North America Native Plant

O’kennon’s Hawthorn

Botanical name: Crataegus okennonii

USDA symbol: CROK2

Life cycle: perennial

Habit: shrub

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

O’kennon’s Hawthorn: A Rare Northwestern Native Worth Knowing Meet O’kennon’s hawthorn (Crataegus okennonii), a little-known member of the beloved hawthorn family that calls the Pacific Northwest home. While you won’t find this shrub at your typical garden center, this rare native deserves a spot on every native plant enthusiast’s radar. ...

Rare plant alert!

Region: Conservation status by state

Status: S2S4: Status is uncertain but is somewhere between the following rankings: Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ 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 ⚘

O’kennon’s Hawthorn: A Rare Northwestern Native Worth Knowing

Meet O’kennon’s hawthorn (Crataegus okennonii), a little-known member of the beloved hawthorn family that calls the Pacific Northwest home. While you won’t find this shrub at your typical garden center, this rare native deserves a spot on every native plant enthusiast’s radar.

What Makes O’kennon’s Hawthorn Special?

O’kennon’s hawthorn is a perennial shrub that embodies the classic hawthorn form – a multi-stemmed woody plant that typically stays under 13 to 16 feet tall. Like other members of the Crataegus family, it develops several stems from near the ground, creating that distinctive shrubby appearance we associate with hawthorns.

Where You’ll Find This Northwestern Native

This hawthorn has a relatively limited range, naturally occurring across parts of the Pacific Northwest and northern Rocky Mountains. You can find it growing wild in British Columbia, Idaho, Montana, and Washington – a distribution that speaks to its preference for cooler, mountainous climates.

A Word About Rarity

Important conservation note: O’kennon’s hawthorn carries a Global Conservation Status of S2S4, indicating it may be rare or uncommon in parts of its range. If you’re interested in growing this species, it’s crucial to source plants only from reputable native plant nurseries that propagate from ethically collected seeds or cuttings. Never harvest from wild populations.

Why Consider This Hawthorn?

While specific details about O’kennon’s hawthorn’s garden performance are limited due to its rarity, hawthorns as a group offer several benefits to native gardens:

  • Native wildlife support (though specific benefits for this species aren’t well documented)
  • Adaptation to regional climate conditions
  • Potential for spring flowers and fall berries, typical of hawthorn species
  • Multi-season interest as a shrub

Growing Considerations

Due to the limited documentation available for this specific species, growing recommendations must be extrapolated from its native habitat and related hawthorn species. Given its natural range in British Columbia, Idaho, Montana, and Washington, O’kennon’s hawthorn likely prefers:

  • Cooler climates with distinct seasons
  • Well-draining soils
  • Full sun to partial shade conditions
  • USDA hardiness zones that correspond to its native range (likely zones 3-7)

The Challenge of Growing Rare Natives

Here’s the reality: O’kennon’s hawthorn isn’t your typical garden center find. Its rarity means that specific growing guides, propagation methods, and care instructions aren’t readily available. If you’re determined to grow this species, you’ll need patience and a willingness to experiment based on general hawthorn care principles.

Should You Plant O’kennon’s Hawthorn?

This comes down to your gardening goals and experience level. If you’re a dedicated native plant gardener with experience growing challenging species, and you can source plants responsibly, O’kennon’s hawthorn could be a unique addition to a native Northwestern garden. However, if you’re looking for reliable, well-documented native options, consider other Pacific Northwest hawthorns with better-known growing requirements.

The Bottom Line

O’kennon’s hawthorn represents both the excitement and challenge of working with rare native plants. While we celebrate the diversity it adds to our regional flora, its conservation status means we must approach cultivation thoughtfully. Whether you choose to seek out this rare hawthorn or opt for better-documented relatives, supporting native plants in our gardens helps preserve the botanical heritage of the Pacific Northwest.

Remember: when it comes to rare natives, conservation comes first. If you can’t source O’kennon’s hawthorn responsibly, there are many other wonderful native hawthorns and shrubs that can provide similar ecological benefits with less conservation concern.

O’kennon’s Hawthorn

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

Rosales

Family

Rosaceae Juss. - Rose family

Genus

Crataegus L. - hawthorn

Species

Crataegus okennonii Phipps - O'kennon's hawthorn

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