Perennial Ryegrass Care Calendar

Month-by-month care schedule for Perennial Ryegrass lawns. Fast-germinating, low thatch, and easy to overseed — your complete seasonal guide.

Mowing
1.5-2.5"
Annual N
2-4 lb N/1K sqft
Water
1-1.5 inches/week
pH
6.0-7.0
10
What to do now

October

Active Growth
Second fall nitrogen (0.5-1 lb N/1K sqft)
FertilizerHigh
Continue regular mowing at 2-2.5"
MowingHigh
Apply fall pre-emergent if not overseeding (prodiamine)
Weed ControlMed
Remove fallen leaves promptly
GeneralMed

PRG is thriving in fall temps. Continue mowing and feeding. If you overseeded in September, the new seedlings should be established enough to mow by now.

See the full Perennial Ryegrass pre-emergent application timing guide

Full Year Calendar

Every task, every month. Tap a month to see what's on the schedule.

January

Dormant
Soil test if not done in 3 years
Sharpen mower blades and service equipment
Order spring supplies (pre-emergent, fertilizer, seed)

PRG is dormant or semi-dormant. Use this time to plan spring overseeding — PRG thins over time and needs regular reseeding to stay dense.

February

Dormant
Apply lime or sulfur based on soil test results
Monitor for snow mold damage as snow melts
Service irrigation system

Adjust soil pH toward 6.0-7.0 range per test results. PRG may show some green growth on warmer days but is not yet actively growing.

March

Active
Apply pre-emergent before soil temps hit 55°F (4" depth)!
Begin mowing at 2-2.5" as growth resumes!
Rake out dead spots and debris

Pre-emergent must be down BEFORE soil reaches 55°F — it needs activation time. PRG resumes growth earlier than KBG in spring. Skip pre-emergent in areas you plan to overseed this spring.

April

Active
First nitrogen application (0.5 lb N/1K sqft)!
Mow every 5-7 days at 2-2.5"!
Spot-treat broadleaf weeds (2,4-D, triclopyr, or dicamba)

PRG responds quickly to spring nitrogen. Keep mowing consistent — never remove more than 1/3 of blade height per mow.

May

Active
Second nitrogen application (0.5 lb N/1K sqft)!
Mow regularly every 5-7 days at 2-2.5"!
Begin irrigation — PRG needs consistent moisture!
Apply preventive grub control (GrubEx / imidacloprid)

PRG is at peak spring growth. Begin supplemental watering — PRG has LOW drought tolerance and will be the first grass to wilt in a mixed lawn.

June

Active
Raise mowing height to 2.5"!
Water 2-3 times per week — PRG wilts faster than fescue!
Apply iron supplement for color instead of heavy nitrogen
Watch for gray leaf spot — avoid heavy nitrogen in heat

Raise mow height to help PRG handle summer heat. Gray leaf spot thrives in hot, humid conditions — excess nitrogen makes it worse. Iron gives color without disease risk.

July

Active
Maintain mowing at 2.5" every 5-7 days!
Water consistently — PRG has LOW drought tolerance!
Avoid heavy nitrogen applications
Monitor for brown patch in humid conditions

Summer stress period for PRG. Keep watering consistent — PRG will go dormant or die in extended drought faster than fescue or KBG. Light iron only, no heavy N.

August

Active
Continue consistent summer watering!
Late August: prepare for fall overseeding (mow low, dethatch)!
Scout for sod webworms (irregular brown patches, moths at dusk)

Late August is the start of PRG's best window. Begin preparing thin areas for overseeding — mow short, dethatch or core aerate to improve seed-to-soil contact.

September

Active
Overseed thin areas (3-4 lb/1K sqft) — PRG germinates in 5-10 days!
Core aerate before or during overseeding!
Heavy fall nitrogen (1 lb N/1K sqft)!
Keep overseeded areas consistently moist!

PRIME TIME for PRG. September is the single most important month — overseed, aerate, and feed heavily. PRG's fast germination (5-10 days) means you'll see results within two weeks. Keep new seed moist but not soggy.

October

Active
Second fall nitrogen (0.5-1 lb N/1K sqft)!
Continue regular mowing at 2-2.5"!
Apply fall pre-emergent if not overseeding (prodiamine)
Remove fallen leaves promptly

PRG is thriving in fall temps. Continue mowing and feeding. If you overseeded in September, the new seedlings should be established enough to mow by now.

November

Active
Final winterizer nitrogen application (0.5-1 lb N/1K sqft)!
Lower mowing height for final cut of the season
Clear leaves — smothered PRG dies out over winter!

Winterizer is the last nitrogen app of the year. It feeds root growth through late fall and gives PRG stored energy for early spring green-up. Remove leaves — PRG is clump-forming and smothers easily.

December

Dormant
Equipment maintenance and storage
Review soil test and plan spring inputs
Order seed for spring overseeding if needed

PRG is dormant or semi-dormant. Plan for next year — remember PRG thins naturally and will likely need overseeding again in fall.

Quick Reference

Mowing Height

1.5-2.5"

Dormant when ground freezes. Green-up at 45°F air temp.

Watering

2-3 times per week during active growth, daily during summer heat waves

0.5 inches per session (1-1.5 inches total per week) per session. Perennial ryegrass has LOW drought tolerance — consistent moisture is critical. It will be the first grass to show drought stress in a mixed lawn. Water early morning only.

Fertilizer Program

2-4 lb N/1K sqft/year

Soil pH target: 6.0-7.0

Pests & Weeds to Watch

White GrubsCrabgrassSod WebwormsBillbugsDandelionCloverAnnual Bluegrass (Poa annua)

Want the full Perennial Ryegrass guide?

Read the complete Perennial Ryegrass care guide — quick facts, mowing heights, safe products, and the agronomy behind every recommendation.

Read the Perennial Ryegrass care guide

Want to compare all cool-season grasses side by side?

See the full Cool Season Calendar

Frequently Asked Questions

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Perennial Ryegrass in other climate zones

The calendar above is for the transition zone (USDA 7 to 8). Perennial Ryegrass is also grown in the zone below, and the timing is genuinely different — soil temperature in the transition zone runs three to five weeks behind the south, which moves pre-emergent, fertilizer and aeration with it. Find your zone and work from that table.

Growth status and soil temperature are derived from each zone's soil curve together with Perennial Ryegrass's own dormancy and green-up thresholds, so they describe that zone rather than an average of all of them.

Perennial Ryegrass in the North — USDA 6 and colder

The upper Midwest, New England and the Pacific Northwest. A short season with a hard winter, so the autumn window closes earlier and matters more.

Month-by-month Perennial Ryegrass lawn care schedule for the north zone
MonthGrowthMowWhat to doWhat you can skip
Januarydormant
~28°F soil, cooling
Not this month — the lawn is dormant.
  • Service the mower
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Februarydormant
~28°F soil, steady
Not this month — the lawn is dormant.
  • Service the mower
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Marchwaking up
~36°F soil, warming
1.5–2.5"
weekly
  • Soil test
  • Clear winter debris and check for snow mold
—
Aprilwaking up
~46°F soil, warming
1.5–2.5"
weekly
  • First mow of the season
  • Mow on a routine
  • Light spring nitrogen — 0.5 lb N per 1,000 sq ft
  • Spring pre-emergent, before the soil hits 55 F — per label for your grass and your square footage — these products are rated by season-long residual, so the label rate IS the decision — don't spray above 90°F
—
Maypeak growth
~56°F soil, warming
1.5–2.5"
every 5-7 days (every 2-3 days at low cuts)
  • Mow on a routine
  • Last spring fertilizer — your final chance before autumn — 0.5 lb N per 1,000 sq ft
  • Spot-treat broadleaf weeds — don't spray above 90°F
  • Aeration — cool-season aeration is a September and October job.
Junepeak growth
~66°F soil, warming
1.5–2.5"
every 5-7 days (every 2-3 days at low cuts)
  • Mow on a routine
  • Raise the mow height for summer
  • Aeration — cool-season aeration is a September and October job.
Julysummer stress
~74°F soil, warming
2–2.5"
only as needed — never remove more than a third of the blade
  • Iron for color — no nitrogen
  • Watch for brown patch
  • Plan the autumn renovation now
  • Granular or slow-release fertilizer — do not feed a cool-season lawn in summer heat.
  • Aeration and overseeding — both belong in autumn, not now.
  • Chasing perfection. Summer is about keeping the lawn alive; it recovers in September.
Augustsummer stress
~74°F soil, steady
2–2.5"
only as needed — never remove more than a third of the blade
  • Soil test
  • Iron for color — no nitrogen
  • Watch for brown patch
  • Plan the autumn renovation now
  • Granular or slow-release fertilizer — do not feed a cool-season lawn in summer heat.
  • Aeration and overseeding — both belong in autumn, not now.
  • Chasing perfection. Summer is about keeping the lawn alive; it recovers in September.
Septemberpeak growth
~64°F soil, cooling
1.5–2.5"
every 5-7 days (every 2-3 days at low cuts)
  • Mow on a routine
  • Drop the mow height back for autumn
  • The main nitrogen application of the year — 1 lb N per 1,000 sq ft
  • Core aerate
  • Overseed — 3-4 lb seed per 1,000 sq ft for overseeding; 6-8 lb for a new lawn
  • Fall pre-emergent for Poa annua — optional, and skip it if you are overseeding — per label. One application at the full label rate is the normal programme — don't spray above 90°F
  • Spot-treat broadleaf weeds — don't spray above 90°F
—
Octoberslowing
~52°F soil, cooling
1.5–2.5"
weekly
  • Lime, if the soil test called for it — per soil test; 50 lb per 1,000 sq ft raises pH roughly half a point
  • Mow on a routine
  • Winterize the irrigation system
  • Late autumn nitrogen — 0.5-1 lb N per 1,000 sq ft
  • Core aerate — last chance this year
  • Spot-treat broadleaf weeds — don't spray above 90°F
  • Keep leaves off the lawn
—
Novembergoing dormant
~40°F soil, cooling
1.5–2.5"
one last cut, once growth has stopped — then put the mower away
  • Final mow of the season
  • Keep leaves off the lawn
—
Decemberdormant
~32°F soil, cooling
Not this month — the lawn is dormant.
  • Service the mower
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.