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tufted evening primrose

Oenothera caespitosa · Onagraceae

tufted evening primrose (Oenothera caespitosa)
Photo: Stan Shebs · CC BY-SA · via Wikimedia Commons

tufted evening primrose (Oenothera caespitosa) is a perennial herbaceous plant in the Onagraceae 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

Typeforb-herb Derived
Lifecycleperennial USDA
Native statusnative USDA
Mature height0.5 ft USDA
Lightfull-sun USDA
Water needlow USDA
Growth raterapid USDA
Soil pH6.5–8 USDA
BloomMay–June USDA
Flower colorWhite USDA
Hardiness zones5 and warmer USDA
Guild layerground-cover Derived
Nursery availabilityContracting Only 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 low water needs once established. Its drought tolerance is rated high. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 6.5 to 8 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 5.

Size and growth

At maturity it reaches about 0.5 ft, making it a low, mat-forming plant. It grows quickly.

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 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 7 to 69 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 140 frost-free days to finish its season. It roots to at least 6 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

Propagating it

Propagate it from seed and container stock. 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 rapid 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 medium. 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.

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Tags

deciduousdrought-tolerantsalt-toleranthedgesandy-soilnativefull-sunfast-growingground-cover

Related plants

Others in Oenothera

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol OECA10, 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.

Read our full data sources and methodology.

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