sourwood
Oxydendrum arboreum · Ericaceae
sourwood (Oxydendrum arboreum) is a perennial tree in the Ericaceae family. It is native to North America. USDA records it as hardy in zone 5 and warmer, down to about -13°F.
At a glance
| Type | tree Derived |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 35 ft USDA |
| Light | shade USDA |
| Water need | low USDA |
| Growth rate | slow USDA |
| Soil pH | 4–6.5 USDA |
| Bloom | June USDA |
| Flower color | White USDA |
| Hardiness zones | 5 and warmer USDA |
| Guild layer | understory 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 tolerates full shade. USDA rates it as having low water needs once established. Its drought tolerance is rated medium. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 4 to 6.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 5.
Size and growth
At maturity it reaches about 35 ft, making it a substantial woody plant. It grows slowly.
Bloom period
USDA records a bloom period of June. Flowers are white.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, coarse in texture. Its flowers are conspicuous. It carries conspicuous autumn colour. 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 30 to 40 inches of annual precipitation. It needs at least 150 frost-free days to finish its season. It roots to at least 30 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
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
Browsing animals find it moderately palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated low, and it can resprout after damage. Its growth form is recorded as single stem.
Role in a guild
Understory. In a layered planting this is the layer beneath the canopy, tall enough to hold structure but shaded from above. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Similar role and hardiness
- halberdleaf rosemallow Hibiscus laevis
- crimsoneyed rosemallow Hibiscus moscheutos
- pomegranate Punica granatum
- blackjack oak Quercus marilandica
- great laurel Rhododendron maximum
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol OXAR, 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, browse palatability, 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, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer, Type.
Read our full data sources and methodology.
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