Big Bluestem – Facts, Identification, How to Grow

Big Bluestem is a tall perennial ornamental grass that is native to North America. Reaching heights of 10′ (3.3 m) in optimum conditions, it has multiple colors/shades to it throughout the season. Starting at blueish green in Spring, it will grow relatively fast finally settling on a shade of brown to tan in the Fall. So, it is a warm-season clump forming grass. Also, it is an important grass for wildlife, there are many insects that will feed on the foliage including skippers and over a dozen grasshoppers. Additionally, various small birds also consume the seed as well.

Big Bluestem in Mid-Summer, surrounded by Swamp Milkweed.

This plant is absolutely gorgeous when swaying in the breeze. It almost seems to be dancing when moving back and forth on a windy Autumn day. In my experience I’ve found that during heavy rains this plant may be drooping heavily the next morning, only to recover a day later and once again stand tall. This plant is really an interesting ornamental grass to have a specimen, or dispersed in a backyard prairie or wildflower garden.

Big Bluestem Facts

It is the tallest of the North American prairie grasses
Big Bluestem is hardy from zones 3-9
Is very valuable forage for cattle, bison, other mammals
The foliage is also eaten by many beneficial insects, giving this plant high ecological value
Native Americans chewed the root for stomach pains
The grass by itself, when dried was used by Native Americans in a variety of ways
Big Bluestem is deer resistant
The Scientific Name of Big Bluestem is Andropogon gerardii

Big Bluestem Identification and Physical Description

This tall perennial grass that is blueish green during the Spring and Summer, and eventually turns to gold/brown tan. By August it should be reaching its maximum height for the growing season, which in optimum conditions (full sun, moist soil) should be 8-10′.

Stalk / Stem

Very erect and large, the stalks of Big Bluestem all emanate form a central clump.

Leaves

Leaves are long and slender, being only 1/2″-1″ across but 10″ long or more. They wrap around the stalk by more than 50% of the stalk diameter.

Flower

The flower of Big Bluestem is paired spikelets that occur along the upper stems of the stalk. The top of the stalk will split into 3 smaller stems, each containing dozens of spikelets. The color is reddish-purple when blooming. The color will change to a golden brown in Autumn.

Root

Roots of Big Bluestem consist of short rhizomes that go a couple inches deep, and fibrous roots that can extend 10′ deep in the soil. Most of the root mass is concentrating in the top 1-2′ of the soil. Interestingly, recent studies are suggesting that the deep roots don’t seem to be that important for water uptake. So perhaps the extremely deep roots serve another primary purpose?

Growing Conditions for Big Bluestem

Big Bluestem grows best in full sun and slightly moist soil. It can take dry conditions also, but may not be as tall and vigorous. It is quite versatile in that it can grow in almost any soil type, from clay to loam, and even slightly sandy. This was the most dominant prairie grass for it size and versatility. The optimum temperature for Big Bluestem to grow has been found to be 25 Celsius, or 77 Fahrenheit. So if temperatures are below or above this it will grow slower. How much slower will depend on the temperature.

How to care for Big Bluestem

If you grow this in conditions that it prefers (full sun, moist soil) then you will have virtually no problems growing healthy plants. It requires basically no care.

Maintenance

In Spring when insects are waking up, you can cut down and remove the stalks/foliage from the previous season. You can do this earlier, however there may be beneficial insects wintering inside the large stalks. So, I always suggest waiting until Spring temperatures have warmed sufficiently to where any larva would have emerged.

How to Establish Big Bluestem

Growing Big Bluestem from seed is incredibly easy. The first year it will only grow to several feet high, but by the second or third year it should be topping 8-10′.

The seed is exceptionally cheap too. I’ve purchased from Roundstone seed several times, and find the quality and prices to be exceptional. Also, I have no affiliation with this company whatsoever, I just really like buying grass seed from them. Below is my short process on germinating Big Bluestem.

Purchase Seed

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Germinating Big Bluestem Seeds in Pots

In late early Spring, fill 4″ (10 cm) pots with moist potting soil to 1/2″ (12 mm) from the top.
Pack the potting soil so that it isn’t loose, but slightly firm.
Sprinkle 5-10 seeds on top, and press them firmly into the soil
Sprinkle a handful of potting soil on top of the pot, just dusting the seeds. I always make that I can still see some of the seeds, so that they are partially covered.
Keep moist until germination.

Also, you can winter sow Big Bluestem. Just repeat the process above, but set the seed tray outside but covered. Similar to the instruction in this video.

Below is a picture of a Little Bluestem seedling, however the seedlings are almost indistinguishable from Big Bluestem.

Direct Sowing Big Bluestem

You can also direct sow Big Bluestem in Autumn too. Just use a metal rake to disturb the top 1/2″ of soil, sprinkle seed in the area, and walk over it. The force from your shoes pressing the seed in the soil should be enough to maintain good soil/seed contact. Then, sprinkle a little bit of soil over the top to protect the seed from birds.

How to Save and Harvest Big Bluestem Seed

Once the seed head has turned brown and dried on the stalk for a week or two, you can collect them. Store them in a paper bag for a few weeks in a cool dry environment to allow the seed to dry completely. After this the seed can be stored for about six months and still be mostly viable.

Garden Uses

This plant may not be sold as an ornamental, but it should be. The blue green color is gorgeous during the Spring. And the late Summer bloom is very pretty too. As stated in the intro, when this plant sways in the breeze it is almost hypnotizing.

Big Bluestem in June, at the base of our Bee Hotel

Big Bluestem micro-prairie Andropogon gerardii — Big Bluestem in August. Where did our Bee Hotel go?

So, you can use this plant as a border, in a wildflower garden, or as an individual accent in a flowerbed. Just make sure you give it some room per our reference table (bottom of this article) in a flowerbed. We have several specimens in our backyard micro-prairie. These grasses help provide support for other species that can droop over under their own weight. You can learn how to make your own small prairie by clicking below. It really is a great way to bring on the wildlife!

How To Make Micro Prairie

Fauna

This plant is host to many insects, and provides forage for other insects. At least 12 different grass hoppers and many different skipper moths feed on the foliage. A partial list of Skippers caterpillars that feed on the foliage is below.

Byssus Skipper
Cobweb Skipper
Dakota Skipper
Delaware Skipper
Dusted Skipper
Ottoe Skipper

Additionally, Big Bluestem seeds are eaten by birds (particularly smaller songbirds). Furthermore the grass can provide cover to small mammals and other birds. This is really a great plant to grow if you want to attract wildlife.

Pests and diseases

None.

Big Bluestem Grass Reference Table
Common Name	Big Bluestem
Scientific name	Andropogon gerardii
Bloom Time	Late Summer / Fall
Bloom Duration	4 weeks
Color	Red/Purple
Bloom Size	Spiklets arrayed along the stem raceme
Characteristics	Multiple stems at the termination of each stalk
Height	~ 6-10’ (~ 2-3 m)
Spacing/Spread	2-3’ (60-90 cm)
Light Requirements	Full Sun / Partial Shade
Soil Types	Clay, Loam, sand
Moisture	Moist to dry
Maintenance	None. Cut back in Spring after insects have emerged
Typical Use	Meadow, prairie, roadside, erosion control
Fauna Associations	Caterpillars and other insects feed on foliage
Larval Host	Zabulon Skipper, Crossline Skipper, Homomok Skipper, Little Glassywing, Wood Nymph
Sowing Depth	0-1/8” (0-3 mm)
Stratification	60 days cold stratification. Or direct sow in Autumn/Winter
Native Range	USDA Zones 3-10
Notes	Growitbuildit.com