North America Native Plant

Sapphire Woollystar

Botanical name: Eriastrum sapphirinum dasyanthum

USDA symbol: ERSAD

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Sapphire Woollystar: A California Native Gem for Your Garden If you’re looking to add a touch of California’s wild beauty to your garden, meet the sapphire woollystar (Eriastrum sapphirinum dasyanthum). This charming little native annual might not be the showiest plant in your garden, but it brings authentic local character ...

Sapphire Woollystar: A California Native Gem for Your Garden

If you’re looking to add a touch of California’s wild beauty to your garden, meet the sapphire woollystar (Eriastrum sapphirinum dasyanthum). This charming little native annual might not be the showiest plant in your garden, but it brings authentic local character and valuable ecological benefits that make it worth considering for the right spot.

What Is Sapphire Woollystar?

Sapphire woollystar is a native California annual that belongs to the forb family—basically, it’s an herbaceous plant without woody stems. Think of it as nature’s way of painting delicate splashes of blue and purple across the landscape. As an annual, it completes its entire life cycle in one growing season, but don’t let that fool you into thinking it’s not worth planting. This little charmer has a knack for self-seeding when happy, potentially returning year after year in your garden.

Where Does It Call Home?

This native beauty is exclusive to California, making it a true Golden State original. It’s perfectly adapted to the state’s Mediterranean climate and unique growing conditions. When you plant sapphire woollystar, you’re essentially rolling out the red carpet for a plant that has spent thousands of years perfecting its survival skills in your local environment.

Why You Might Want to Grow Sapphire Woollystar

There are several compelling reasons to give this native annual a spot in your garden:

  • True California native: Supporting local ecosystems by growing plants that belong there
  • Drought tolerance: Once established, it thrives with minimal water—perfect for water-wise gardening
  • Pollinator magnet: Attracts native bees and butterflies with its nectar-rich flowers
  • Low maintenance: As a native, it’s naturally adapted to local conditions
  • Authentic wildflower appeal: Adds genuine wild beauty to naturalistic gardens

Garden Design Ideas

Sapphire woollystar shines in specific garden settings:

  • Native plant gardens: Perfect for creating authentic California landscapes
  • Wildflower meadows: Adds delicate texture and color to mixed wildflower plantings
  • Drought-tolerant landscapes: Ideal for xeriscaping projects
  • Naturalistic borders: Provides soft, informal edges to more structured plantings

Growing Conditions and Care

Like most California natives, sapphire woollystar has some preferences when it comes to growing conditions:

  • Sunlight: Thrives in full sun locations
  • Soil: Prefers well-draining soils (soggy conditions are not its friend)
  • Water: Drought-tolerant once established, but benefits from occasional deep watering during dry spells
  • Climate zones: Best suited for USDA hardiness zones 8-10

Planting and Care Tips

Growing sapphire woollystar successfully is refreshingly straightforward:

  • Timing: Plant seeds in fall or early spring to align with natural rainfall patterns
  • Soil prep: Ensure good drainage—amend heavy clay soils with coarse sand or gravel if needed
  • Watering: Water gently until seedlings establish, then reduce frequency
  • Maintenance: Minimal care required once established—just let it do its thing
  • Self-seeding: Allow some plants to go to seed if you want it to return next year

Potential Considerations

While sapphire woollystar has many benefits, consider these factors:

  • Annual nature: You’ll need to replant or rely on self-seeding each year
  • Size and impact: This is a delicate plant that won’t dominate your landscape
  • Regional specificity: Only suitable for California gardens

The Bottom Line

Sapphire woollystar might not be the star of your garden show, but it’s the kind of supporting actor that makes everything else look better. If you’re committed to growing native California plants, creating habitat for local pollinators, or simply want to try something authentically regional, this charming annual deserves consideration. Its low-maintenance nature and drought tolerance make it particularly appealing for gardeners looking to reduce water use while supporting local ecosystems.

Just remember to source your seeds or plants responsibly from reputable native plant suppliers, and you’ll be contributing to the preservation of California’s natural heritage right in your own backyard.

Sapphire Woollystar

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Eriastrum Wooton & Standl. - woollystar

Species

Eriastrum sapphirinum (Eastw.) H. Mason - sapphire woollystar

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