This page has been created by Lindly Ray

There are two different categories in which all species of turfgrass are divided.

Warm Season Turfgrasses, which thrive when the median temperature is between 80 degrees Fahrenheit and 95 degrees Fahrenheit.
Cool Season Turfgrasses, which thrive when the median temperature is between 65 degrees Fahrenheit and 75 degrees Fahrenheit.
  • The area of the United States you live in, and its climate, affect which type of turfgrass best suits your needs.


http://www.usna.usda.gov/Gardens/faqs/turfgrassfaq2.html
http://www.usna.usda.gov/Gardens/faqs/turfgrassfaq2.html



Cool Season turfgrasses grow better during the cooler months of the year, such as March to early June and September to mid November. They are also better suited for cooler climates of the United States. There are two different types of cool climate areas in the United States.


growth-cool-season.jpg
http://www.american-lawns.com/grasses/grasses.html



The root and shoot growth of a cool season grass thrive during cooler times of the year, thus making it a cool season grass. The image above shows how the root and shoot growth of the grass change throughout the year.


The cool humid zone includes areas like the Northeast, the Midwest, and a some of the Pacific Northwest. Grasses best suited for these areas include: Bluegrass, Fescues, Ryegrass, and Bentgrass.

The other category of cool climate area in the United States is the cool arid zone. The cool arid zone encompasses almost all of the West Central part of the United States, excluding coastal regions. Almost any cool season turfgrass grows successfully in the cool arid zones so long as irrigation is available. If irrigation is not readily available, grasses like Wheatgrass and Canada Bluegrass can be used.


Warm Season turfgrasses grow better during the warmer months of the year, suck as April to mid October. They are also better suited for warmer climates of the United States. Just as cool climate areas have 2 different categories, warm climate areas have 2 different categories.

Typically, warm season climates have cold winters and warm to hot summers. Usually they also have regular intervals of rain throughout the summer months, but grasses will tolerate some extended periods of drought by going dormant.
Typical cool season grass types include:
  • Bentgrass
  • Kentucky Bluegrass
  • Rough Bluegrass
  • Red Fescue
  • Annual Ryegrass
  • Perennial Ryegrass


growth-warm-season.jpg
http://www.american-lawns.com/grasses/grasses.html


There are the warm arid regions, and the warm humid regions.

The warm arid region includes areas of the United States such as the greater part of Texas, the Southern parts of New Mexico, Utah, Nevada, and California. Grasses that grow well in this region include: Bermudagrass and Buffalograss, but any warm season grass can be successfully grown in this region if irrigation is available.

The warm humid region of the United States includes the "Southern" states like Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, and the Southernmost part of Virginia. Grasses that successfully grow in this region include: Bermudagraa, Zoysiagrass, Carpetgrass, Bahiagrass, and St. Augustinegrass.

The Transition Zone of the United States runs through the center of the Country extending from the Atlantic Ocean and ends just West of the Oklahoma Panhandle. This region of the United States is the hardest region to grow grass in because of its cold winter temperatures and hot summer temperatures. This being said, there is not one species of grass that is easily grown in this region.

Typical Transition Zone grass species include:

  • Kentucky Bluegrass
  • Tall Fescue
  • Perennial Ryegrass
  • Thermal Blue
  • Zoysiagrass

Shade Tolerance

The amount of shade, or exposure to sunlight, can drastically impact the success of growing grass. Different types/species of grass have different levels of shade tolerance.
In response to reduced sunlight, grass plants form more of an upright growth habit including thinner, longer leaves; shallower rooting; lower plant energy levels and becomes less dense.Some grass types have developed a tolerance or adaptation to reduced light levels, while others do not.

The table below shows which species of grass are shade tolerant and if they are a cool or warm season grass. The table is evidence that cool seasoned grasses are more shade tolerant than warm seasoned grasses. This makes sense considering that it is cooler in the shade than it is in the sun.
Ranking of turfgrass species according to shade tolerance:
Ranking
Cool-Season
Warm-Season
High
Fine Fescue

Rough Bluegrass
Annual Bluegrass
Medium
Tall Fescue
Centipedegrass
Perennial Ryegrass
St. Augustinegrass
Kentucky Bluegrass
Zoysiagrass
Creeping Bentgrass

Low


Bermudagrass


Sources:

http://www.landscape-america.com/grasses/shadetolerance.html

http://www.american-lawns.com/grasses/grasses.html