Ornamental · Poaceae
Perennial Ryegrass
Lolium perenne
Sow it and it's up in days, giving you fast, fine-bladed, hard-wearing turf that greens a lawn in a fortnight.
Full sun
Every 2–7 days
14–21 days
USDA 3–7
Overview
Want a lawn that comes up fast? Perennial ryegrass is a cool-season grass that's famous for exactly that. Drop the seed and the first blades show in 3 to 7 days, which beats every other common lawn grass, and that's why you'll find it in so many seed mixes and quick patch kits. The blades are fine to medium and a glossy dark green, and the turf takes a beating without much fuss, so it turns up on lots of sports fields and busy family lawns.
Here's the catch though: it grows in clumps instead of creeping outward. Since it's a bunch grass, it doesn't have rhizomes or stolons, so each plant stays put and a worn patch won't close up by itself. That's why a lot of people pair it with Kentucky bluegrass, which spreads by rhizome to fill in the gaps while the ryegrass brings the speed and toughness.
It likes things cool and it likes steady moisture, holding its green from a deep cold of -20°F (-29°C) all the way up to summer heat near 95°F (35°C), though it does get sulky in a real drought. Down South it pulls double duty as a winter overseed, sown over dormant warm-season lawns to keep them green until spring rolls around.
Care
The short version: full sun, steady moisture, and regular mowing to about 1.5 to 2.5 inches (4 to 6 cm). Feed it in spring and fall, go easy on nitrogen in the summer heat, and reseed any thin spots, because this grass won't fill them in on its own.
Light
Perennial ryegrass is happiest in full sun, but it'll take some partial shade too. The more sun it gets, the denser and tougher the turf, and a really shady spot just leaves it thin and weak.
Water
Keep a new seedbed consistently moist so it sprouts in 3 to 7 days, and water it lightly and often until the grass is up. Once it's established it still wants moderate to high water and slips fast in drought, so don't let it dry out for long.
Soil
Plant it in fertile, moist, well-drained soil. A pH of 6.0 to 7.0 suits it just right, and ground that drains freely but still holds a little moisture keeps the whole stand happy.
Temperature
Being a cool-season grass, it handles a big range, from about -20°F (-29°C) in winter up to roughly 95°F (35°C) in summer. It grows hardest in the cool of spring and fall, and it tends to slow down and struggle through real summer heat.
Humidity
Regular outdoor humidity is plenty, so there's no number to aim for. What actually matters is long spells of leaf wetness, because damp blades in warm weather are what open the door to gray leaf spot.
Feeding
Feed it with a balanced turf fertilizer in spring and fall, when it's growing hardest. Just go light on nitrogen in late spring and summer, since a flush of soft growth in the heat is what invites gray leaf spot.
Pruning
Mow it on a regular schedule to about 1.5 to 2.5 inches (4 to 6 cm). And if gray leaf spot shows up, bag and toss the clippings so you're not spreading the fungus all over the lawn.
Repotting
none
Size & spacing
Once it's mowed, the blades only stand about 2 inches (5 cm) tall, and each clump spreads out to roughly 6 to 12 inches (15 to 30 cm). Since it grows in bunches with no runners, sow the seed thick and even so the clumps knit together into solid turf.
When to plant
Perennial ryegrass is a cool-season grass, so it likes going down when the weather's mild instead of hot. Sow or overseed in early fall, or in spring if you're somewhere cool, and down South you can lay it over a dormant warm-season lawn in fall to carry the green through winter.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Seed or overseed in early fall (or spring) in cool-season regions; standard winter overseed for dormant warm-season lawns in the South.
- Harvest: Establishes uniform turf within about 2 weeks under ideal conditions.
Hardiness
USDA hardiness zones: 3–7
Temperature: down to -40°C
Troubleshooting
Most ryegrass trouble shows up as patches, and the weather usually gives away which problem you've got. Hot and humid points one way, cool and damp points another, and a plain worn gap points right back at the grass. Find what matches below, then jump on it before the patch spreads.
Greasy gray patches that trash the lawn in a hurry
This is gray leaf spot, and it's rough on perennial ryegrass when the weather turns hot and humid and the blades stay wet for hours. You'll see patches spread out 4 to 12 inches (10 to 30 cm) wide, the grass goes matted and gray-fuzzy, and honestly a whole stand can be gone in just a few days. So what helps? Bag the clippings, water before sunrise so the grass dries quickly, and lay down a preventive fungicide every 14 to 21 days through the risky part of the season.
Fix:
- Collect clippings when symptoms appear
- Apply preventive fungicide on a 14-21 day interval during high-risk periods
Bare spots that just sit there and don't grow back
Wondering why that worn patch never closes up? It's the growth habit. Perennial ryegrass is a bunch grass, so it grows in tidy clumps and has no runners to creep sideways and cover a gap. That means once foot traffic or rough weather thins a spot, it'll stay open until you do something about it. The fix is easy though: scatter fresh seed over the bare ground, or work in some Kentucky bluegrass, which spreads by rhizome and fills the gaps for you.
Fix:
- Overseed bare areas directly with fresh ryegrass seed
- Blend with Kentucky bluegrass so the bluegrass spreads to fill gaps
Pinkish patches with little red threads on the tips
Seeing round pinkish patches with tiny red strands on the blade tips? That's red thread, and it likes the cool, damp weather of spring and fall. Good news is it usually means the lawn's a bit hungry for nitrogen, not that it's seriously sick. Give it a balanced feed and the fresh growth outruns the fungus, and if you mow off the infected tips and ease up on evening watering, it clears right up.
Fix:
- Apply adequate nitrogen to push recovery growth
- Mow to remove infected tips and reduce leaf wetness
Toxicity
Good news, lawn ryegrass is safe. It's a common turf and pasture grass with no toxic parts, so cats, dogs, rabbits, birds, and kids are all fine around it. The one thing to know is a grazing thing, not a poison thing: pasture stands carrying a fungal endophyte can cause ryegrass staggers in horses and livestock, which is about managing the forage, not any danger in the lawn under your feet.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
No worries with cats. A few blades of lawn ryegrass won't hurt them, and plenty of cats chew a little grass anyway with no problem at all.
Dogs None
Dogs are totally fine here. Lawn ryegrass is on the non-toxic list, so they can play, roll around, and even graze a bit without a thing to worry about.
Horses None
The grass itself is fine to graze, so no real worries there. The one thing to keep an eye on isn't poison, it's pasture care: stands with a fungal endophyte can bring on ryegrass staggers, which shows up as muscle tremors and a wobbly, uncoordinated walk when the horse gets worked up.
Rabbits None
Rabbits can graze it, no problem. A bit of fresh lawn ryegrass fits right in with the other greens they're already munching.
Livestock None
It's grown as forage all over the place, so it's safe. The only thing to watch for is endophyte-infected pasture, where lolitrem B and ergovaline can cause staggering, poor coordination, and heat stress on stands that get grazed too hard in late summer and fall.
Birds None
Birds are fine around it too. They'll peck the seed and clippings without any harm, since there's nothing in the grass that could bother them.
People None
It's just an everyday lawn and pasture grass with no toxic parts, so kids can play on it all they like.
Safe as a pet and family lawn; however, turf-type and forage ryegrass can carry a fungal endophyte (Epichloe festucae var. lolii) producing lolitrem B and ergovaline that cause tremors, incoordination, and heat stress in grazing horses and livestock, especially on overgrazed stands in late summer and fall.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
There are a few kinds of perennial ryegrass floating around, and the labels are pretty easy to mix up. Here are the ones worth telling apart.
Turf-type cultivars
These are the improved picks, with a fine-to-medium texture and glossy dark green color, bred so the lawn stays dense and shrugs off wear.
Winter overseeding ryegrass
This is what folks in the South scatter over a dormant warm-season lawn to keep things green all winter long.
Distinct from annual/Italian ryegrass
Don't mix it up with annual ryegrass (Lolium multiflorum), which is coarser and short-lived, because perennial ryegrass is finer and hangs around for years.
Companions
Perennial ryegrass pairs best with a spreading grass that can do the one thing it can't, which is fill its own gaps.
Plant near
Kentucky bluegrass: Spreads by rhizomes to fill the gaps that bunch-type ryegrass cannot self-repair.
How to propagate
Perennial ryegrass grows from seed and not much else, since it doesn't make runners to root from. The nice part? Speed. Hardly any grass comes up as quick.
SeedEasy
Early fall (or spring) in cool regions; fall for southern winter overseeding. · Germinates in 3-7 days, the fastest of common lawn grasses; uniform turf in about 2 weeks.
Seed's pretty much your only option, since there aren't any runners to root from. Sow it in early fall or spring in cool regions, or in fall if you're doing a southern winter overseed. It'll pop up in 3 to 7 days, faster than any other common lawn grass, and knit into even turf in about 2 weeks. And since the clumps never spread on their own, just reseed the thin spots when you want to build things up.
Myths
Perennial ryegrass and annual ryegrass are the same plant.
Nope, they're actually two different grasses. Perennial ryegrass (Lolium perenne) is fine-textured and sticks around as permanent turf, while annual ryegrass (Lolium multiflorum) is coarser and short-lived, handy as a quick cover or a winter overseed. So check the species name on the bag before you buy.