North America Native Plant

San Clemente Island Buckwheat

Botanical name: Eriogonum giganteum var. formosum

USDA symbol: ERGIF

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Eriogonum giganteum S. Watson ssp. formosum (Brandegee) P.H. Raven (ERGIF2)   

San Clemente Island Buckwheat: A Rare Treasure for Your California Garden Meet one of California’s most exclusive native plants: the San Clemente Island buckwheat (Eriogonum giganteum var. formosum). This stunning shrub isn’t just another pretty face in the garden world – it’s a genuine rarity that brings both beauty and ...

Rare plant alert!

Region: Conservation status by state

Status: S2T2: Status is uncertain but is somewhere between the following rankings: 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) ⚘ 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) ⚘

San Clemente Island Buckwheat: A Rare Treasure for Your California Garden

Meet one of California’s most exclusive native plants: the San Clemente Island buckwheat (Eriogonum giganteum var. formosum). This stunning shrub isn’t just another pretty face in the garden world – it’s a genuine rarity that brings both beauty and ecological value to the right landscape.

What Makes This Plant Special?

The San Clemente Island buckwheat is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet tall. What sets this variety apart is its striking silver-gray foliage that creates a beautiful backdrop for clusters of small white to pinkish flowers that bloom in summer. It’s like having a piece of island magic right in your backyard!

Where Does It Come From?

This remarkable plant is endemic to San Clemente Island, off the coast of California, making it a true California native. It’s found nowhere else in the world naturally, which adds to its special appeal for native plant enthusiasts.

A Word About Rarity

Here’s something important to know: San Clemente Island buckwheat has a Global Conservation Status of S2T2, indicating it’s quite rare. If you’re considering adding this beauty to your garden, please make sure you’re sourcing it from reputable nurseries that propagate plants responsibly rather than collecting from wild populations. Every plant matters when we’re talking about conservation!

Why Grow San Clemente Island Buckwheat?

Despite its rarity (or perhaps because of it), this plant offers several compelling reasons to include it in your landscape:

  • Stunning aesthetic appeal with silvery foliage and delicate flower clusters
  • Excellent drought tolerance once established
  • Perfect for Mediterranean and xeriscape gardens
  • Attracts beneficial pollinators like bees and butterflies
  • Adds authentic California native character to your landscape
  • Relatively low maintenance once settled in

Growing Conditions and Care

San Clemente Island buckwheat thrives in USDA hardiness zones 9-11, making it perfect for coastal and inland California gardens. Here’s what this island native needs to flourish:

  • Sunlight: Full sun exposure for best growth and flowering
  • Soil: Well-draining soil is absolutely essential – this plant hates wet feet
  • Water: Drought tolerant once established, but appreciates some water during its first year
  • Climate: Handles coastal conditions beautifully and adapts well to Mediterranean climates

Planting and Care Tips

Want to give your San Clemente Island buckwheat the best start? Follow these straightforward guidelines:

  • Plant in fall when temperatures are cooler and rainfall is more likely
  • Ensure excellent drainage – amend heavy clay soils with gravel or sand if necessary
  • Water regularly the first year to help establish roots, then reduce watering significantly
  • Prune lightly after flowering to maintain shape and encourage new growth
  • Avoid over-fertilizing, as native plants typically prefer lean soils

Garden Design Ideas

This versatile shrub works wonderfully in several landscape styles:

  • Native plant gardens: Pairs beautifully with other California natives like salvias and penstemons
  • Coastal gardens: Handles salt air and wind like a champ
  • Xeriscape designs: Perfect for water-wise landscaping
  • Pollinator gardens: Creates a buzzing hub of beneficial insect activity

Supporting Conservation Through Gardening

By choosing to grow San Clemente Island buckwheat from responsibly sourced plants, you’re not just adding beauty to your landscape – you’re participating in conservation. Home gardens can serve as genetic repositories and help ensure these rare plants have a future beyond their native habitat.

Remember, the key is sourcing your plants ethically. Look for nurseries that specialize in native plants and can verify their propagation methods. Your garden can be a sanctuary for this remarkable California native while you enjoy its unique beauty and ecological benefits.

San Clemente Island Buckwheat

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Polygonales

Family

Polygonaceae Juss. - Buckwheat family

Genus

Eriogonum Michx. - buckwheat

Species

Eriogonum giganteum S. Watson - St. Catherine's lace

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