Northern sea oats (river oats) Chasmanthium latifolium
Northern sea oats (river oats) (Chasmanthium latifolium) is a deciduous perennial grass in the Poaceae family, native to River banks and woodland of the eastern and central United States. It grows 60 cm–1.2 m (24 in–3.9 ft) tall and 40–70 cm (16–28 in) wide, wants part sun to part shade and moderate water, and is hardy to about -30 °C (-22 °F). Space plants about 40 cm (16 in) apart.
Plan Northern sea oats (river oats) in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Northern sea oats (river oats) at a glance
| Type | Perennial grass, deciduous |
|---|---|
| Family | Poaceae |
| Mature height | 60 cm–1.2 m (24 in–3.9 ft) |
| Mature spread | 40–70 cm (16–28 in) |
| Spacing | 40 cm (16 in) centre to centre |
| Sun | Part sun to part shade, at least 3 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance moderate |
| Soil pH | 5–8 |
| Cold hardiness | About -30 °C (-22 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 36 °C (97 °F) |
| Flowering | from about July for 6–10 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | None |
| Edible | Not grown as food |
| Native to | River banks and woodland of the eastern and central United States |
| Common in gardens of | 🇺🇸 United States, 🇨🇦 Canada, 🇬🇧 United Kingdom, 🇩🇪 Germany |
Is Northern sea oats (river oats) toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Not poisonous.
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 Northern sea oats (river oats)
No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.
Questions about Northern sea oats (river oats)
- How far apart should I plant Northern sea oats (river oats)?
- About 40 cm (16 in) apart, centre to centre. A mature plant spreads 40–70 cm (16–28 in).
- Does Northern sea oats (river oats) need full sun?
- Part sun to part shade: at least 3 hours of direct sun a day.
- How much water does Northern sea oats (river oats) need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance moderate.
- How cold-hardy is Northern sea oats (river oats)?
- It tolerates about -30 °C (-22 °F) once established, roughly USDA zone 4.
- When does Northern sea oats (river oats) flower?
- From about July for 6–10 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Northern sea oats (river oats) poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Not poisonous.
- What grows well with Northern sea oats (river oats)?
- There is no well-documented companion pairing for Northern sea oats (river oats). Group it with plants that like the same sun (part sun to part shade) and water (moderate).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
Notes and assumptions
- Broad, bamboo-like leaves and drooping, flat seed spikelets like little fish that turn from green to bronze and rattle in the wind into winter. One of the few ornamental grasses for shade; self-seeds freely.
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
- Switchgrass Panicum virgatum
- Little bluestem Schizachyrium scoparium