Switchgrass 'Cheyenne Sky'
Panicum virgatum 'Cheyenne Sky' · Poaceae
A compact, vase-shaped switchgrass whose blue-green leaves begin to turn wine red in early summer, with purple flower heads to match.
- Size
- 3 ft tall, 18 in wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Late July to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around switchgrass 'Cheyenne Sky'
The planner designed this bed around switchgrass 'Cheyenne Sky' 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 switchgrass 'Cheyenne Sky' stands where it does.
The plants
- 1 Switchgrass 'Cheyenne Sky' × 3, purple
- 2 Common thyme × 4, lavender
- 3 Creeping phlox 'Emerald Blue' × 5, blue
- 4 Brown-eyed Susan × 8, yellow
- 5 Dwarf English boxwood × 1, dark green leaves
- 6 Salvia 'May Night' × 3, purple
- 7 Schubert's allium × 3, pink
Why this plant
- The only airy sprays. The others are dense clusters, open bowls, daisies and others. Shape reads at a distance, where colours blur.
- Part of the bed's structure. Shrubs and grasses keep their shape when the perennials die down. So does dwarf English boxwood.
Why here
- Anchors a back corner. At 3 ft it is one of the taller plants 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 brown-eyed Susan (4 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for 9 weeks. From late July to mid September.
- In company. With brown-eyed Susan in late July: 2 kinds at once.
- Stands through winter. Left uncut, it holds its shape until March, when the perennials have gone.
Planned as a contemporary bed: 22 of the 22 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. The back corners are held by switchgrass 'Cheyenne Sky' and brown-eyed Susan, the tallest plants on the plan. The front edge is finished with common thyme and creeping phlox 'Emerald Blue'.
The planner's own design check: 12 Excellent, 5 Good. 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 switchgrass 'Cheyenne Sky' goes in a border
At 3 ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
A dwarf red switchgrass, half the height of 'Shenandoah' and red a month earlier. It is hardy and tidy, and good in large pots.
- Red foliage from midsummer
- Small gardens
- Containers
What to plant with switchgrass 'Cheyenne Sky'
Plants recorded as good partners for it, and what each pairing does:
- Black-eyed Susan: purple against yellow, opposite each other on the colour wheel, in flower together for nine weeks.
- Sedum 'Autumn Joy': in flower together for six weeks, from mid August; bold leaves against its fine ones.
- Purple coneflower: in flower together for seven weeks, from late July.
Questions about switchgrass 'Cheyenne Sky'
Does switchgrass 'Cheyenne Sky' need sun or shade?
Switchgrass 'Cheyenne Sky' 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 switchgrass 'Cheyenne Sky' 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 switchgrass 'Cheyenne Sky' flower in my zone?
In zone 5 it flowers late July to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Early August to mid September |
|---|---|
| Zone 5 | Late July to mid September |
| Zone 6 | Late July to mid September |
| Zone 7 | Mid July to mid September |
| Zone 8 | Mid July to mid September |
| Zone 9 | Mid July to mid September |
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 switchgrass 'Cheyenne Sky' be planted?
16 in (40 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 18 in (45 cm), so a group knits into one patch.
It grows 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many switchgrass 'Cheyenne Sky' plants do I need?
At 16 in apart, set out in staggered rows:
- 7 to fill 10 square feet (about 1 m²)
- 8 for a single row 10 ft (3 m) long
- 21 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used three in one group.
Is switchgrass 'Cheyenne Sky' 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 switchgrass 'Cheyenne Sky'?
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 switchgrass 'Cheyenne Sky'?
Switchgrass 'Cheyenne Sky' is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Montauk daisy: from mid September to late October, 3 ft tall.
- October daphne: from mid September to late October, 8 in tall, to stand in front of it and cover its fading stems.
What does switchgrass 'Cheyenne Sky' look like in winter?
Switchgrass 'Cheyenne Sky' 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 switchgrass 'Cheyenne Sky' good for bees and butterflies?
Switchgrass 'Cheyenne Sky' is visited by songbirds.
It is a host plant: the caterpillars of common wood-nymph feed on its leaves. A butterfly can only lay its eggs on its host plants, so these do more for it than any nectar flower.
It is native to the United States and Canada (this is a named variety of the native plant).
More Panicum
- Bitter switchgrass 'Dewey Blue' Panicum amarum 'Dewey Blue'
- Switchgrass 'Cloud Nine' Panicum virgatum 'Cloud Nine'
- Switchgrass 'Heavy Metal' Panicum virgatum 'Heavy Metal'
- Switchgrass 'Northwind' Panicum virgatum 'Northwind'
- Switchgrass 'Prairie Sky' Panicum virgatum 'Prairie Sky'
- Switchgrass 'Shenandoah' Panicum virgatum 'Shenandoah'
In these guides
- Plants for wet soil and rain gardens
- Salt-tolerant plants for roadsides and coasts
- 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
- Ornamental grasses under 3 feet
- Plants with purple and burgundy leaves
- Host plants for the common wood-nymph
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Grass
- Size
- 3 ft (90 cm) tall, 18 in (45 cm) wide
- Plant
- 16 in (40 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- Late July to mid September; airy sprays; purple, red
- Leaves
- Fine texture, herbaceous; blue-green, red
- 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
- North America
- Attracts
- Songbirds
- Host plant for
- Common wood-nymph
- Stands up to
- Deer, drought, salt, wet soil, black walnut, pollution, 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.