North America Native Plant

Stiff Willowherb

Botanical name: Epilobium rigidum

USDA symbol: EPRI

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Epilobium rigidum Hausskn. var. canescens Trel. (EPRIC)   

Stiff Willowherb: A Charming Native Wildflower for Western Gardens Meet stiff willowherb (Epilobium rigidum), a delightful native perennial that’s been quietly beautifying the landscapes of California and Oregon for centuries. This unassuming wildflower might not have the flashiest name, but don’t let that fool you – it’s a garden gem ...

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 ⚘

Stiff Willowherb: A Charming Native Wildflower for Western Gardens

Meet stiff willowherb (Epilobium rigidum), a delightful native perennial that’s been quietly beautifying the landscapes of California and Oregon for centuries. This unassuming wildflower might not have the flashiest name, but don’t let that fool you – it’s a garden gem that deserves serious consideration for your native plant landscape.

What Makes Stiff Willowherb Special?

Stiff willowherb is a true native of the western United States, naturally occurring in California and Oregon. As a perennial forb (that’s garden-speak for a non-woody flowering plant), it comes back year after year, establishing itself as a reliable presence in your garden without the drama of annual replanting.

This charming wildflower produces delicate pink to purple blooms that add a soft, naturalistic touch to any planting scheme. Its narrow leaves and modest stature give it an understated elegance that works beautifully in both formal native gardens and wild, naturalized spaces.

Why Consider Planting Stiff Willowherb?

There are several compelling reasons to welcome this native beauty into your garden:

  • Pollinator magnet: The flowers attract bees, butterflies, and other beneficial insects, supporting local ecosystem health
  • Low maintenance: Once established, it’s remarkably drought tolerant and requires minimal care
  • Native credentials: Supporting local ecosystems by choosing plants that evolved in your area
  • Versatile design element: Works well in rock gardens, wildflower meadows, and naturalized landscapes

A Word About Conservation

Before we dive into growing tips, there’s something important to know: stiff willowherb has a conservation status that suggests it may face some population pressures in the wild. This doesn’t mean you shouldn’t grow it – quite the opposite! Cultivating native plants in our gardens can actually help preserve them for future generations. However, it does mean you should be thoughtful about sourcing your plants from reputable nurseries that propagate their stock rather than wild-collecting.

Growing Stiff Willowherb Successfully

The good news is that stiff willowherb is relatively easy to grow if you can provide the right conditions. Here’s what this western native needs to thrive:

Ideal Growing Conditions

  • Sunlight: Full sun to partial shade (morning sun with afternoon shade works well)
  • Soil: Well-draining soil is essential – this plant doesn’t like wet feet
  • Water: Drought tolerant once established, but benefits from occasional deep watering during extended dry periods
  • Climate: Best suited for USDA hardiness zones 7-10, matching its native California and Oregon range

Planting and Care Tips

Getting started with stiff willowherb is straightforward:

  • Plant in spring after the last frost date in your area
  • Space plants appropriately based on mature size (check with your nursery for specific spacing recommendations)
  • Water regularly during the first growing season to help establish roots
  • Once established, reduce watering frequency – this plant actually prefers drier conditions
  • Deadhead spent blooms if you want to prevent self-seeding, or leave them for natural propagation
  • Minimal fertilization needed – native plants are adapted to local soil conditions

Perfect Garden Companions

Stiff willowherb plays well with other California and Oregon natives. Consider pairing it with other drought-tolerant perennials and native grasses to create a cohesive, water-wise landscape that supports local wildlife year-round.

The Bottom Line

If you’re gardening in California or Oregon and looking to support local ecosystems while creating beautiful, low-maintenance landscapes, stiff willowherb deserves a spot on your plant list. Its combination of native authenticity, pollinator appeal, and easy-going nature makes it a winner for gardeners who want to make a positive environmental impact without sacrificing beauty.

Just remember to source your plants responsibly, and you’ll be well on your way to enjoying this charming western native for years to come.

Stiff Willowherb

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 rigidum Hausskn. - stiff willowherb

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