North America Non-native Plant

Greater Herb Robert

Botanical name: Geranium yeoi

USDA symbol: GEYE

Life cycle: biennial

Habit: forb

Native status: Non-native, reproduces and persists in the wild in the lower 48 states  

Greater Herb Robert: What You Need to Know About Geranium yeoi If you’ve stumbled across the name greater herb robert or its botanical name Geranium yeoi, you might be wondering whether this plant deserves a spot in your garden. Let’s dive into what we know about this somewhat mysterious member ...

Greater Herb Robert: What You Need to Know About Geranium yeoi

If you’ve stumbled across the name greater herb robert or its botanical name Geranium yeoi, you might be wondering whether this plant deserves a spot in your garden. Let’s dive into what we know about this somewhat mysterious member of the geranium family.

The Basics: What Is Greater Herb Robert?

Geranium yeoi, commonly known as greater herb robert, is a biennial forb – which is just a fancy way of saying it’s a non-woody herbaceous plant that lives for two years. Like other forbs, it lacks the thick, woody stems you’d find on shrubs and trees, instead producing softer, more delicate growth that emerges from buds at or below ground level.

Where Does It Come From?

This plant isn’t a California native, despite being found growing wild in the Golden State. Geranium yeoi is what botanists call a naturalized species – it was introduced from somewhere else but has managed to establish itself and reproduce on its own in California’s landscapes.

The Challenge: Limited Growing Information

Here’s where things get a bit tricky for gardeners. Unlike well-known garden favorites, detailed cultivation information for Geranium yeoi is surprisingly scarce. We know it’s a biennial that can survive on its own in California conditions, but specific details about its preferred growing conditions, care requirements, and garden performance are largely undocumented in standard horticultural sources.

Should You Plant It?

Given the limited information available about this species, it’s difficult to make strong recommendations either way. While there’s no indication that Geranium yeoi is invasive or problematic, the lack of detailed growing guides means you’d be somewhat experimenting if you chose to cultivate it.

Consider Native Alternatives

Since Geranium yeoi isn’t native to California and reliable growing information is limited, you might want to consider some well-documented native geranium species instead. California has several beautiful native geraniums that are better understood by gardeners and provide known benefits to local wildlife:

  • Wild geranium (Geranium californicum)
  • Richardson’s geranium (Geranium richardsonii)
  • Sticky purple geranium (Geranium viscosissimum)

The Bottom Line

Geranium yeoi remains something of an enigma in the gardening world. While it’s managed to establish itself in California’s wild spaces, the lack of detailed cultivation information makes it a challenging choice for home gardeners. If you’re drawn to the geranium family, you’ll likely have better success and more support resources with either well-established garden varieties or California’s native geranium species.

Sometimes the most honest answer a gardening expert can give is we need to know more. In the case of greater herb robert, that’s exactly where we stand.

Greater Herb Robert

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

Geraniales

Family

Geraniaceae Juss. - Geranium family

Genus

Geranium L. - geranium

Species

Geranium yeoi Aedo & Muñoz Garm. - greater herb robert

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