swamp cottonwood
Populus heterophylla · Salicaceae
swamp cottonwood (Populus heterophylla) is a perennial tree in the Salicaceae family. It is native to North America. USDA records it as hardy in zone 4 and warmer, down to about -23°F.
At a glance
| Type | tree USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 100 ft USDA |
| Light | full-sun USDA |
| Water need | high USDA |
| Growth rate | moderate USDA |
| Soil pH | 4.6–5.9 USDA |
| Bloom | April–May USDA |
| Flower color | White USDA |
| Hardiness zones | 4 and warmer USDA |
| Guild layer | canopy Derived |
| Nursery availability | No Known Source 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 low. It tolerates saturated, poorly drained ground well (USDA rates its anaerobic tolerance high). It is recorded on soils from pH 4.6 to 5.9 — acidic ground. Its cold limit is zone 4.
Size and growth
At maturity it reaches about 100 ft, making it a large tree that will dominate its site. It grows at a moderate rate.
Bloom period
USDA records a bloom period of April through May. Flowers are white.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, coarse in texture. Its flowers are not conspicuous — a plant for form and foliage. Its active growth period is spring and summer. USDA rates its lifespan as short, so plan on replacing or resowing it rather than treating it as permanent structure.
What the site needs to provide
USDA records it across sites receiving 35 to 60 inches of annual precipitation. It needs at least 180 frost-free days to finish its season. It roots to at least 24 inches. Fertility requirement: medium.
Propagating it
Propagate it from seed, bare root and container stock. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Its fire tolerance is rated medium, and it can resprout after damage. Its growth form is recorded as single stem.
Role in a guild
Canopy. In a layered planting this is the tallest layer of a planting — it sets the light budget everything beneath it lives on. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Populus
- white poplar Populus alba
- narrowleaf cottonwood Populus angustifolia
- balsam poplar Populus balsamifera
- black cottonwood Populus balsamifera
Similar role and hardiness
- Fraser fir Abies fraseri
- white alder Alnus rhombifolia
- red alder Alnus rubra
- incense cedar Calocedrus decurrens
- pecan Carya illinoinensis
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol POHE4, 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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