North America Native Plant

Big Tarweed

Botanical name: Blepharizonia plumosa plumosa

USDA symbol: BLPLP

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Big Tarweed: A Late-Blooming Native Gem for California Gardens If you’re looking for a native California wildflower that brings late-season color and buzzing pollinator activity to your garden, big tarweed (Blepharizonia plumosa plumosa) might just be the unsung hero you’ve been searching for. This cheerful annual proves that native doesn’t ...

Rare plant alert!

Region: Conservation status by state

Status: S4T1: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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 ⚘

Big Tarweed: A Late-Blooming Native Gem for California Gardens

If you’re looking for a native California wildflower that brings late-season color and buzzing pollinator activity to your garden, big tarweed (Blepharizonia plumosa plumosa) might just be the unsung hero you’ve been searching for. This cheerful annual proves that native doesn’t have to mean boring – it just means perfectly suited to your local ecosystem.

What Makes Big Tarweed Special

Big tarweed is a true California native, found naturally in the Central Valley and surrounding foothills. As an annual plant, it completes its entire life cycle in one growing season, making it a dynamic addition to wildflower gardens and naturalized landscapes. The plant produces clusters of small, bright yellow composite flowers that create a sunny display when many other wildflowers are calling it quits for the season.

Where You’ll Find It Growing Wild

This native beauty is endemic to California, where it thrives in the state’s Mediterranean climate. You’ll find it naturally occurring throughout the Central Valley and adjacent foothill regions, perfectly adapted to the area’s hot, dry summers and mild, wet winters.

Why Your Garden (and Local Wildlife) Will Love It

Big tarweed shines as a late-season pollinator magnet. When many other flowers have finished blooming, this hardy annual steps up to provide crucial nectar and pollen for native bees, butterflies, and other beneficial insects. It’s like setting up a late-summer buffet for your garden’s hardest workers!

The plant works beautifully in:

  • Native plant gardens
  • Wildflower meadows
  • Restored grassland areas
  • Low-water landscape designs
  • Wildlife habitat gardens

Growing Big Tarweed Successfully

One of the best things about big tarweed is how low-maintenance it can be when you work with its natural preferences rather than against them.

Climate Requirements: Big tarweed thrives in USDA hardiness zones 8-10, making it perfect for California’s Mediterranean climate zones.

Sun and Soil: Give this sun-lover a spot with full sun exposure and well-draining soil. It’s quite tolerant of poor soils and can handle drought conditions once established – a true California native trait!

Planting Tips: Since it’s an annual, big tarweed is typically grown from seed. Direct sow seeds in fall or early spring, lightly covering them with soil. The seeds will germinate when conditions are right, often with the first good rains.

Care and Maintenance: Once established, big tarweed requires minimal care. It’s adapted to California’s natural rainfall patterns, so avoid overwatering, especially during summer months. Let the plant go to seed if you want it to self-sow for next year’s display.

A Word About Conservation

Big tarweed has a Global Conservation Status of S4T1, which indicates it may have some conservation concerns. If you’re interested in adding this plant to your garden, make sure to source seeds or plants from reputable native plant suppliers who use responsibly collected material. Never collect seeds or plants from wild populations.

Is Big Tarweed Right for Your Garden?

Big tarweed is an excellent choice for gardeners who want to support local ecosystems while enjoying a low-maintenance, drought-tolerant annual. It’s particularly valuable for those creating habitat gardens or working to restore native plant communities. The late-season blooms make it especially worthwhile for gardeners wanting to extend the pollinator season in their landscapes.

Keep in mind that as an annual, you’ll need to replant or allow self-seeding each year. But for many native plant enthusiasts, watching this cheerful wildflower return season after season is part of the joy of gardening with natives.

Consider big tarweed if you’re gardening in California and want to add authentic local character to your landscape while supporting the native bees and butterflies that call your region home. It’s proof that sometimes the most valuable garden plants are the ones that have been thriving in your neighborhood for thousands of years.

Big Tarweed

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

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Blepharizonia Greene - blepharizonia

Species

Blepharizonia plumosa (Kellogg) Greene - big tarweed

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