What is Cool Season Grass? A Guide to Green Winter Lawns

Cool-season grass may be an end result of your search. It is generally believed that the arrival of autumn and winter brings death and dormancy of plants, but that’s not always true especially in the case of cool-season grass.

Cool-season grasses are the type of grass that grows well in regions that face extreme cold winters and dry hot summers, because they have the best growing environment at temperatures ranging from 60-75 degree F.

It is generally observed that these cool-season grasses are well-suited for the areas that experience extreme temperature swings, mostly they are seeded although sod is available. They have tolerance against both freezing winters and dry, hot summers.

Here is all you need to know about cool-season grasses and its types, for year-round green lawns, with minimal maintenance and simple care tips.

Defining Cool-Season Grasses

Many people get confused about what are cool-season grasses?

The answer is that they are types of grass which grows best in regions of moderate temperatures. Generally having temperatures between 15 and 24°C is ideal for the best growth of cool-season grasses.

Identifying the right cool-season grass among so many grasses is sometimes hard, especially if you are new to the world of green grasses and gardening.

Identifying Cool-Season Grasses

For identifying cool-season grasses we need to observe their certain features. Physical characteristics like their pattern of growth and seasonal behavior towards weather conditions are important. Here are some tips that might help:

Cool-season grasses commonly have soft and medium blades which become lush green during their peak growth season, creating a thick mat like turf.
Cool-season grasses generally have active growth during spring and winter when temperatures are cooler (15–24°C), on other hand they may turn brown in hot summer months.
Cool-season grasses produce unique shaped seed heads in spring or early summers.

Observing the response of grass to seasonal changes can help in identifying cool-season grass.
Comparing the shape, color and size of leaf blades can also help.
Analyzing slow growth during summer heat is also a sign of cool-season grass.

Types of Cool-Season Grasses

During photosynthesis, the method of capturing carbon dioxide categorizes the type of grass as C3 or C4. Cool-season grasses fall in category C3 of plants, which are adapted to thrive well in cool weather.

Every category of grass has its own unique care and maintenance needs for its active, healthy and long-term growth. The early stages of growing cool-season grasses require a sheer dedication as at the primary stage of plantation. The newly planted grass needs daily care including regular watering and weekly trimming to help in proper and healthy germination.

Here are types of cool-season grasses along with their complete information and care tips to thrive your lawn.

Kentucky BlueGrass

Kentucky BlueGrass originally belonged to Europe and became popular in the US in the 1600s.
Kentucky bluegrass (KBG) is generally preferred by people living in northern states with cool temperatures.
Generally considered perfect for lush green lawns used in house lawns,sports fields, parks, golf courses and greenbelts along roadsides.
Requires regular and careful maintenance.

Growing Kentucky BlueGrass

Kentucky bluegrass has a higher growth rate.
It is mainly grown from seeds, though sods are also available for plantation.
It has a strong rhizome system but slow germination, that’s why it is mostly planted along with fast growing perennial ryegrass for fast growth.

Ideal Environment/Regions for Kentucky BlueGrass

Ideal choice for the areas that experience cold winters and moderate summers.
Popular choice in states like Michigan, Minnesota, Wisconsin, and New York.
Thrives well in sunny areas but can also survive in partial shady places.
Well-drained soil and moderate fertility levels provide a healthy environment for the success of cool-season grasses.
Regions with sufficient rainfall or consistent irrigation are preferable for best growth.

Identification of Kentucky BlueGrass

Kentucky Bluegrass are dark blue-green in color.
Its blades have boat-shaped tips having medium-texture, ranging width between 2-4mm.
Kentucky BlueGrass has folded vernation ( leaves are folded as they emerge).
Triangular-shaped seed heads are produced.

Benefits of Kentucky BlueGrass

Aesthetic appeal because of lush green turf
Drought tolerance,survives well in dry conditions
Good weed resistant
Tolerant to cold weathers
Recovers quickly from damage

Disadvantages of Kentucky BlueGrass

Requires high maintenance for better growth
Slow growth rate, takes very long to establish
Poor heat/ high temperature tolerant

Care Tips for Kentucky BlueGrass

Watering regularly boosts growth
Overseeding contributes to growth of lush green turf
Mowing regularly helps in maintaining grass’s health
Proper fertilization helps in pest and disease control, enhancing growth
Temperature management plays important role in thriving

Fine Fescue

Fine fescues are popular for their excellent tolerance against shade and drought.
Fine fescues are rarely used alone, mostly are mixed with other grasses like Kentucky bluegrass or perennial grass for better growth and boosted performance.
Fine fescues have four sub-categories namely: Creeping red fescue, Chewing fescue, Sheep fescue and Hard fescue.
The only spreading specie of fine fescue is Creeping red fescue having further two subtypes namely:

Slender creeping having short rhizomes
Aggressive creeping having strong rhizomes

Growing Fine Fescue

Fine fescues are mostly grown in bunch-like form, while some are grown through rhizomes that spread gradually.
Fine fescues are generally grown through seeding because of their fast germination rates.

Ideal Environment/Regions for Fine Fescue

Grows well in cool climates and shady areas.
Ideal choice for shaded lawns and cool summer regions.
Thrives well in cool-season and well-drained soil areas like Minnesota.
Needs very low maintenance and minimal care.

Identification of Fine Fescue

Fine fescues have bristle-like appearance
Have thin leaves having width less than 0.5 mm, more slender as compared to other grasses
Leaves have folded vernation Folded vernation
Have narrow collar structure

Benefits of Fine Fescue

Excellent shade tolerant
Survives well in dry condition
Minimal care and low maintenance

Disadvantages of Fine Fescue

Over-fertilization causes thinning
Intolerant to poorly drained soils
Thin appearance especially in bunches

Care Tips for Fine Fescue

Watering once or twice a week deeply promotes deep rooting
Mowing at 3-4 inches
Avoid over-cutting, not more than one-third
Avoid overfertilization
Maintain proper soil drainage

Tall Fescue

Tall fescue very famous cool-season grass
It is the most preferred choice for cool-season lawns, alongside Kentucky bluegrass
More preferred in low-maintenance areas and public space
Perfect choice for lawn in transition zones

Growing Tall Fescue

Tall fescue grows create a low-density turf
Can be grown by seeds and vegetation as well

Ideal Environment/ Regions for Tall Fescue

Thrives well in transition zones
Moderate climates and well-drained soils are suitable for growth
Tolerant to partially shaded areas
Preferable for limited water areas because of its tolerance against drought

Identification of Tall Fescue

Coarse textured with wide and thick blades ranging from 5-10 mm
Leaves have rolled vernation, producing narrow seed heads
Grows in clumps and bunches

Benefits of Tall Fescue

Good tolerance against foot traffic
Tolerant against drought and shade
Well thrived in summers and transition zones
Pest and disease tolerance

Disadvantages of Tall Fescue

Less appealing appearance due to coarse texture and clumpy growth
Low tolerance to harsh winters as compared to other cool-season grasses

Care Tips for Tall Fescue

Watering deeply once or twice a week
Avoid over-cutting, mow only at 2-4 inches
Overseeding in fall helps in thickness
Fertilize and aerate soil for proper growth

Creeping BentGrass

Ideal choice for golf courses in cold, northern regions
Creeping bentgrass is a high maintenance grass
Not suitable for residential areas because of its high care demands

Growing Creeping BentGrass

It is the fastest growing turfgrass
Grown with both seeds and vegetatively
Creates a dense, lush green and smooth textured lawn

Ideal Environment/Regions for Creeping BentGrass

Cooler regions and northern regions are ideal for its growth
Needs full sunlight and well drained soils for fast growth

Identification of Creeping Bent BentGrass

Rough edged blades with a width of 1-3 mm
Have dense and low growth
Shows rolled vernation and triangular shaped seed heads

Benefits of Creeping BentGrass

Suitable choice for areas like Canada because of its winter tolerance
Forms a thick, uniform lawn with quick wear recovery feature
Creates dense turf ideal for golf courses

Disadvantages of Creeping BentGrass

Demands high maintenance and regular mowing
Requires regular watering and significant fertilization
Highly prone to fungal diseases

Care Tips for Creeping BentGrass

Needs high care for proper growth
Regular mowing and regular watering boosts growth
Maintain balanced fertilisation with balanced mix
Ensure well-drained and aerated soil to promote healthy roots
To maintain turf quality dethatch periodically
Ensure full exposure to sunlight and monitor any pests and diseases

Perennial Ryegrass

Popular in cooler regions of US for home lawns
Generally mixed with fine fescues or Kentucky bluegrass because of its fast growth
Preferred for public places, warm-season lawns and golf courses

Growing Perennial Ryegrass

One of the fast growing turfgrass
Shows quick germination, seeds germinate in few days unlike other grasses that take weeks
Grown with seeds in form of clumps
Shows competitive growth and rapid establishment

Ideal Environment/Regions for Perennial Ryegrass

Cold winters and mild summers are ideal regions
Shows rapid growth in regions of consistent moisture
Ideal choice for high-maintenance areas
Thrives best in full sunlight and well-drained fertile soil

Identification of Perennial Ryegrass

Shows dense and bunch like growth, forming clumps
Leave blades show folded vernation, with blade’s width of 2-5 mm
Seed head is very narrow shaped and slim

Benefits of Perennial Ryegrass

One of the fastest growing cool-season grasses
Shows excellent wear and foot traffic tolerance
Ideal for prevention of soil erosion
Perfect for overseeding to dormant warm-season gardens

Disadvantages of Perennial Ryegrass

Requires high to medium upkeep
Needs sharp mowing at length of 1.5-2.5 inches
Intolerant to shade and drought
Comparatively less tolerant to harsh temperatures
Invasive in nature because of fast growth

Care Tips for Perennial Ryegrass

Water frequently for maintained moisture
Ensure full sunlight and balanced fertilization
Maintain well-drained, aerated and fertile soil
Dethatch regularly to maintain turf’s uniformity

FAQs:

What is the best cool-season grass?

Kentucky Bluegrass is most popular because of its color and cold tolerance while perennial ryegrass is best for its fast germination.

Can you mix warm and cool-season grasses?

Yes, you can mix warm and cool season grasses for overseeding to fix dormancy.

How do you know if you have warm or cool-season grass?

The main difference is between the active growing season; cool season grasses establish well in spring and winters while warm season grasses thrive well in summers.

What is the best height for cool-season grasses?

The height varies according to type like: Kentucky Bluegrass has ideal height of 2.5 to 4 inches, perennial ryegrass grows best at height of 2 to 3 inches and fescue maintains best height at 3 to 4 inches.