North America Native Plant

Japanese Bittercress

Botanical name: Cardamine regeliana

USDA symbol: CARE6

Life cycle: annual

Habit: forb

Native status: Native to Alaska  

Synonyms: Cardamine scutata Thunb. (CASC17)   

Japanese Bittercress: Alaska’s Delicate Arctic Native If you’re an Alaska gardener looking to embrace truly local flora, or a plant enthusiast fascinated by arctic species, Japanese bittercress (Cardamine regeliana) might just capture your imagination. This delicate annual forb represents one of Alaska’s unique botanical treasures, though it’s definitely not your ...

Japanese Bittercress: Alaska’s Delicate Arctic Native

If you’re an Alaska gardener looking to embrace truly local flora, or a plant enthusiast fascinated by arctic species, Japanese bittercress (Cardamine regeliana) might just capture your imagination. This delicate annual forb represents one of Alaska’s unique botanical treasures, though it’s definitely not your typical garden center find.

What Makes Japanese Bittercress Special?

Cardamine regeliana belongs to the mustard family and showcases the classic characteristics that make this plant group so recognizable. As an annual forb, it completes its entire life cycle in one growing season, producing small white flowers that are typical of the Cardamine genus. The plant lacks significant woody tissue, instead focusing its energy on rapid growth and reproduction during Alaska’s brief growing season.

This species is also known by the synonym Cardamine scutata, though Japanese bittercress remains the most commonly used name.

Where Does It Call Home?

Japanese bittercress is exclusively native to Alaska, making it a true regional specialty. You won’t find this little beauty growing wild anywhere else in North America, which makes it particularly special for Alaska gardeners who want to showcase their state’s unique botanical heritage.

Should You Grow Japanese Bittercress?

Here’s where things get interesting – and a bit challenging. While this native Alaskan plant has undeniable appeal for local gardeners, it comes with some important considerations:

For Alaska Gardeners:

  • Supporting native biodiversity in your landscape
  • Creating habitat for local wildlife and pollinators
  • Showcasing Alaska’s unique botanical heritage
  • Contributing to conservation efforts for regional species

For Gardeners Outside Alaska:

If you live outside Alaska, Japanese bittercress likely isn’t the right choice for your garden. Arctic and subarctic plants typically require very specific conditions that are difficult to replicate in warmer climates. Instead, consider exploring native Cardamine species from your own region – there are many beautiful bittercress relatives that might be perfect for your local conditions.

Growing Conditions and Care

As an arctic native, Japanese bittercress has evolved for Alaska’s unique climate conditions. While specific cultivation information is limited due to its specialized habitat requirements, we can make some educated assumptions based on its native environment:

  • Likely thrives in cool, moist conditions
  • Probably requires excellent drainage despite enjoying moisture
  • May need a cold stratification period for seed germination
  • Best suited for USDA hardiness zones 1-4

Wildlife and Pollinator Benefits

Like many members of the mustard family, Japanese bittercress likely provides valuable resources for Alaska’s native pollinators. The small white flowers typical of Cardamine species are usually rich in nectar and can support various small pollinators during Alaska’s brief but intensive growing season.

The Bottom Line

Japanese bittercress represents the fascinating world of highly specialized regional native plants. For Alaska gardeners interested in native landscaping, this species offers a unique opportunity to support local ecosystems and showcase botanical heritage. However, its very specific requirements mean it’s not suitable for gardeners in warmer climates.

If you’re outside Alaska but inspired by the idea of growing native bittercress species, research what Cardamine species are native to your area. You might discover equally fascinating local treasures that are much better suited to your growing conditions and will provide similar ecological benefits for your regional wildlife.

Remember, the best native garden is one that celebrates and supports your local ecosystem – and that means choosing plants that truly belong in your specific corner of the world.

Japanese Bittercress

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

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Cardamine L. - bittercress

Species

Cardamine regeliana Miq. - Japanese bittercress

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