Canadian waterweed
Elodea canadensis · Hydrocharitaceae
Canadian waterweed (Elodea canadensis) is a perennial herbaceous plant in the Hydrocharitaceae family. It is native to North America. USDA records it as hardy in zone 3 and warmer, down to about -33°F.
⚠ Invasive or noxious status. USDA lists this plant with an invasive or noxious weed status somewhere in its range. Check your state's noxious weed list before planting it — in some states it is illegal to sell or plant.
Both flags are quoted from USDA PLANTS, not inferred.
At a glance
| Type | forb-herb USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Light | full-sun USDA |
| Water need | high USDA |
| Growth rate | rapid USDA |
| Soil pH | 4.8–7.8 USDA |
| Bloom | June–August USDA |
| Flower color | White USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | herb-layer 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 4.8 to 7.8 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
It grows quickly.
Bloom period
USDA records a bloom period of June through August. Flowers are white.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is gray-green, medium in texture. Its flowers are not conspicuous — a plant for form and foliage. Its active growth period is spring. USDA rates its lifespan as long.
What the site needs to provide
USDA records it across sites receiving 12 to 60 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 160 frost-free days to finish its season. It roots to at least 0 inches. Fertility requirement: medium.
Propagating it
Propagate it from seed and sprigs. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It spreads vegetatively at a rapid rate.
Resilience and wildlife
Its growth form is recorded as multiple stem.
Role in a guild
Herb layer. In a layered planting this is the herbaceous middle — perennials and grasses that fill the space between ground cover and shrubs. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Similar role and hardiness
- common maidenhair Adiantum capillus-veneris
- winter bentgrass Agrostis hyemalis
- European water plantain Alisma plantago-aquatica
- showy milkweed Asclepias speciosa
- butterfly milkweed Asclepias tuberosa
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol ELCA7, 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, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Invasive status, Lifecycle, lifespan, Light, 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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