During the cold winter months, many lawns become dormant and brown. However, there are some types of grass that continue to grow even when temperatures drop. Knowing what grass grows the fastest in winter can help homeowners keep their lawns green year-round.
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Why does grass grow slower in winter?
Cool-season grasses like fescue and bluegrass naturally slow their growth in winter. The drop in temperature causes them to enter dormancy to preserve nutrients. Warm-season grasses like bermudagrass go completely dormant and brown during winter. Their growth halts when soil temperature drops below 55°F.
The reduced sunlight and shorter days of winter also slow photosynthesis in grass. This limits energy production and resources available for growth. Meanwhile, frost and freezing temperatures can damage and even kill grass plants.
What conditions promote winter grass growth?
Even in winter, some grasses can continue growing at a reduced rate if conditions are favorable:
- Sunlight – Areas that receive at least 4-6 hours of sun per day will allow for better growth.
- Soil temperature – Grass will be semi-dormant once soils drop below 45°F but can keep growing as long as frost does not penetrate deeper than the roots.
- Soil moisture – Grass still needs moisture to grow. Adequate rainfall or irrigation is important during winter dry spells.
- Insulation – Snow cover and leaf litter act as insulators, protecting grass from hard freezes.
- Fertilization – Applying a high-nitrogen fertilizer in fall can help grass maintain winter color and growth.
What types of grass grow best in winter?
The following cool-season grasses fare best in winter:
Tall fescue
Tall fescue (Festuca arundinacea) is a favorite for winter lawns due to its deep root system. The roots can reach down 6 feet or more in search of water and nutrients. This allows tall fescue to keep growing even during droughts and cold snaps.
Tall fescue has a clump growth habit with thick, coarse blades. It maintains a bright green color in winter if sunlight is adequate. It grows best in USDA Hardiness Zones 5-9.
Perennial ryegrass
Perennial ryegrass (Lolium perenne) shares many attributes with tall fescue. Its extensive root system makes it quite cold hardy and winter active. Perennial ryegrass also retains good winter color with a medium-green hue.
This grass tolerates cold better than most. It can withstand freezing temperatures as low as -15°F once established. Perennial ryegrass thrives in USDA Zones 4-7.
Fine fescue
Fine fescues like hard fescue (Festuca longifolia), sheep fescue (Festuca ovina) and creeping red fescue (Festuca rubra) grow densely to form lush, carpet-like lawns. Their many fine leaves create a texture ideal for shady lawns.
These fescues grow actively during winter in areas with adequate sunlight and moisture. Their shade tolerance allows them to do well under the canopy of dormant trees. Fine fescues perform best in USDA Zones 4-8.
Kentucky bluegrass
Kentucky bluegrass (Poa pratensis) is prized for its appealing dark green color and dense, carpet-like growth habit. It maintains some growth through winter, especially with adequate sunlight and soil moisture. This makes it a popular choice for overseeding warm-season grasses in winter.
Kentucky bluegrass does best in zones with cool, humid summers like the transition zone and northeastern states (Zones 3-6). It tolerates cold and freezing well when healthy.
Chewings and red fescue
Chewings fescue (Festuca rubra ssp. commutata) and red fescue (Festuca rubra) also exhibit excellent cold hardiness. They have fine-textured leaves but a slightly wider blade than other fine fescues. As low-maintenance bunch grasses, they continue growing through much of winter.
These grasses prefer partial shade but tolerate full sun with adequate moisture. They thrive in zones 4-7.
How to encourage winter grass growth
Proper lawn care and maintenance boost grass growth even during harsh winter conditions:
Fertilization
Fertilizing in fall with a phosphorus-free, nitrogen-rich fertilizer builds up root reserves. Roots use this energy to keep growing through winter. Applying 1 lb. of nitrogen per 1,000 sq. ft. in September and again in November promotes lush winter color and growth.
Mowing
Continue mowing until growth stops in late fall. Gradually raise mower height over time to a final winter cut of 3-4 inches. Taller grass insulates crowns and roots from extreme cold.
Aeration
Core aerate lawns at least once per year in early fall before overseeding. Aeration relieves soil compaction to allow better movement of water, air, and nutrients to roots.
Weed and thatch control
Control weeds and thatch buildup during the growing season through proper mowing, fertilization, weed killers, dethatching, or core aeration. Weeds and thatch compete with grass for light, water, and nutrients.
Overseeding
Overseeding thin or bare areas in fall allows new grass to establish before winter. The young grass then has a head start on growth in spring.
Irrigation
Water grass thoroughly before the ground freezes. Provide occasional irrigation during winter dry spells if rainfall is insufficient to moisten soil to a 3-4 inch depth.
Best winter grass by region
The ideal winter grass depends on climate and geographical location:
Cool regions (USDA zones 6-7)
- Tall fescue
- Perennial ryegrass
- Kentucky bluegrass
Cold regions (USDA zones 3-5)
- Tall fescue
- Perennial ryegrass
- Fine fescue blends
Transition zone (USDA zones 6-7)
- Tall fescue
- Perennial ryegrass
- Kentucky bluegrass
Upper South (USDA zones 7-8)
- Tall fescue
- Fine fescue
- Kentucky bluegrass
Grass growth rates by temperature
Growth rates vary for different grass species and cultivars at certain temperatures:
| Grass Type | Minimum Temperature | Optimum Temperature | Maximum Temperature |
|---|---|---|---|
| Tall fescue | 40°F | 60-75°F | 85°F |
| Perennial ryegrass | 40°F | 60-75°F | 85°F |
| Fine fescue | 35°F | 60-70°F | 75°F |
| Kentucky bluegrass | 35°F | 60-75°F | 80°F |
As the table shows, cool-season grasses can grow at cold temperatures as low as 35°F. Their peak growth occurs between 60-75°F during spring and fall. Growth declines rapidly above 80°F.
Other winter lawn care tips
A few other tips will keep lawns healthy through winter:
- Leave grass clippings on the lawn to provide insulation
- Use salt substitutes like beet juice to melt ice on walkways
- Repair any dead patches and reseed in fall
- Adjust pH to between 6.5-7.0
- Consider interchangeable attachments to clear snow without damaging grass
Conclusion
Tall fescue, perennial ryegrass, fine fescue blends, and Kentucky bluegrass remain the best choices for winter lawns. Their growth slows but does not stop during winter dormancy. Proper maintenance like fertilization, mowing, aerating, overseeding, and irrigating encourages continued growth. Grass kept actively growing through winter greens up faster in spring.
Focusing on cold hardy, winter-active species ensures a lush, green lawn year-round, even through the coldest months.