North America Native Plant

Showy Goldenbanner

Botanical name: Thermopsis robusta

USDA symbol: THRO4

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Showy Goldenbanner: A Rare California Native Worth Growing If you’re looking to add a splash of sunshine to your California native garden, meet the showy goldenbanner (Thermopsis robusta) – a perennial beauty that’s as rare as it is stunning. This golden-flowered native deserves a spot in more gardens, but there’s ...

Rare plant alert!

Region: Conservation status by state

Status: S2Q: Status is uncertain but is somewhere between the following rankings: Uncertain taxonomy: ⚘ 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) ⚘

Showy Goldenbanner: A Rare California Native Worth Growing

If you’re looking to add a splash of sunshine to your California native garden, meet the showy goldenbanner (Thermopsis robusta) – a perennial beauty that’s as rare as it is stunning. This golden-flowered native deserves a spot in more gardens, but there’s an important catch we need to discuss first.

What Makes Showy Goldenbanner Special

Showy goldenbanner is a herbaceous perennial forb that produces bright yellow, pea-like flowers arranged in showy terminal clusters. The blooms typically appear from late spring to early summer, creating a spectacular display that lives up to the plant’s common name. Its attractive trifoliate leaves (think three-leaflet clusters) provide a lovely backdrop for those golden blooms and maintain visual interest throughout the growing season.

As a member of the legume family, this plant has the added bonus of fixing nitrogen in the soil, making it a valuable addition to any native plant community.

Where Does It Come From?

Showy goldenbanner is exclusively native to California, making it a true Golden State original. You’ll find it naturally occurring in the Sierra Nevada mountains, where it has adapted to the unique conditions of this spectacular mountain range.

The Conservation Reality Check

Here’s where we need to have an important conversation. Showy goldenbanner has a conservation status of S2Q, which indicates some level of rarity or conservation concern. This means that while we absolutely encourage growing this beautiful native, it’s crucial that you source your plants or seeds responsibly.

What does responsibly sourced mean? Look for:

  • Reputable native plant nurseries that propagate their own stock
  • Seeds collected legally with proper permits
  • Plants that are clearly nursery-propagated, not wild-collected
  • Suppliers who can provide information about the provenance of their material

Why Grow Showy Goldenbanner?

Beyond its stunning appearance, showy goldenbanner offers several compelling reasons to include it in your landscape:

  • Pollinator magnet: Those bright yellow flowers are like beacons for native bees and other beneficial insects
  • Drought tolerance: Once established, it requires minimal supplemental watering
  • Low maintenance: As a native, it’s adapted to local conditions and needs little fussing
  • Soil improvement: Its nitrogen-fixing abilities benefit neighboring plants
  • Conservation value: By growing it, you’re helping preserve genetic diversity of this rare species

Perfect Garden Companions

Showy goldenbanner shines in native California gardens, wildflower meadows, and naturalized landscapes. It pairs beautifully with other California natives like:

  • California poppies for a golden color theme
  • Native bunch grasses for textural contrast
  • Ceanothus species for complementary blue flowers
  • Other Sierra Nevada natives for an authentic mountain meadow feel

Growing Conditions and Care

Showy goldenbanner is relatively adaptable but has some preferences that will help it thrive:

Sunlight: Full sun to partial shade, though it blooms best with plenty of morning sun

Soil: Well-draining soil is essential – it won’t tolerate soggy conditions. Sandy or rocky soils that mimic its mountain habitat work well

Water: Moderate water during establishment, then quite drought-tolerant. Deep, infrequent watering is preferred over frequent shallow watering

Climate: Hardy in USDA zones 6-9, making it suitable for most of California’s diverse climate zones

Planting and Propagation Tips

Getting showy goldenbanner established requires a bit of patience, but it’s worth the effort:

  • From seed: Seeds may benefit from scarification (lightly scratching the seed coat) to improve germination. Fall sowing often works best, allowing natural winter stratification
  • From plants: Spring planting gives the best establishment success. Dig holes twice as wide as the root ball but no deeper
  • Spacing: Allow 2-3 feet between plants to give them room to spread naturally
  • Mulching: A light mulch of decomposed granite or small gravel mimics natural conditions and helps with drainage

Maintenance Made Easy

Once established, showy goldenbanner is refreshingly low-maintenance:

  • Deadhead spent flowers if you want to prevent self-seeding (though the seedpods can be attractive too)
  • Cut back in late fall or early spring before new growth emerges
  • Divide every 3-4 years if clumps become overcrowded
  • Watch for any signs of root rot if drainage is poor

The Bottom Line

Showy goldenbanner is a stellar choice for California gardeners who want to support native biodiversity while adding spectacular color to their landscapes. Its rarity makes responsible sourcing non-negotiable, but the effort is worthwhile. By growing this beautiful native, you’re not just creating a stunning garden – you’re participating in conservation and supporting the pollinators and wildlife that depend on California’s native plant communities.

Remember: source responsibly, plant thoughtfully, and enjoy watching this golden beauty attract clouds of happy pollinators to your garden!

Showy Goldenbanner

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Thermopsis R. Br. - goldenbanner

Species

Thermopsis robusta Howell - showy goldenbanner

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