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Pros and Cons of the Best Cool-Season Grasses

Seeding Lawn Basics
10 min read

There are five important cool-season grass families. Tall fescue, Kentucky bluegrass, perennial ryegrass, fine fescue and creeping bentgrass (used almost exclusively on golf course putting greens). Jonathan Green Black Beauty® Ultra Grass Seed contains three out of the five families. These grass varieties, bred by Jonathan Green turfgrass plant breeders, are some of the best on the market. This article analyzes the pros and cons of each of these grasses and why Jonathan Green combined them to make a superior grass seed blend. 

Tall Fescue

  • Heat, drought, and shade-tolerant
  • Withstands wear and tear 
  • Extensive root system
  • Bunch forming growth
  • Limited self-repair ability
  • Susceptible to disease
  • Suffers without water


Tall fescue is the most popular cool-season turfgrass because of its good looks and wide adaptability to many growing situations. It survives well in what are considered “cool/humid” climate zones which includes most of the northern half of the USA. The medium wide grass blades are very beautiful, exhibiting a uniform growth habit and shiny dark green leaves.

Tall fescue is very popular because its wear and tear tolerance is high and it withstands extreme temperatures. It survives in most places in the upper half of the US except for the northernmost portions of states such as Minnesota and Montana. The dark green, beautiful color makes lawns look lush and healthy. Its heat, drought and shade tolerance, as well as disease resistance, results in a high demand for this grass seed.

Tall fescue also has a “bunch forming” growth habit, which is both a positive and negative attribute. It spreads through tillers, or individual grass shoots that grow from the base of the plant. On the upside, the bunch forming growth pattern makes it easy to keep out of garden beds and it rarely needs dethatching. On the downside, it has a limited ability to self-repair.

Tall fescue is also known for its extensive root system, Jonathan Green Black Beauty® varieties can grow roots up to four feet deep! Additionally, it adapts to many different soil types and requires less fertilizer than other cool-season grasses.


Tall fescue has very few drawbacks. It is quite drought tolerant but suffers if it doesn’t receive appreciable water for over 100 days. Tall Fescue is also susceptible to brown patch disease in regions that are very hot and humid. Although snow mold disease is possible during wet and cold early spring weather, it recovers when temperatures warm up and the sun shines again. Also, as mentioned above it has a limited ability to self-repair. Overall, however, tall fescues make beautiful, healthy-looking lawns. 

Where Black Beauty® Tall Fescue Performs Best

Kentucky Bluegrass

  • Dense growth
  • Excellent ability to self-repair 
  • Survives cold temperatures
  • Recovers from dormancy
  • Shallow roots
  • Cannot survive in shade
  • Germinates slowly


Kentucky bluegrass, or KBG, is another popular type of cool-season grass. It is identifiable by its boat shaped leaf tip, like the prow of a canoe. The folded blade and central rib running down the middle of the leaf are easy to spot. Its blade is narrower than tall fescue but it has a similar dark green color making it beautiful to look at and comfortable to walk on. 

Although Kentucky bluegrass is narrow, it grows densely. The number one difference between tall fescues and bluegrasses is in the way they grow. KBG has a rhizome structure that grows horizontally, meaning its ability to spread is wonderful, its self-repair capacity is excellent and its dense formation is ideal for sod use. It also survives better in colder temperatures than other cool-season grass types. Lastly, it has an excellent ability to recover from dormancy brought on by extended drought stress. These characteristics make it suitable for the northern half of the US, like tall fescue. 


Due to its shallow root system, KBG needs a fair amount of water to survive, especially in the summer months. Frequent and deep irrigation will help prevent it from going dormant though. It does not do well in densely shaded areas, because it requires a good bit of sun. Also, Kentucky bluegrass germinates and grows the slowest out of all three of the grasses in this article. The wait is well worth it though! The rich blue-green color of this grass will make the neighbors take notice and improve the appearance of the house.

Perennial Ryegrass

  • Germinates very quickly
  • Nurse plant
  • Strong wear and tear tolerance
  • Maintains color in winter
  • Grows in thin
  • Cannot survive extreme weather
  • Limited capacity to self-repair


Perennial ryegrass is best known for its beautiful shining green color and quick germination. It is easily spotted even when mixed in with other grass types. There is a misconception that ryegrass is suitable only for temporary lawns. Perennial ryegrass, however, especially the variety that is in Black Beauty® Ultra, comes back beautifully year after year.

Perennial ryegrass has many advantages. As mentioned above, it germinates quicker than most other grass types. In grass seed mixtures it is able to provide shade and protection for the other grasses that take longer to grow making it a good nurse plant. It also has a high wear tolerance, including its ability to survive low mowing. It is an allelopathic plant meaning that it naturally suppresses other plants from growing. This is positive because it can help prevent crabgrass from emerging. Finally, its ability to withstand shade and maintain its color in winter months makes it a great addition to grass blends.


Although perennial ryegrass has its advantages there are a few downsides to it. It grows in quite thin, not dense like Kentucky bluegrass. It also cannot survive extreme temperatures and requires maintenance regarding bare patches. Perennial Ryegrass only spreads its root system a short distance so it does not fill in bare spots as well as Kentucky bluegrass. However, it works very well in conjunction with other grasses which is why it is in the Black Beauty® Ultra Grass Seed Blend.


Although all of these grass types have some individual weaknesses, together they make a great team! This is why Jonathan Green uses these three grass types in Black Beauty® Ultra. Based upon the percentage by weight, Black Beauty® contains 80% tall fescue, 10% Kentucky bluegrass, and 10% perennial ryegrass, resulting in an amazing looking lawn. 

It is common to combine turfgrasses because the result is stronger and more impressive than their individual components could produce. The perennial ryegrass is very dark green and blends in with the tall fescue and Kentucky bluegrass. It is also a nurse grass, holding the other grasses in place so they have time to establish and don’t wash away. The perennial ryegrass germinates in five to seven days. This motivates homeowners to continue watering and caring for their lawns as the other two kinds of grass germinate and grow. The tall fescues germinate next in about 14 days and the Kentucky bluegrass in approximately 21 days. 

The Kentucky bluegrass’ rhizome root system knits the grass plants together making them stronger and fills in bare spots. The perennial ryegrass also has good abrasion resistance or wear tolerance. The tall fescues take the longest to grow their deep four foot roots but they are the most drought tolerant and disease resistant. Together all three turfgrasses make a great lawn that is very uniform in texture and color. 

The waxy coating on this grass lowers the evapotranspiration rate, meaning water evaporates more slowly. The grass plant can then preserves water for periods of high heat and drought. Black Beauty® grass is also endophytic, making it naturally insect resistant. These superior turfgrass varieties will improve even the poorest lawns once they are over-seeded into it. 

Jonathan Green uses two tests to evaluate the turfgrass breeding candidates on research farms to create superior grass seed. Dr Xuan Zhang of Virginia Polytechnic Institute and State University (VPI) developed these tests to measure a plant’s ability to create food and antioxidants. The theory is that plants with a better ability to create food and antioxidants perform better under times of stress, and are less susceptible to disease. Jonathan Green uses both of these tests to cull the list of our turfgrass breeding candidates. By doing so we eliminate the weaker plants much faster and spend more time breeding with the superior grasses. Due to these tests, our grass seed has outperformed it’s competitors. 

Overall, tall fescue, Kentucky bluegrass, and perennial ryegrass, particularly the varieties in Black Beauty® Ultra Grass Seed, are the best turfgrasses on the market today. The combination of these three varieties of grass will make any lawn look beautiful and healthy.

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