American water plantain
Alisma subcordatum · Alismataceae
American water plantain (Alisma subcordatum) is a perennial herbaceous plant in the Alismataceae family. It is native to North America. USDA records it as hardy in zone 3 and warmer, down to about -33°F.
At a glance
| Type | forb-herb USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 0.5 ft USDA |
| Light | full-sun USDA |
| Water need | high USDA |
| Growth rate | moderate USDA |
| Soil pH | 5–7 USDA |
| Bloom | May–June USDA |
| Flower color | White USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | ground-cover Derived |
| Nursery availability | Routinely Available USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It needs full sun. USDA rates it as having needs consistently moist ground. Its drought tolerance is rated none — it needs reliable moisture. It tolerates saturated, poorly drained ground well (USDA rates its anaerobic tolerance high). It is recorded on soils from pH 5 to 7 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 0.5 ft, making it a low, mat-forming plant. It grows at a moderate rate.
Bloom period
USDA records a bloom period of May through June. Flowers are white.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, medium in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as moderate.
What the site needs to provide
USDA records it across sites receiving 35 to 60 inches of annual precipitation. It needs at least 90 frost-free days to finish its season. It roots to at least 8 inches. Fertility requirement: medium.
Propagating it
Propagate it from seed, bare root and sprigs. Seed needs cold stratification — a period of moist chilling — before it will germinate, so sow in autumn or chill it artificially before a spring sowing. Its seed spreads at a moderate rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Its fire tolerance is rated high. Its growth form is recorded as single crown.
Role in a guild
Ground cover. In a layered planting this is the lowest layer — it shades soil, holds moisture, and suppresses weeds. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Alisma
- narrowleaf water plantain Alisma gramineum
- European water plantain Alisma plantago-aquatica
Similar role and hardiness
- velvet bentgrass Agrostis canina
- kinnikinnick Arctostaphylos uva-ursi
- golden sedge Carex aurea
- white marsh marigold Caltha leptosepala
- European lily of the valley Convallaria majalis
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol ALSU, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, lifespan, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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