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Switchgrass
Panicum virgatum
Switchgrass blooms from August through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Switchgrass
Plant it in full sun. It prefers low water. It is hardy in USDA zones 4–9. Expect it to reach about 5 ft tall and 2.5 ft wide at maturity, in roughly 3 years (not yet checked).
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Switchgrass
Plant Switchgrass in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 6, the middle of its hardy zones 4 to 9, spring means March to May and fall means August or September. Once settled, it blooms from August to October.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Switchgrass get?
5 fttall5 ft 7 inan adult2.5 ftwideSee Switchgrass in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Switchgrass
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Switchgrass about 2.5 ft apart, center to center, so each plant has room to reach its full width.
Add Switchgrass to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Switchgrass' height, spread, hardiness zones, sun and trait tags were checked against 11 published sources on July 30, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- NC State ExtensionPanicum virgatumheight, spread, hardiness zones, sun, years to mature size and trait tags
- Missouri Botanical GardenPanicum virgatumheight, spread, hardiness zones, sun and trait tags
- New Moon NurseryPanicum virgatumheight, hardiness zones, sun, years to mature size and trait tags
- University of Wisconsin HorticultureSwitch Grass, Panicum virgatumheight, hardiness zones, sun, years to mature size and trait tags
- highplainsgardening.comHigh Plains Gardening, Texas High Plains Region (Panicum virgatum)height, spread and sun
- Lady Bird Johnson Wildflower CenterPanicum virgatumheight, sun and trait tags
- prairienursery.comPrairie Nursery (Switchgrass, Panicum virgatum)height, hardiness zones and sun
- Missouri Department of ConservationSwitchgrassheight and trait tags
- Native Plant Trust (Go Botany)Go Botany, Native Plant Trust (Panicum virgatum)height and trait tags
- US Forest ServicePanicum virgatumheight and sun
- Clemson Home and Garden Information CenterOrnamental Grasses and Grass-like Plantssun
How the checking works, and what each standard covers, is on the verified plants page.
Comes in 3 varieties across 2 colors
Same plant, same care - pick the color you are growing.
Compare every variety in the Switchgrass group
Every figure is the variety's own page fact. Tap a name to open it.
| Variety | Color | Blooms | Hardiness | Sun | Size (H × W) |
|---|---|---|---|---|---|
| Heavy Metal | Blue | Aug–Oct | Zones 4–9 | Full sun | 5 ft × 2.5 ft |
| Northwind | Orange | Aug–Oct | Zones 4–9 | Full sun | 6 ft × 2.5 ft |
| Shenandoah | Red | Aug–Oct | Zones 4–9 | Full sun | 4 ft × 2 ft |
| Switchgrassthis page | Pink | Aug–Oct | Zones 4–9 | Full sun | 5 ft × 2.5 ft |
Good to know about Switchgrass
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Safety
Young, growing plants harm grazing sheep, goats and horses: steroidal saponins cause liver injury and photosensitization. Not a documented dog or cat poison. per ASPCA and Wyoming
Worth knowing
Flopping is its main flaw, and shade and rich soil both cause it. Full sun plus lean, poor ground is what keeps the clump upright. per Wisconsin
Cold hardiness varies by cultivar
Southeast sources rate it zone 5 to 9; northern ones to zone 3a, with cultivars to 4a. It depends on the ecotype, so match the cultivar to your zone. per NC State and Wisconsin
Best for winter interest
Its stiff stems and tan seed plumes stand upright all winter for structure, cover and bird seed. Cut the clump back in late winter, not fall. per Penn State
Feeds birds and butterflies
Not a nectar plant but high wildlife value: a larval host for skipper butterflies, and its seeds and standing winter stems feed and shelter songbirds and small mammals. per NC State
Built for tough sites
NC State rates it resistant to deer, drought, erosion and air pollution, and slightly salt tolerant, so it holds up on exposed or roadside ground. per NC State
Spreads slowly, stays clumping
It self-seeds modestly and creeps by short rhizomes but stays a clump, not a running invader. How much it sows varies by cultivar and site. per Missouri
What pairs well with Switchgrass
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Thyme
Shares full sun and low water; blooms in late spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
Creeping Phlox
Shares full sun and low water; blooms in mid spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
White Clover
Shares full sun and low to moderate water; blooms in late spring, before this one opens; low at 4 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
Bachelor's Button
Shares full sun and low water; blooms in late spring, before this one opens; both are strong pollinator plants, and they feed in different months; lower at 2.5 ft, for the front of the border.
Grape Hyacinth
Shares full sun and low water; blooms in early spring, before this one opens; low at 8 in, to carpet the ground beneath; both offer pollinator forage, in different months.
Lamb's Ear
Shares full sun and low water; blooms in early summer, before this one opens; both are strong pollinator plants, and they feed in different months; lower at 1.5 ft, for the front of the border.
Crocus
Shares full sun and low water; blooms in late winter, extending the bed's season; low at 4 in, to carpet the ground beneath; both offer pollinator forage, in different months.
California Poppy
Shares full sun and low water; opens in late spring and overlaps into this one's season; both are strong pollinator plants; lower at 12 in, for the front of the border.
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