North America Native Plant

Coastal Tarweed

Botanical name: Deinandra corymbosa macrocephala

USDA symbol: DECOM

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Hemizonia corymbosa (DC.) Torr. & A. Gray ssp. macrocephala (Nutt.) D.D. Keck (HECOM)   

Coastal Tarweed: A Golden Gem for California Native Gardens If you’re looking to add a splash of sunny yellow to your California native garden while supporting local pollinators, coastal tarweed (Deinandra corymbosa macrocephala) might just be the perfect addition. This charming annual wildflower brings both beauty and ecological value to ...

Rare plant alert!

Region: Conservation status by state

Status: S3?T1T2: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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) ⚘ Subspecies or variety is 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) ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘

Coastal Tarweed: A Golden Gem for California Native Gardens

If you’re looking to add a splash of sunny yellow to your California native garden while supporting local pollinators, coastal tarweed (Deinandra corymbosa macrocephala) might just be the perfect addition. This charming annual wildflower brings both beauty and ecological value to drought-tolerant landscapes, though it comes with an important conservation consideration we’ll discuss.

What Makes Coastal Tarweed Special?

Coastal tarweed is a true California native, belonging to the sunflower family and previously known by the scientific name Hemizonia corymbosa ssp. macrocephala. As an annual forb (that’s botanist-speak for a non-woody herbaceous plant), it completes its entire life cycle in one growing season, making it a dynamic addition to ever-changing native plant communities.

This delightful wildflower produces clusters of small, bright yellow daisy-like flowers that seem to glow in the California sunshine. The aromatic foliage adds another sensory dimension to your garden, releasing a distinctive fragrance that’s particularly noticeable on warm days.

Where Does Coastal Tarweed Call Home?

Coastal tarweed is endemic to California, where it thrives in the state’s coastal scrub and chaparral habitats. You’ll find it naturally occurring along the coast, where it has adapted to the Mediterranean-style climate of dry summers and mild, wet winters.

Important Conservation Note

Before we dive into growing tips, there’s something crucial to know: coastal tarweed has a conservation status that suggests it may be rare or declining in some areas. This means if you want to grow this beautiful native, it’s essential to source seeds or plants only from reputable native plant nurseries that use responsibly collected material. Never collect seeds from wild populations, as this could harm already vulnerable plant communities.

Why Grow Coastal Tarweed?

There are several compelling reasons to include this native annual in your garden:

  • Pollinator magnet: The nectar-rich flowers attract native bees, butterflies, and other beneficial insects
  • Water-wise: Once established, it’s remarkably drought tolerant
  • Low maintenance: As an annual, it doesn’t require long-term care commitments
  • Authentic habitat: Helps recreate natural California plant communities
  • Self-seeding: Can naturalize in appropriate conditions, creating sustainable populations

Perfect Garden Settings

Coastal tarweed shines in several garden styles:

  • Native California plant gardens
  • Mediterranean-style drought-tolerant landscapes
  • Naturalized wildflower meadows
  • Pollinator gardens focused on native species
  • Coastal restoration projects

Growing Coastal Tarweed Successfully

Climate Zones: Best suited for USDA hardiness zones 9-11, which encompass coastal California’s mild climate.

Sun and Soil: Give coastal tarweed full sun and well-draining soil. It particularly loves sandy or rocky soils that mimic its natural coastal habitat. Heavy clay or waterlogged soils are definite no-nos.

Planting: The best approach is direct seeding in fall or early spring. Scatter seeds over prepared soil and lightly rake them in. Don’t bury them too deeply – these small seeds need light to germinate properly.

Watering: Water gently until seeds germinate and seedlings establish. Once plants are growing well, reduce watering significantly. Coastal tarweed is adapted to California’s dry summers and actually prefers less water once mature.

Maintenance: This is delightfully low-maintenance! Simply let the plants complete their natural cycle. If you want them to self-seed for next year, allow some flowers to go to seed before cleaning up the garden.

A Word of Caution and Encouragement

While coastal tarweed’s potential rarity means we need to be thoughtful about sourcing, it also makes growing it responsibly all the more meaningful. By cultivating this native species in our gardens, we’re creating habitat, supporting pollinators, and potentially helping preserve genetic diversity for future generations.

Just remember: always source from reputable native plant sellers, never collect from the wild, and consider sharing seeds with other native plant enthusiasts to help spread this golden treasure responsibly.

Ready to add some authentic California sunshine to your garden? Coastal tarweed might be small in stature, but it’s big on charm and ecological value – exactly what every native garden needs.

Coastal 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

Deinandra Greene - tarweed

Species

Deinandra corymbosa (DC.) B.G. Baldw. - coastal tarweed

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