Indian grass 'Sioux Blue'
Sorghastrum nutans 'Sioux Blue' · Poaceae
Strictly upright, with broad, metallic blue leaves and tall, golden-bronze plumes in early autumn. The whole plant turns orange-gold.
- Size
- 6 ft tall, 2½ ft wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Late August to mid October
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around Indian grass 'Sioux Blue'
The planner designed this bed around Indian grass 'Sioux Blue' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) contemporary bed in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why Indian grass 'Sioux Blue' stands where it does.
The plants
- 1 Indian grass 'Sioux Blue' × 3, tan
- 2 Bloody cranesbill × 4, pink
- 3 Winter heath × 5, white
- 4 Purple coneflower × 3, purple
- 5 Silver sage × 1, silver leaves
- 6 Italian bugloss 'Dropmore' × 3, blue
- 7 Red spider lily × 8, red
Why this plant
- The only plumes. The others are open bowls, bells, daisies and others. Shape reads at a distance, where colours blur.
- A classic partner for purple coneflower. Both are on this plan. A pairing gardeners have proved outranks a general rule.
- The only tan. Tan sits between stronger colours and calms them.
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 purple coneflower (3 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 8 weeks. From late August to mid October.
- Closes the season. In its last week nothing else on the plan is in flower.
- Stands through winter. Left uncut, it holds its shape until March, when the perennials have gone.
Planned as a contemporary bed: 25 of the 25 plants that stand in groups (100%) are set out in a pattern with their neighbours: a straight row, a triangle, or five like the five on a dice. Something is in flower for 34 weeks between late January and mid October, with a pause of 4 weeks from late April. Bloody cranesbill is planted in two places along the bed, which gives it rhythm.
The planner's own design check: 11 Excellent, 4 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 'Sioux Blue' 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 blue foliage and stiff habit set it apart from the wild grass, which can sprawl. A tall, narrow accent for the back of a prairie border.
- A tall blue vertical
- Prairie planting
- Autumn plumes and colour
What to plant with Indian grass 'Sioux Blue'
Plants recorded as good partners for it, and what each pairing does:
- New England aster: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for six weeks.
- Black-eyed Susan: in flower together for five weeks, from late August; low enough (24 in) to stand in front of it.
- Purple coneflower: purple against yellow, opposite each other on the colour wheel, if you choose those colours, in flower together for three weeks; low enough (3 ft) to stand in front of it.
Questions about Indian grass 'Sioux Blue'
Does Indian grass 'Sioux Blue' need sun or shade?
Indian grass 'Sioux Blue' 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 'Sioux Blue' 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 'Sioux Blue' flower in my zone?
In zone 5 it flowers late August to mid October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Late August to mid October |
|---|---|
| Zone 5 | Late August to mid October |
| Zone 6 | Late August to mid October |
| Zone 7 | Mid August to mid October |
| Zone 8 | Mid August to mid October |
| Zone 9 | Early August to mid 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 'Sioux Blue' be planted?
24 in (60 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 2½ ft (75 cm), so a group knits into one patch.
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 'Sioux Blue' 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 'Sioux Blue' 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 'Sioux Blue'?
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 'Sioux Blue'?
Indian grass 'Sioux Blue' is over by mid 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.
- Japanese onion 'Ozawa': from early October to early November, 10 in tall, to stand in front of it and cover its fading stems.
- Bodnant viburnum 'Dawn': from early November to late December, 10 ft tall.
What does Indian grass 'Sioux Blue' look like in winter?
Indian grass 'Sioux Blue' 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 'Sioux Blue' good for bees and butterflies?
Indian grass 'Sioux Blue' is visited by butterflies and songbirds.
It is native to the United States and Canada (this is a named variety of the native plant).
More Sorghastrum
- Indian grass Sorghastrum nutans
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
- Garden plants native to Canada
- Plants for butterflies
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
- Plants that flower in fall
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, 2½ ft (75 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 mid October; feathery plumes; tan, yellow
- Leaves
- Fine texture, herbaceous; blue-green
- 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 and VASCAN (plants of Canada). 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.