Ornamental · Poaceae
Big Bluestem
Andropogon gerardii
Set it in full sun and lean soil, and this towering native grass holds its form from summer deep into winter.
Full sun
Every 7–21 days
60–90 days
USDA 3–9
Overview
Big bluestem was the dominant grass of the old tallgrass prairie, the reason it carries the title King of the Prairie Grasses. As a warm-season native, it can put on 4 to 8 feet (122 to 244 cm) of growth in one season, raising blue-green stems that take on copper and red as autumn comes on. Each seed head divides into three fingers at its tip, and that signature form is why many gardeners know it as turkeyfoot.
Few plants are easier to grow, largely because it demands so little. Once its deep root system is in place it endures drought, it accepts clay, sand, or poor ground without complaint, and it wants no fertilizer whatsoever. Provide sun and sharp drainage and it essentially manages itself.
There is a wild side to it. Big bluestem self-seeds and spreads wherever the site favors it, and it grows large enough to engulf a small bed, so it performs best in meadows, broad borders, and naturalistic plantings with space to roam. Left uncut over winter, the bleached stems and seed heads sustain birds and keep their structure against the snow.
Care
The short version: full sun, lean and well-drained soil, and no fertilizer. Water it as it settles in, then hand it over to the rain, and shear the spent growth once a year in late winter.
Light
Big bluestem requires full sun, which means 6 or more hours of direct light daily. It will accept a little shade, but without strong light the stems develop weak tissue and lean over, so the more sun it receives, the more upright it stands.
Water
Provide regular water only while it is establishing. After that it is drought tolerant and lives off rainfall in average to dry soil, calling for irrigation only every 7 to 21 days during a genuine drought.
Soil
Set it in lean, well-drained ground, ranging from dry to medium. It handles poor, sandy, or clay soil readily across a pH of 5.0 to 7.5, but rich, moist soil drives soft, flop-prone growth, so leave out the heavy amendments.
Temperature
This is a wide-range species, hardy through severe cold and summer heat alike, withstanding temperatures from roughly -29°F to 104°F (-34°C to 40°C). It dies back to the ground each winter and sends up fresh growth in the warmth of late spring.
Humidity
Ordinary outdoor air suits it, so there is no humidity level to manage. Good airflow counts for more than any moisture reading, because open spacing dries the foliage and helps keep occasional leaf rust from taking hold.
Feeding
Do not feed it. Big bluestem is a native that thrives on poor soil, and the surplus nutrients from fertilizer only produce weak, leggy stems that topple.
Pruning
Shear the whole clump back to a few inches in late winter or early spring, before new growth begins. Leave it standing through the cold months, when the dried stems and seed heads hold their structure and support wildlife.
Repotting
Big bluestem seldom needs lifting. If an aging clump begins to die out in the center or weakens after many years, dig and divide it in spring to renew the planting.
Size & spacing
A mature plant reaches 4 to 8 feet (122 to 244 cm) tall on a base of 2 to 3 feet (61 to 91 cm). Allow it that full footprint so air can circulate and the clump can stand on its own without pressing against its neighbors.
When to plant
Big bluestem is driven by summer heat and goes dormant in the cold. Sow seed indoors in late winter after a cold-moist chill, transplant once frost has passed in spring, or broadcast seed dormant through fall and winter. The purplish turkey-foot heads emerge from late summer into fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring, 8-10 weeks before last frost (cold-moist stratify seed)
- Plant: Spring after last frost, or dormant-seed in fall/winter
- Harvest: Late summer to fall (purplish turkey-foot seed heads)
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
For a grass this durable, big bluestem brings only a brief list of problems, and most lead back to too much shade or too rich a site. The early signs show up on the stems and leaves, where the remedy is usually straightforward. Match what you observe below, then correct it before it defines the appearance of the whole clump.
Stems lean over and the crown splits apart at the center
When big bluestem sprawls, the cause is nearly always insufficient light or surplus fertility. Both push the plant to produce soft, water-rich tissue that grows taller than its stems can structurally support, so they buckle. Relocate it to full sun, withhold all fertilizer, and shear it low in late winter so the next flush emerges short-noded and rigid. For a permanent fix, plant an upright cultivar like 'Blackhawks'.
Fix:
- Site in full sun
- Stop fertilizing and avoid rich amendments
- Cut back hard in late winter so sturdy new growth emerges
- Choose an upright cultivar such as 'Blackhawks' if flopping persists
Volunteer seedlings appear and the base creeps past its bounds
Big bluestem self-seeds freely and expands outward on short rhizomes, doing both most vigorously where the site is sunny, fertile, and moist. To restrain it, sever and discard the seed heads before the grain matures, which removes next year's volunteers at the source. Dividing the clump in spring keeps the crown in check, and any unwanted seedlings pull or transplant easily while young.
Fix:
- Cut and remove seed heads before they mature to limit self-seeding
- Divide and reduce the clump in spring
- Pull or transplant volunteer seedlings
An oversized clump that overruns a small bed and its neighbors
By nature this is a tallgrass-prairie giant, reaching 4 to 8 feet (122 to 244 cm) on a 2 to 3 foot (61 to 91 cm) base, so it inevitably overshadows anything sited too near it. Plan it as a backdrop or living screen, or move it where its full stature has room to develop. If you want it to stay put, dividing the crown reduces its footprint.
Fix:
- Relocate to a larger space or use as a backdrop/screen
- Divide to reduce footprint
Orange, rust-colored bumps speckling the foliage
Those raised orange flecks are rust, a foliar fungus that appears occasionally but seldom causes lasting injury. Improve airflow through the planting, remove leaves that are heavily spotted, and cut the entire clump back in late winter, which clears the overwintering spores before they can reinfect the spring growth. Beyond rust, this grass has no serious pests worth mentioning.
Fix:
- Improve air circulation
- Remove and dispose of heavily affected foliage
- Cut back in late winter to remove overwintering inoculum
Toxicity
Big bluestem is safe across the board. It is a native prairie grass with no poisonous tissue, absent from every ASPCA toxic-plant list, and in fact valued as livestock forage. The one thing to keep an eye on is the pollen, which can provoke hay fever in people already sensitive to grasses.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Safe to keep nearby. A cat that chews on a few blades may bring them back up, as cats do with any grass, but the plant contains nothing toxic.
Dogs None
Nothing to worry about. The foliage carries no toxins, so a dog can investigate or graze it without any harm.
Horses None
Entirely safe. Horses graze big bluestem willingly, and it rates among the better native pasture grasses for them.
Rabbits None
Safe for rabbits to browse. It is an ordinary grass with no poisonous tissue.
Livestock None
Valued as feed rather than any hazard. Cattle, goats, and sheep all consume it, and it stands as top-quality grazing throughout the prairie.
Birds None
No threat to birds, which eat the seed and take cover in the standing clumps over winter.
People None
Safe to handle and to be around. The one caveat is the pollen, which can trigger hay fever in anyone already allergic to grasses.
Grass pollen can trigger seasonal hay-fever allergies in sensitive people, and pets that nibble grass may occasionally vomit, but the plant is not poisonous.
Varieties
Most garden big bluestem is selected either for fall color or for a sturdier, more upright habit. These are the named cultivars worth being familiar with.
Blackhawks
An upright, flop-resistant selection; the dark green spring foliage matures to nearly black by autumn, and it was named Perennial Plant of the Year for 2026.
Red October
Selected for autumn display, when its leaves shift to a brilliant red to red-purple.
Indian Warrior
Grown for the deep red-purple coloring it develops as fall sets in.
Dancing Wind
Notable for the red-tinged foliage it holds through the fall season.
Andropogon hallii (sand bluestem)
A near relative adapted to dry, sandy sites that closely resembles big bluestem in appearance.
Companions
Big bluestem pairs naturally with the other tallgrass-prairie plants it grew up alongside, grasses and sun-loving forbs that share its taste for full sun and well-drained ground.
Plant near
Switchgrass (Panicum virgatum): Companion warm-season prairie grass often planted together for forage and naturalistic plantings.
Indiangrass (Sorghastrum nutans): Co-dominant tallgrass-prairie grass with matching site needs for meadow and restoration plantings.
Purple coneflower (Echinacea purpurea): Full-sun prairie forb that pairs well with big bluestem in native borders and meadows.
How to propagate
Big bluestem can be raised from seed or split from an existing clump, and by either route it multiplies easily once you understand its timing.
SeedEasy
Spring sowing, or dormant fall/winter seeding; cold-moist stratify for best germination · Somewhat slow to establish (1-2 seasons), then vigorous
Seed is the usual starting point, either sown in spring or broadcast dormant across fall and winter; a cold-moist chill first breaks the seed's dormancy and triggers reliable germination. Seedlings emerge strongly, but the stand needs a season or two to root deeply before it hits full stride. From there it carries on by itself, self-seeding freely wherever the site agrees with it.
DivisionEasy
Spring as new growth begins · One growing season
For quick increase, or to cut down an oversized crown, lift and split an established plant right as spring growth resumes. Working at that point lets the divisions root and fill out within a single season.
Myths
Big bluestem and little bluestem are the same plant.
They belong to separate genera and are not the same grass. Big bluestem, Andropogon gerardii, reaches 4 to 8 feet (122 to 244 cm) and bears the three-pronged turkey-foot seed head that gives it its name. Little bluestem, Schizachyrium scoparium, sits in a different genus entirely and tops out at a modest 1 to 3 feet. The names echo each other, yet the plants are not interchangeable.