Prairie dropseed
Sporobolus heterolepis · Poaceae
A fountain of hair-fine, emerald leaves, topped in late summer by an airy haze of flowers that smell of coriander or popcorn. It turns gold and orange in autumn.
- Size
- 2½ ft tall, 2½ ft wide
- Zones
- 3 to 9
- Light
- Full sun
- Flowers
- Mid August to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around prairie dropseed
The planner designed this bed around prairie dropseed 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 715 that suit those conditions and its dry soil, and says below why prairie dropseed stands where it does.
The plants
- 1 Prairie dropseed × 3, tan
- 2 Cheddar pinks 'Tiny Rubies' × 5, pink
- 3 Rock cress × 14, white
- 4 False sunflower 'Summer Sun' × 3, yellow
- 5 Silver sage × 1, silver leaves
- 6 Betony 'Hummelo' × 3, purple
- 7 Tiger lily × 4, orange
- 8 Blue allium × 12, blue
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.
- Part of the matrix. The low fabric of grasses and groundcovers that the taller plants come up through.
- The only airy sprays. The others are open bowls, dense clusters, daisies and others. Shape reads at a distance, where colours blur.
Why here
- At the back. At 2½ ft it is seen over betony 'Hummelo' (20 in) in front of it, and has nothing behind it to hide.
- A step in the back row. Next to tiger lily (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 six weeks. From mid August to mid September.
- Closes the season. For its last two 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 naturalistic planting: low grasses and groundcovers, the matrix, make up 55% of the planted ground. The flowering is at its height in late June, with 4 kinds out together. Heights step up from about 10 in at the front to 3 ft at the back.
The planner's own design check: 11 Excellent, 6 Good.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where prairie dropseed goes in a border
At 2½ ft it belongs in the middle of a bed. In the planner's ten height classes it is medium (24 in to 2½ ft). It is airy enough to see through, so it can also come forward and veil what is behind it.
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
The most elegant native grass, and a long-lived one. Use it as the calm, repeated element between flowering perennials. It is slow, and takes three years to reach full size.
- A fine-textured matrix for prairie planting
- Edging a path
- Massing as groundcover
What to plant with prairie dropseed
Plants recorded as good partners for it, and what each pairing does:
- Purple coneflower: in flower together for four weeks, from mid August.
- Butterfly weed: flowers first, late June to early August, so the spot is never empty; happy in the same dry soil.
- Rattlesnake master: in flower together for two weeks, from mid August; bold leaves against its fine ones; tall enough (4 ft) to stand behind it.
Questions about prairie dropseed
Does prairie dropseed need sun or shade?
Prairie dropseed grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.
What zones does prairie dropseed grow in?
USDA zones 3 to 9. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does prairie dropseed flower in my zone?
In zone 5 it flowers mid August to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Late August to mid September |
|---|---|
| Zone 4 | Late August to mid September |
| Zone 5 | Mid August to mid September |
| Zone 6 | Mid August to mid September |
| Zone 7 | Early August to mid September |
| Zone 8 | Early August to mid September |
| Zone 9 | Early August 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 prairie dropseed 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 2½ ft (75 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many prairie dropseed 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 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 prairie dropseed 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 prairie dropseed?
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 prairie dropseed?
Prairie dropseed 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.
- 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 prairie dropseed look like in winter?
Prairie dropseed 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 prairie dropseed good for bees and butterflies?
Prairie dropseed is visited by songbirds.
It is native to the United States and Canada.
More Sporobolus
- Prairie dropseed 'Tara' Sporobolus heterolepis 'Tara'
In these guides
- Plants that grow near black walnut
- Plants for slopes and banks
- Plants you can walk on
- Pet-safe plants for a sunny border
- Garden plants native to Canada
- Plants that feed garden birds
- Ornamental grasses under 3 feet
- Plants that flower in fall
- Plants with purple and burgundy leaves
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Grass
- Size
- 2½ ft (75 cm) tall, 2½ ft (75 cm) wide
- Plant
- 24 in (60 cm) apart
- Height class
- Medium (24 in to 2½ ft)
- Place in the bed
- Middle, or further forward: it is airy enough to see through
- Flowers
- Mid August to mid September; airy sprays; tan
- Leaves
- Fine texture, herbaceous; green, bronze
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 3 to 9
- Light
- Full sun
- Soil
- Lean, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Poaceae
- Comes from
- Canada to U.S.A
- Attracts
- Songbirds
- Stands up to
- Deer, drought, black walnut, pollution, erosion, foot traffic
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.