North America Native Plant

Scouler’s St. Johnswort

Botanical name: Hypericum scouleri scouleri

USDA symbol: HYSCS2

Life cycle: perennial

Habit: forb

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Hypericum formosum Kunth var. scouleri (Hook.) J.M. Coult. (HYFOS)  âš˜  Hypericum formosum Kunth ssp. scouleri (Hook.) C.L. Hitchc. (HYFOS2)   

Scouler’s St. Johnswort: A Bright Native Perennial for Western Gardens If you’re looking for a cheerful, low-maintenance native perennial that’ll light up your garden with sunny yellow blooms, meet Scouler’s St. Johnswort (Hypericum scouleri scouleri). This delightful wildflower might not have the flashiest name, but it’s got personality in spades ...

Scouler’s St. Johnswort: A Bright Native Perennial for Western Gardens

If you’re looking for a cheerful, low-maintenance native perennial that’ll light up your garden with sunny yellow blooms, meet Scouler’s St. Johnswort (Hypericum scouleri scouleri). This delightful wildflower might not have the flashiest name, but it’s got personality in spades and the kind of easy-going nature that makes gardeners smile.

What Makes Scouler’s St. Johnswort Special?

This native beauty belongs to the St. John’s wort family and grows as an herbaceous perennial forb – basically, it’s a non-woody plant that dies back in winter and returns each spring with renewed vigor. You might also see it listed under its botanical synonyms Hypericum formosum var. scouleri or Hypericum formosum ssp. scouleri in older references, but they’re all the same wonderful plant.

Where Does It Call Home?

Scouler’s St. Johnswort is a true western native, naturally found across a impressive range from Canada down through the western United States. You’ll find wild populations thriving in Alberta and British Columbia, and throughout the American West including Arizona, California, Idaho, Montana, New Mexico, Oregon, Washington, and Wyoming.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where this plant really shines – those bright yellow flowers aren’t just pretty to look at. They’re absolutely magnetic to pollinators! Bees, butterflies, and other beneficial insects can’t resist the cheerful blooms and prominent stamens that provide easy access to pollen and nectar. If you’re trying to create a pollinator-friendly garden, Scouler’s St. Johnswort definitely deserves a spot on your plant list.

The flowers typically appear from summer through early fall, giving you months of golden color when many other perennials are starting to wind down for the season.

Perfect Garden Situations

This adaptable native works beautifully in several garden styles:

  • Native plant gardens where you want authentic regional flora
  • Wildflower meadows and naturalized areas
  • Xeriscape gardens thanks to its drought tolerance
  • Mountain and high-elevation gardens
  • Slopes and areas where erosion control is needed

Growing Scouler’s St. Johnswort Successfully

One of the best things about this native is how uncomplicated it is to grow. Scouler’s St. Johnswort thrives in USDA hardiness zones 4-9, making it suitable for most temperate climates.

Light and Soil: Give it full sun to partial shade and well-draining soil. It’s not particularly fussy about soil type, but good drainage is key to preventing root rot.

Water Needs: Once established, this tough little perennial is quite drought tolerant – perfect for water-wise gardening. During its first season, provide regular water to help it get established, then you can back off.

Maintenance: Here’s the beauty of native plants – they’re naturally low maintenance! Deadhead spent flowers to encourage continued blooming throughout the season. Every 3-4 years, you might want to divide clumps to keep the plant vigorous and prevent overcrowding.

Planting Tips for Success

  • Plant in spring after the last frost date
  • Space plants 12-18 inches apart to allow for natural spreading
  • Water regularly the first year, then reduce once established
  • Mulch around plants to conserve moisture and suppress weeds
  • Allow some flowers to go to seed if you want the plant to self-sow

The Bottom Line

Scouler’s St. Johnswort is one of those reliable, cheerful natives that just makes sense in western gardens. It supports local wildlife, requires minimal care once established, and provides months of bright yellow blooms when you need them most. Whether you’re creating a full native plant garden or just want to add some authentic regional character to your landscape, this unassuming perennial delivers beauty and ecological benefits in equal measure.

Plus, there’s something satisfying about growing a plant that’s been thriving in your region for thousands of years – it’s like partnering with nature rather than fighting against it.

Scouler’s St. Johnswort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Theales

Family

Clusiaceae Lindl. - Mangosteen family

Genus

Hypericum L. - St. Johnswort

Species

Hypericum scouleri Hook. - Scouler's St. Johnswort

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