Switchgrass Panicum virgatum
Switchgrass (Panicum virgatum) is a deciduous perennial grass in the Poaceae family, native to Prairies and open woodland of central and eastern North America. It grows 1.2–2 m (3.9–6.6 ft) tall and 60 cm–1 m (24 in–3.3 ft) wide, wants full sun and low water, and is hardy to about -34 °C (-29 °F). Space plants about 90 cm (35 in) apart.
Plan Switchgrass in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Switchgrass at a glance
| Type | Perennial grass, deciduous |
|---|---|
| Family | Poaceae |
| Mature height | 1.2–2 m (3.9–6.6 ft) |
| Mature spread | 60 cm–1 m (24 in–3.3 ft) |
| Spacing | 90 cm (35 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance moderate |
| Soil pH | 5.5–7.5 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | from about July for 6–10 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | High |
| Pollinator value | Low |
| Edible | Not grown as food |
| Native to | Prairies and open woodland of central and eastern North America |
| Common in gardens of | 🇺🇸 United States |
Is Switchgrass toxic?
- People: not known to be toxic
- Cats: not well documented
- Dogs: not well documented
- Parts: leaves (grazing)
Contains steroidal saponins that cause photosensitisation in grazing livestock; no clear pet data.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Switchgrass
No well-documented helpful pairing. Group it with plants that like full sun and low water.
See Switchgrass in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Longwood Gardens (10 plants)
- Denver Botanic Gardens (8 plants)
- New York Botanical Garden (6 plants)
- Riverside botanical garden (11 plants)
Questions about Switchgrass
- How far apart should I plant Switchgrass?
- About 90 cm (35 in) apart, centre to centre. A mature plant spreads 60 cm–1 m (24 in–3.3 ft).
- Does Switchgrass need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Switchgrass need?
- Low water. Drought tolerance is high and waterlogging tolerance moderate.
- How cold-hardy is Switchgrass?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- When does Switchgrass flower?
- From about July for 6–10 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Switchgrass poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people not known to be toxic. Contains steroidal saponins that cause photosensitisation in grazing livestock; no clear pet data.
- What grows well with Switchgrass?
- There is no well-documented companion pairing for Switchgrass. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- USDA PLANTS Database, USDA NRCS
- Extension Gardener Plant Toolbox, NC State Extension
- GRIN-Global Taxonomy, USDA ARS
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Fountain grass Pennisetum alopecuroides
- Sweet corn Zea mays var. saccharata
- Lemongrass Cymbopogon citratus
- Clumping bamboo Fargesia murielae
- Maiden grass (miscanthus) Miscanthus sinensis
- Golden bamboo Phyllostachys aurea
- Little bluestem Schizachyrium scoparium
- Blue fescue Festuca glauca