasive weeds and lawn diseases like most turfs. With the right planning and pro-picked products from DoMyOwn, you can keep these natural bothers under control and help your lawn thrive.
Weed Control for Perennial Ryegrass
Some winter broadleaf weeds that are often found in perennial ryegrass lawns are henbit and chickweed. These unwanted weeds can typically be controlled in an established ryegrass lawn with applications of 2,4-D products labeled for the pest weed and your turf type. These applications should be made soon after the weeds appear in October or November, but there could be an exception to this recommendation for newly seeded or overseeded lawns. Some products will list a waiting period after seeding during which the herbicide should not be applied to avoid injuring the grass seedlings. Read the label of your selected herbicide carefully before applying.
You can prevent these weeds from germinating with a timely application of a pre-emergent herbicide in the fall and a second application in the spring. See our guide on pre-emergent herbicides for best practices and application information.
Some pre-emergents, such as those including the active ingredient mesotrione, can be applied at the time of ryegrass seeding--even in the fall--for the earliest protection against new growth of weeds the herbicide is labeled to control. Consider these products if you need quick weed control on newly seeded turf.
Disease Control for Perennial Ryegrass
Perennial Ryegrass can fall victim to certain fungal lawn diseases in the spring, including leaf spot, brown patch, dollar spot, and rust. These diseases can be treated with a fungicide that is labeled for use on perennial ryegrass and for the treatment of the fungus affecting your turf.
Finding the right fungicides and herbicides for weed and disease control can be tough. The DoMyOwn Turf Box takes the guesswork out of lawn care by sending the products you need for your turf type and lawn size directly to your door as needed. Learn more about the program and the additional savings subscribers receive.
Perennial Ryegrass Pest Control
Your perennial ryegrass lawn can be home to several pests, but maintaining a healthy turf can cut down on pest insects and reduce the damage they might cause. Sod webworms and cutworms can be threats to ryegrass lawns. The moths that lay the eggs of these worms are actually attracted to the dark green color of this turf's blades.
Japanese beetles. thrips, and white grubs are some other common pests that can cause trouble in a ryegrass lawn. Look for an insecticide labeled for use in residential turf areas that includes control of the insect you have found on your lawn. If white grubs are the issue, consider the use of a milky spore treatment for control.
Browse our Lawn Care Guides to learn more ways to control the various pests, weeds, and diseases found in turf.
If you have any questions about the products or methods mentioned in this guide, give our lawn care experts a call at 866-581-7378 or email email@example.com.
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