North America Native Plant

Largeflower Spike-primrose

Botanical name: Epilobium pallidum

USDA symbol: EPPA7

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Boisduvalia macrantha A. Heller (BOMA)  âš˜  Boisduvalia pallida Eastw. (BOPA3)   

Largeflower Spike-Primrose: A Charming Native Annual for Western Gardens Meet the largeflower spike-primrose (Epilobium pallidum), a delightful native annual that brings understated charm to western gardens. While it might not have the showstopping presence of some garden favorites, this little forb has plenty of personality and plays an important role ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Largeflower Spike-Primrose: A Charming Native Annual for Western Gardens

Meet the largeflower spike-primrose (Epilobium pallidum), a delightful native annual that brings understated charm to western gardens. While it might not have the showstopping presence of some garden favorites, this little forb has plenty of personality and plays an important role in supporting local ecosystems.

What is Largeflower Spike-Primrose?

Largeflower spike-primrose is an annual forb—basically a non-woody flowering plant that completes its entire life cycle in one growing season. Don’t let the spike-primrose name fool you; it’s not actually related to true primroses. Instead, it belongs to the evening primrose family and produces small, delicate flowers that add a subtle splash of color to natural landscapes.

As a native plant species, largeflower spike-primrose naturally occurs in the lower 48 states, specifically thriving in California, Idaho, and Oregon. Its native status makes it a valuable addition for gardeners looking to support local wildlife and create authentic regional landscapes.

Why Consider Growing Largeflower Spike-Primrose?

Here are some compelling reasons to give this native annual a spot in your garden:

  • Native heritage: Supporting local ecosystems by choosing plants that naturally belong in your region
  • Low maintenance: As an annual that’s adapted to local conditions, it typically requires minimal care once established
  • Pollinator support: The flowers attract small bees and other beneficial insects
  • Versatile placement: With its facultative wetland status, it can thrive in both moist and drier locations
  • Seasonal interest: Provides natural, ephemeral beauty that changes with the seasons

Garden Design and Landscape Use

Largeflower spike-primrose works beautifully in several garden settings:

  • Native plant gardens: Perfect for creating authentic regional plant communities
  • Naturalized areas: Excellent for meadow-style plantings and natural landscapes
  • Seasonal displays: Adds annual color and texture to perennial plantings
  • Rain gardens: Its facultative wetland status makes it suitable for areas with variable moisture

Growing Conditions and Care

The good news is that largeflower spike-primrose is relatively easy to grow when you match its preferences:

Preferred Conditions:

  • Sunlight: Full sun to partial shade
  • Soil: Moist to wet soils, though it can adapt to various moisture levels
  • Hardiness: Generally suitable for USDA zones 6-9 in its native range
  • Moisture: Appreciates consistent moisture but can tolerate some variation

Planting and Establishment Tips

Getting started with largeflower spike-primrose is straightforward:

  • Timing: Direct seed in fall or early spring for best results
  • Soil prep: Ensure good drainage while maintaining adequate moisture
  • Maintenance: Minimal care required once established—just let nature take its course
  • Propagation: Primarily grown from seed; may self-seed in favorable conditions

Conservation Considerations

With a conservation status of S3S4, largeflower spike-primrose isn’t considered critically rare, but it’s always good practice to source seeds or plants from reputable native plant nurseries. This ensures you’re getting authentic regional genetics and supporting responsible propagation practices.

Is This Plant Right for Your Garden?

Largeflower spike-primrose might be perfect for you if:

  • You’re located in California, Idaho, or Oregon
  • You want to support native ecosystems and pollinators
  • You enjoy naturalistic garden styles
  • You’re looking for low-maintenance annual options
  • You have areas with variable moisture conditions

However, if you’re looking for bold, showy flowers or live outside its native range, you might want to explore other options that are better suited to your specific location and design goals.

Largeflower spike-primrose may not be the flashiest plant in the garden, but it offers something special: the satisfaction of growing a truly native species that belongs in your landscape. Sometimes the most rewarding garden choices are the quiet ones that work behind the scenes to support the bigger picture of healthy, sustainable gardening.

Largeflower Spike-primrose

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Myrtales

Family

Onagraceae Juss. - Evening Primrose family

Genus

Epilobium L. - willowherb

Species

Epilobium pallidum (Eastw.) Hoch & P.H. Raven - largeflower spike-primrose

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA