Kentucky Bluegrass

Poa pratensis

Family: Poaceae (poh-AY-see-ee) (Info)
Genus: Poa (POH-ah) (Info)
Species: pratensis (pray-TEN-sis) (Info)



Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun


Unknown - Tell us

Foliage Color:



under 6 in. (15 cm)

6-12 in. (15-30 cm)

12-18 in. (30-45 cm)

18-24 in. (45-60 cm)


Unknown - Tell us


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

Where to Grow:

Unknown - Tell us


Pollen may cause allergic reaction

Bloom Color:

Chartreuse (yellow-green)

Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Other details:

Unknown - Tell us

Soil pH requirements:

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

7.9 to 8.5 (alkaline)

Patent Information:


Propagation Methods:

From seed; direct sow outdoors in fall

Seed Collecting:

Unknown - Tell us


This plant is said to grow outdoors in the following regions:

Wellington, Colorado

Rehoboth Beach, Delaware

Glen Ellyn, Illinois

Iowa City, Iowa

Paducah, Kentucky

Galena, Maryland

Battle Creek, Michigan

Brainerd, Minnesota

Oswego, New York

Downingtown, Pennsylvania

Lewisburg, Pennsylvania

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Gardeners' Notes:


On Jun 5, 2015, coriaceous from ROSLINDALE, MA wrote:

This is a water-hog cool-season grass. Not recommended where the average July temperature is over 75F.

Best here (Boston Z6a) in spring and fall. 50 years ago most people were content to let it go dormant in the heat of summer. (It's easily damaged by foot traffic when dormant.) Not any more.

To avoid having it choked out by crabgrass, the best time to lay down seed here is when the heat of summer begins to moderate, from mid-August through mid-September. That's also the best time for overseeding. Most people try to seed in spring, and then wonder what they did wrong.

Most authorities now recommend mowing lawns no shorter than 3". Cutting any shorter encourages weeds by allowing more sunlight to reach the soil surface.

Best with s... read more


On Jun 4, 2015, Rickwebb from Downingtown, PA wrote:

This is the most commonly planted or sodded lawn grass in the northern USA. It has a nice fine texture and many cultivars. It is also a common pasture grass, as it was first brought from Europe to be that. it and Tall Fescue are the most common grasses in meadows in the northern US with some other Eurasian plants as Wild Carrot, Sweetclover, and several others. American native grasses are found in pioneer cemeteries and some land preserves where they are managed with fire to keep it native. I've always had mostly Kentucky Bluegrass lawn where I have lived in Illinois and Pennsylvania. I like some lawn for walking around and having a sitting area, but there is too much lawn in the USA. A lot of lawn is not good ecology as it absorbs less carbon dioxide and releases less oxygen than other pl... read more


On Feb 25, 2012, Clary from Lewisburg, PA (Zone 6b) wrote:

Our grass looks best in spring and fall. In fact, I usually have a green lawn until it snows, and at spring thaw you can see that growth has already started. This grass requires a lot of water, a lot of lime, regular mowing to maintain 1.5", annual aeration, and a few applications of fertilizer through the season.

Regarding MOWING SHORT: popular recommendations to mow at the highest setting or to mow more than 1.5-2" high don't provide the results claimed (such as reduced weeds). Letting the grass grow long, especially this grass, results in long thatch growing at the base of the stem and reduces the light available to other grass leaves. Mowing high results in more weeds because they are sheltered at ground level, and most lawn weeds are creepers.

MOWING SH... read more


On Aug 18, 2011, Cindy_Rae from Kansas City, MO (Zone 6a) wrote:

paani-We've tried Kentucky Bluegrass without any success. I read how pretty a green it is and thought we just HAD to have it.
We have 2 Black Walnuts out back and several others I'm trying to control and have been unsuccessful in growing any grass under them, except of course weeds and prairie grasses! :D
However, to be fair, the grass hasn't done too well here (KCMO) except in the cooler early spring and late fall. Apparently if I had researched further, I would've found that it doesn't like our excessive heat during the summer. If you put a ridiculous amount of water on it throughout the summer it will do a bit better, but it's definitely a cool-season grass.
MO Conservation says Buffalo Grass-a native grass, is a good alternative for lawns & only has to be mowed a ... read more


On Jan 30, 2011, paani from Saint Louis, MO (Zone 6a) wrote:

An Ohio State U. Extension Factsheet (HYG-1148-93) says, "The beneficial effect of black walnut on pastures in encouraging the growth of Kentucky bluegrass (Poa pratensis L.) and other grasses appears to be valid as long as there is sufficient sunlight and water." (quoted by Tom Clothier - ).

Does anyone know if Kentucky Bluegrass will actually grow within the radius of a black walnut? Or would you still have that no-grass circle under the walnut tree?