Switchgrass care — light, water, toxicity and hardiness
Switchgrass (Panicum virgatum) wants full sun and a drink about every 10 days once established. It is hardy in USDA zones 4 to 9. It is safe to have around pets.
| scientific name | Panicum virgatum |
|---|---|
| family | Poaceae |
| category | grass |
| plant type | perennial |
| light | full sun |
| water cadence days | 10 |
| mature height cm | 180 |
| min zone | 4 |
| max zone | 9 |
| frost tolerant | true |
| toxic to pets | false |
| toxic to humans | false |
| edible | false |
How often should I water Switchgrass?
Prairie native; upright; fall colour.
Who eats it
Palatable to browsing animals such as deer: medium. Palatable to grazing animals: high. Palatable to people: no.
What it needs
Its shade tolerance is high. Its moisture use is medium. Its drought tolerance is medium. It wants at least about 30 inches of rain a year. Above roughly 60 inches of annual rain it struggles. It tolerates soil down to pH 4.5. It tolerates soil up to pH 8.0. Its fertility requirement is medium. Adapted to coarse, sandy soils: yes. Adapted to medium, loamy soils: yes. Adapted to fine, clay soils: yes. Its tolerance of waterlogging is medium. It needs at least 90 frost-free days. Its salt tolerance is medium. Its tolerance of chalky soil is low. Its fire tolerance is high. Fire resistant: no. It has been recorded down to -43°F. It suppresses neighbours chemically: no.
How it grows
It grows as a rhizomatous form. Its growth rate is rapid. Its lifespan is long. It puts on most of its growth in summer. It spreads by seed at a slow rate. It spreads vegetatively at a slow rate. It resprouts after damage: no. Coppices: no. At maturity it reaches about 6.0 feet. Its roots go down at least 16 inches. Its shape is erect. It holds its leaves through winter: no.
What it looks like
It blooms in mid summer. The flowers are yellow. Conspicuous in flower: no. The foliage is green. The foliage texture is medium. In summer the canopy is dense in porosity. In winter it is porous in porosity. Fall colour: no. The fruit or seed is brown. Fruit begins in summer. Fruit finishes by fall. It fruits medium. The fruit persists on the plant: no. The fruit is conspicuous: no.
Growing more of it
Propagated by seed: yes. Propagated by cuttings: no. Propagated by container: no. Propagated by bare root: no. Propagated by bulb: no. Propagated by corm: no. Propagated by tubers: no. Cold stratification required: yes. Seedling vigour is medium. Commercial availability: routinely available.
Source: Drafted from US Cooperative Extension horticulture guidance; pending HUMAN-05 review (issue 280) · ASPCA Toxic and Non-Toxic Plant List · 2026-09-02