Indian grass
Sorghastrum nutans · Poaceae
Tall, blue-green leaves and, in early autumn, glossy, golden-bronze plumes with bright yellow anthers. One of the four great grasses of the tallgrass prairie.
- Size
- 6 ft tall, 24 in wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Late August to early October
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around Indian grass
The planner designed this bed around Indian grass when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why Indian grass stands where it does.
The plants
- 1 Indian grass × 3, tan
- 2 Stemless gentian × 30, blue
- 3 Carpathian bellflower × 5, white
- 4 Brown-eyed Susan × 3, yellow
- 5 Inkberry 'Gem Box' × 1, dark green leaves
- 6 Purple milkweed × 3, purple
- 7 Schubert's allium × 2, pink
- 8 Hyacinth × 7, blue
Why this plant
- The only plumes. The others are trumpets, bells, daisies and others. Shape reads at a distance, where colours blur.
- The only tan. Tan sits between stronger colours and calms them.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does inkberry 'Gem Box'.
Why here
- Anchors a back corner. At 6 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to inkberry 'Gem Box' (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one clump. A single spire is too slight to hold a place alone, so here the accent is a clump.
Why now
- In flower for 7 weeks. From late August to early October.
- Part of the bed's peak. With Carpathian bellflower and brown-eyed Susan in late August: 3 kinds at once. No week has more.
- Stands through winter. Left uncut, it holds its shape until March, when the perennials have gone.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 38% of the planted ground. Stemless gentian is the plant there is most of: 30 of the 54. Cool colours (blue, purple and pink) with yellow as the warm note, and tan and white to calm things between them.
The planner's own design check: 12 Excellent, 3 Good, 2 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where Indian grass goes in a border
At 6 ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft).
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
The showiest flower of the prairie grasses: the plumes shine like polished bronze in low sun. It stays upright best in lean soil.
- Prairie and meadow planting
- Tall autumn plumes
- Winter structure
What to plant with Indian grass
Plants recorded as good partners for it, and what each pairing does:
- Big bluestem: in flower together for six weeks, from late August.
- New England aster: in flower together for five weeks, from early September.
- Showy goldenrod: in flower together for six weeks, from late August.
Questions about Indian grass
Does Indian grass need sun or shade?
Indian grass grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.
What zones does Indian grass grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does Indian grass flower in my zone?
In zone 5 it flowers late August to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Late August to early October |
|---|---|
| Zone 5 | Late August to early October |
| Zone 6 | Late August to early October |
| Zone 7 | Mid August to early October |
| Zone 8 | Mid August to early October |
| Zone 9 | Early August to early October |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should Indian grass be planted?
24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.
It grows 6 ft (180 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many Indian grass plants do I need?
At 24 in apart, set out in staggered rows:
- 3 to fill 10 square feet (about 1 m²)
- 6 for a single row 10 ft (3 m) long
- 10 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used three in one group.
Is Indian grass poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat Indian grass?
Mostly not. NC State lists it as resistant to deer. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
What flowers after Indian grass?
Indian grass is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:
- Tatarian aster 'Jindai': from early October to early November, 4 ft tall, to stand in front of it and cover its fading stems.
- Swamp sunflower: from late September to late October, 6½ ft tall.
- Chrysanthemum 'Sheffield Pink': from late September to early November, 2½ ft tall, to stand in front of it and cover its fading stems.
What does Indian grass look like in winter?
Indian grass turns the colour of straw and, left uncut, stands through the winter, with seed for the birds. Cut it down in late winter, before the new shoots come up.
Is Indian grass good for bees and butterflies?
Indian grass is visited by butterflies and songbirds.
It is native to the United States.
More Sorghastrum
- Indian grass 'Sioux Blue' Sorghastrum nutans 'Sioux Blue'
In these guides
- Plants for wet soil and rain gardens
- Plants that grow near black walnut
- Plants for slopes and banks
- Pet-safe plants for a sunny border
- Plants for butterflies
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
- Plants that flower in fall
- Plants with purple and burgundy leaves
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Grass
- Size
- 6 ft (180 cm) tall, 24 in (60 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back
- Flowers
- Late August to early October; feathery plumes; tan
- Leaves
- Fine texture, herbaceous; blue-green, bronze
- Shape
- Upright, clumping
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun
- Soil
- Average, well-drained
- Water
- Low
- Feeding
- None needed
- Family
- Poaceae
- Comes from
- Native to Southeastern United States and Central America
- Attracts
- Butterflies, songbirds
- Stands up to
- Deer, drought, wet soil, black walnut, erosion
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.