North America Native Plant

Soft Western Rosinweed

Botanical name: Calycadenia mollis

USDA symbol: CAMO4

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Hemizonia mollis (A. Gray) A. Gray (HEMO7)   

Soft Western Rosinweed: A Hidden Gem for California Native Gardens If you’re looking to add some authentic California charm to your garden while supporting local wildlife, let me introduce you to a delightfully understated native annual: soft western rosinweed (Calycadenia mollis). This member of the sunflower family might not have ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Soft Western Rosinweed: A Hidden Gem for California Native Gardens

If you’re looking to add some authentic California charm to your garden while supporting local wildlife, let me introduce you to a delightfully understated native annual: soft western rosinweed (Calycadenia mollis). This member of the sunflower family might not have the flashiest name, but it packs a punch when it comes to supporting pollinators and adding late-season color to your landscape.

What is Soft Western Rosinweed?

Soft western rosinweed is a California native annual forb that belongs to the vast sunflower family. As an herbaceous plant, it lacks woody stems and completes its entire life cycle in one growing season. You might also encounter this plant under its former scientific name, Hemizonia mollis, if you’re browsing older gardening references.

This charming wildflower is truly a Golden State original, growing exclusively in California. You’ll find it naturally occurring throughout the Central Valley and surrounding foothills, where it has adapted beautifully to the region’s Mediterranean climate.

Why Grow Soft Western Rosinweed?

There are several compelling reasons to consider adding this native annual to your garden:

  • Pollinator magnet: The small, cheerful yellow flowers are incredibly attractive to native bees, butterflies, and other beneficial insects
  • Low maintenance: Once established, this drought-tolerant plant requires minimal care
  • Authentic California native: Support local ecosystems by growing plants that naturally belong in your region
  • Late-season interest: Blooms when many other wildflowers are fading, extending the season of interest
  • Self-seeding: Will naturalize in appropriate conditions, creating sustainable wildflower displays

Important Conservation Note

Before you start shopping for seeds, there’s something important to know: soft western rosinweed has a somewhat uncertain conservation status. While not critically endangered, it’s not as common as it once was. If you decide to grow this native beauty, please make sure to source your seeds from reputable native plant nurseries that collect responsibly and sustainably.

Garden Design and Landscape Use

Soft western rosinweed shines in several garden settings:

  • Native wildflower gardens: Perfect for recreating California’s natural grassland communities
  • Xeric landscapes: Ideal for water-wise gardens that celebrate drought-adapted plants
  • Pollinator gardens: An excellent addition to any space designed to support beneficial insects
  • Naturalized areas: Great for low-maintenance spaces where you want to encourage native plant communities

Growing Conditions and Care

Like many California natives, soft western rosinweed appreciates conditions that mimic its natural habitat:

  • Sunlight: Full sun is essential for best growth and flowering
  • Soil: Well-draining soils are crucial; this plant won’t tolerate soggy conditions
  • Water: Drought tolerant once established, though some supplemental water during dry spells can extend blooming
  • Climate zones: Best suited for USDA zones 8-10, matching California’s Mediterranean climate

Planting and Care Tips

Growing soft western rosinweed successfully is surprisingly straightforward:

  • Timing: Direct sow seeds in fall for spring germination, following nature’s schedule
  • Preparation: Lightly rake the soil surface but don’t bury seeds too deeply
  • Watering: Provide regular moisture until seedlings are established, then reduce watering
  • Maintenance: Minimal care required once plants are growing; deadheading can extend blooming period
  • Succession: Allow some plants to go to seed for next year’s display

The Bottom Line

Soft western rosinweed might not be the showiest plant in your garden, but it offers something increasingly valuable: authentic local character combined with genuine ecological benefits. For California gardeners looking to create landscapes that support native wildlife while requiring minimal resources, this modest annual deserves serious consideration. Just remember to source your seeds responsibly and enjoy watching the parade of pollinators that will surely follow!

Soft Western Rosinweed

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

Calycadenia DC. - western rosinweed

Species

Calycadenia mollis A. Gray - soft western rosinweed

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