Switchgrass 'Cloud Nine'
Panicum virgatum 'Cloud Nine' · Poaceae
The giant switchgrass: blue-green leaves and a huge, billowing cloud of golden flowers well above head height by early autumn.
- Size
- 7 ft tall, 3½ ft wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Early August to early October
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around switchgrass 'Cloud Nine'
The planner designed this bed around switchgrass 'Cloud Nine' 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 'Cloud Nine' stands where it does.
The plants
- 1 Switchgrass 'Cloud Nine' × 1, pink
- 2 Bloody cranesbill 'Max Frei' × 7, pink
- 3 Robin's plantain 'Lynnhaven Carpet' × 8, lavender
- 4 False sunflower 'Summer Sun' × 3, yellow
- 5 Slender mountain mint × 5, white
- 6 Spurge 'Chameleon' × 3, purple leaves
- 7 Allium 'Gladiator' × 1, purple
Why this plant
- The bed's only structure. Shrubs and grasses keep their shape when the perennials die down, and it is the only one here.
- The only airy sprays. The others are open bowls, daisies, dense clusters and others. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 7 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 allium 'Gladiator' (4 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for 9 weeks. From early August to early October.
- Closes the season. For its last four weeks 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: 26 of the 26 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. Low plants run along 99% of the front edge: bloody cranesbill 'Max Frei' and Robin's plantain 'Lynnhaven Carpet'. Cool colours (pink, lavender and purple) with yellow as the warm note, and white to calm things between them.
The planner's own design check: 9 Excellent, 7 Good, 1 Needs revision. Its weakest point is height and scale: Heights average about 8 in at the front, 20 in in the middle and 3½ ft at the back. Along the back row the heights step up and down, between 2½ ft and 7 ft, and no two neighbours are the same height. 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 'Cloud Nine' goes in a border
At 7 ft it belongs at the back of a bed. In the planner's ten height classes it is super tall (over 6½ ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
The native alternative to tall maiden grass. It gives height and a great, airy cloud of seed, and it stands through winter in all but the heaviest snow.
- A tall native specimen grass
- Screening
- The back of a large border
What to plant with switchgrass 'Cloud Nine'
Plants recorded as good partners for it, and what each pairing does:
- Joe Pye weed 'Gateway': in flower together for six weeks, from early August; bold leaves against its fine ones.
- New York ironweed: in flower together for seven weeks, from early August.
- Sunflower 'Lemon Queen': in flower together for eight weeks, from early August.
Questions about switchgrass 'Cloud Nine'
Does switchgrass 'Cloud Nine' need sun or shade?
Switchgrass 'Cloud Nine' 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 'Cloud Nine' 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 'Cloud Nine' flower in my zone?
In zone 5 it flowers early August to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Mid August to early October |
|---|---|
| Zone 5 | Early August to early October |
| Zone 6 | Early August to early October |
| Zone 7 | Early August to early October |
| Zone 8 | Early August to early October |
| Zone 9 | Late July 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 switchgrass 'Cloud Nine' be planted?
3 ft (90 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3½ ft (100 cm), so a group knits into one patch.
It grows 7 ft (210 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many switchgrass 'Cloud Nine' plants do I need?
At 3 ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 4 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is switchgrass 'Cloud Nine' 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 'Cloud Nine'?
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 'Cloud Nine'?
Switchgrass 'Cloud Nine' is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:
- Swamp sunflower: from late September to late October, 6½ ft tall.
- Tatarian aster 'Jindai': from early October to early November, 4 ft tall, to stand in front of it and cover its fading stems.
- 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 switchgrass 'Cloud Nine' look like in winter?
Switchgrass 'Cloud Nine' 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 'Cloud Nine' good for bees and butterflies?
Switchgrass 'Cloud Nine' 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 'Cheyenne Sky' Panicum virgatum 'Cheyenne Sky'
- 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
- Tall perennials and grasses for the back of a border
- 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
- 7 ft (210 cm) tall, 3½ ft (100 cm) wide
- Plant
- 3 ft (90 cm) apart
- Height class
- Super tall (over 6½ ft)
- Place in the bed
- Back, or further forward: it is airy enough to see through
- Flowers
- Early August to early October; airy sprays; pink
- 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
- 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. 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.