North America Native Plant

Yellowflower Tarweed

Botanical name: Holocarpha virgata virgata

USDA symbol: HOVIV

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Yellowflower Tarweed: A Late-Season Native Bloomer for California Gardens If you’re looking for a native California plant that keeps the party going when most wildflowers have called it quits, meet yellowflower tarweed (Holocarpha virgata virgata). This unassuming annual might not win any beauty contests, but it’s got charm where it ...

Yellowflower Tarweed: A Late-Season Native Bloomer for California Gardens

If you’re looking for a native California plant that keeps the party going when most wildflowers have called it quits, meet yellowflower tarweed (Holocarpha virgata virgata). This unassuming annual might not win any beauty contests, but it’s got charm where it counts – providing crucial late-season nectar when pollinators need it most.

What is Yellowflower Tarweed?

Yellowflower tarweed is a native California annual forb that belongs to the sunflower family. As a forb, it’s an herbaceous plant without woody stems, living its entire life cycle in a single growing season. Don’t let the name tarweed put you off – while some family members can be a bit sticky, this species offers more benefits than drawbacks in the garden.

Where Does It Grow Naturally?

This hardy little plant is endemic to California, meaning you won’t find it growing wild anywhere else in the world. It thrives in the state’s grasslands, open areas, and disturbed sites, making it perfectly adapted to California’s Mediterranean climate and challenging growing conditions.

Why Consider Yellowflower Tarweed for Your Garden?

While it may not be the showiest plant in your garden, yellowflower tarweed earns its keep in several important ways:

  • Pollinator magnet: Blooms from late summer into fall when few other flowers are available
  • Native ecosystem support: Provides food and habitat for local wildlife
  • Drought tolerance: Once established, requires minimal water
  • Self-sufficient: Self-seeds readily, creating natural colonies
  • Low maintenance: Thrives with minimal care once established

Garden Design and Landscape Role

Yellowflower tarweed works best in informal, naturalistic settings rather than formal flower beds. Consider it for:

  • Native wildflower meadows
  • Pollinator gardens
  • Drought-tolerant landscapes
  • Naturalized areas and edges
  • Wildlife habitat gardens

Its modest height and somewhat weedy appearance make it ideal for background plantings or mixed with other native annuals and perennials that can provide structure and visual interest.

Growing Conditions and Care

One of the best things about yellowflower tarweed is how easy it is to grow – after all, it’s adapted to California’s sometimes harsh conditions.

Sunlight: Prefers full sun but can tolerate some light shade

Soil: Not picky about soil type, but requires good drainage. Thrives in poor to moderately fertile soils

Water: Drought tolerant once established. Water occasionally during establishment, then reduce watering significantly

Climate: Hardy in USDA zones 8-10, perfect for California’s Mediterranean climate

Planting and Propagation Tips

Growing yellowflower tarweed from seed is straightforward:

  • When to plant: Direct seed in fall for spring germination
  • Seed preparation: No special treatment needed
  • Planting depth: Barely cover seeds with soil
  • Spacing: Allow 6-12 inches between plants
  • Germination: Seeds will germinate with winter rains

Once established, yellowflower tarweed typically self-seeds, so you may find new plants appearing in subsequent years without any effort on your part.

Potential Drawbacks to Consider

While yellowflower tarweed has many benefits, it’s worth noting a few considerations:

  • Can self-seed aggressively in ideal conditions
  • Has a somewhat weedy appearance that may not suit formal gardens
  • Annual nature means plants die back after setting seed

The Bottom Line

Yellowflower tarweed might not be the star of your garden, but it’s definitely a valuable supporting player. If you’re committed to supporting native wildlife and creating habitat, this humble annual deserves a spot in your landscape. Its late-season blooms provide crucial resources when pollinators need them most, and its low-maintenance nature makes it perfect for gardeners who want maximum ecological benefit with minimal effort.

Consider yellowflower tarweed as part of a diverse native plant community, where its practical benefits can shine alongside more showy companions. Your local pollinators will thank you, even if your neighbors might not immediately understand its charm!

Yellowflower 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

Holocarpha Greene - tarweed

Species

Holocarpha virgata (A. Gray) D.D. Keck - yellowflower tarweed

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