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
Perennial ryegrass shoots out of the ground faster than just about any lawn grass a grower can plant, and that head start is half the fun. Sow it and the first blades push up in 3 to 7 days, beating every other common lawn grass, which is exactly why it fills so many seed mixes and quick patch kits. The blades run fine to medium in a glossy dark green, and the turf soaks up hard wear, so it thrives on sports fields and busy family lawns alike.
It grows in tight clumps instead of creeping outward, and that habit shapes everything about it. As a bunch grass it carries no rhizomes or stolons, so each plant digs in where it lands and a worn patch will not close on its own. Smart growers team it with Kentucky bluegrass to solve that, letting the bluegrass spread by rhizome and fill the gaps while the ryegrass brings the speed and the muscle.
It thrives in the cool and drinks steady moisture, holding a rich green from a deep cold of -20°F (-29°C) clear up to summer heat near 95°F (35°C), though a real drought knocks it back. Across the South it pulls off a clever second act as a winter overseed, scattered over dormant warm-season lawns to keep them green and growing until spring.
Care
The short version: full sun, steady moisture, and regular mowing to about 1.5 to 2.5 inches (4 to 6 cm). Feed in spring and fall, keep nitrogen light in the summer heat, and reseed thin spots, since this grass will not fill them on its own.
Light
Perennial ryegrass powers up in full sun and still takes some partial shade. Pile on the sun and the turf grows denser and tougher, but stick it in deep shade and it turns thin and weak.
Water
Keep a new seedbed consistently moist and it rockets up in 3 to 7 days, so water lightly and often until the grass is standing. Established turf still wants moderate to high water and drops off fast in drought, so never let it bake dry for long.
Soil
Plant it in fertile, moist, well-drained soil and it takes off. A pH of 6.0 to 7.0 hits the mark, and ground that drains freely while holding moisture keeps the stand charging along.
Temperature
As a cool-season grass it handles a huge 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 downshifts through the punishing heat of high summer.
Humidity
Everyday outdoor humidity does the job, so there is no number to chase. The real watch-out is long spells of leaf wetness, since damp blades in warm weather throw the door wide open to gray leaf spot.
Feeding
Feed with a balanced turf fertilizer in spring and fall, right when the grass is charging hardest. Ease off, though, and keep nitrogen light in late spring and summer, since a burst of soft growth in the heat invites gray leaf spot.
Pruning
Mow on a steady schedule to about 1.5 to 2.5 inches (4 to 6 cm). If gray leaf spot crops up, bag and haul off the clippings so you do not fling the fungus across the whole lawn.
Repotting
none
Size & spacing
Mowed down, the blades stand just about 2 inches (5 cm) tall, and each clump spreads 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 into one solid, springy turf.
When to plant
Perennial ryegrass runs cool-season, so it takes off when the weather is mild instead of hot. Sow or overseed in early fall, or in spring in cool regions, and across the South scatter it over a dormant warm-season lawn in fall to keep green rolling through the 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 breaks out as patches, and the weather usually hands you the answer. Hot and humid points one way, cool and damp another, and a plain worn gap points straight back at the grass. Match what you see below, then jump on it before a patch takes off.
Greasy gray patches that race across the lawn
Move quick on this one, because gray leaf spot hammers perennial ryegrass the moment the weather turns hot and humid and the blades stay wet for hours. The patches balloon 4 to 12 inches (10 to 30 cm) wide, the grass mats down gray and fuzzy, and a whole stand can crash within days. Fight back with a clear routine: bag every clipping, water before sunrise so the grass dries fast, and put down a preventive fungicide every 14 to 21 days straight through the danger months.
Fix:
- Collect clippings when symptoms appear
- Apply preventive fungicide on a 14-21 day interval during high-risk periods
Bare patches that wait for a fresh scatter of seed
Here is the quirk that keeps growing this grass interesting: perennial ryegrass is a bunch grass, so it packs into tight clumps and never sends out runners to crawl across a gap and patch it. Let traffic or a rough season wear a spot thin and it stays open, plain as day, until you step in. Grab a handful of fresh ryegrass seed and scatter it right over the bare ground, or team it up with Kentucky bluegrass, which spreads by rhizome and races in to close the gaps.
Fix:
- Overseed bare areas directly with fresh ryegrass seed
- Blend with Kentucky bluegrass so the bluegrass spreads to fill gaps
Pink patches sporting tiny red threads at the tips
Spot round pink patches trailing little red strands off the blade tips and you have caught red thread, a cool-and-damp visitor that pops up in spring and fall. Take heart, because it usually just flags a lawn running low on nitrogen, not a serious sickness. Push a balanced feed and fresh growth surges past the fungus, then mow off the infected tips and back off evening watering to send it packing.
Fix:
- Apply adequate nitrogen to push recovery growth
- Mow to remove infected tips and reduce leaf wetness
Toxicity
Great news for a busy household: lawn ryegrass is safe. It is a common turf and pasture grass with no toxic parts, so cats, dogs, rabbits, birds, and children play on it worry-free. The one thing to file away is a grazing caveat, not a poison: pasture stands carrying a fungal endophyte can bring on ryegrass staggers in horses and livestock, a forage-management matter and never a danger in the lawn under your feet.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats can nibble away with zero worry. A few blades of lawn ryegrass do nothing to them, and plenty of cats chew a bit of grass now and then and bounce right along.
Dogs None
Dogs get the all-clear here. Lawn ryegrass sits on the non-toxic list, so they can tear around, roll, and graze a little with nothing to fear.
Horses None
The grass itself grazes just fine, so relax on that front. The one thing to track is pasture care, not poison: stands carrying a fungal endophyte can spark ryegrass staggers, showing up as muscle tremors and a wobbly, uncoordinated gait once the horse gets fired up.
Rabbits None
Rabbits munch it happily. A little fresh lawn ryegrass drops right in with the greens they already love.
Livestock None
It is a trusted forage grown far and wide. Just keep an eye on endophyte-infected pasture, where lolitrem B and ergovaline can trigger staggering, poor coordination, and heat stress on stands grazed too hard in late summer and fall.
Birds None
Birds are in the clear. They peck the seed and clippings without harm, since the grass carries nothing toxic to them.
People None
It is a common, harmless lawn and pasture grass with no toxic parts, so let the kids run and play across it all day.
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
A handful of perennial ryegrasses show up on the shelf, and the labels blur together fast. Here are the ones worth pulling apart.
Turf-type cultivars
Improved picks that pack a fine-to-medium texture and a glossy dark green color, bred to build dense lawns that shrug off hard wear.
Winter overseeding ryegrass
The Southern trick of scattering it over a dormant warm-season lawn to keep the yard bright green clear through winter.
Distinct from annual/Italian ryegrass
Do not lump it in with annual ryegrass (Lolium multiflorum), a coarser, short-lived grass, because perennial ryegrass runs finer and sticks 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 pretty much nothing else, since it sends out no runners to root from. The payoff is speed, and few grasses launch as fast.
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 is the way in, plain and simple, since this grass sends out no runners to root from. Scatter it in early fall or spring in cool regions, or in fall for a southern winter overseed, and watch it burst up in 3 to 7 days, faster than any common lawn grass out there. It weaves into even turf in about 2 weeks. The clumps never spread on their own, so keep a bag of seed handy and reseed thin spots to build the stand up thick.
Myths
Perennial ryegrass and annual ryegrass are the same plant.
Not a chance, these are two different grasses. Perennial ryegrass (Lolium perenne) is a fine-textured turf that stays for the long haul, while annual ryegrass (Lolium multiflorum) is coarser and short-lived, handy as a fast temporary cover or a winter overseed. Scan the species name on the bag before you buy.