North America Native Plant

Hartweg’s Locust

Botanical name: Robinia viscosa var. hartwegii

USDA symbol: ROVIH2

Life cycle: perennial

Habit: shrub

Native status: Native to the lower 48 states  

Synonyms: Robinia hartwegii Koehne (ROHA)   

Hartweg’s Locust: A Rare Native Shrub Worth Knowing Meet Hartweg’s locust (Robinia viscosa var. hartwegii), a fascinating native shrub that’s flying under the radar in most gardening circles. This perennial woody plant represents a special variety of the clammy locust family, and while it might not be the most well-known ...

Rare plant alert!

Region: Conservation status by state

Status: S3T2: Status is uncertain but is somewhere between the following rankings: 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) ⚘ 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 ⚘

Hartweg’s Locust: A Rare Native Shrub Worth Knowing

Meet Hartweg’s locust (Robinia viscosa var. hartwegii), a fascinating native shrub that’s flying under the radar in most gardening circles. This perennial woody plant represents a special variety of the clammy locust family, and while it might not be the most well-known native species, it has some interesting qualities that make it worth considering for the right garden situation.

Where Does Hartweg’s Locust Call Home?

This native beauty has a rather exclusive address – you’ll find Hartweg’s locust naturally growing in just two southeastern states: North Carolina and South Carolina. Its limited geographic distribution makes it a true regional specialty, adding a touch of local character to gardens within its native range.

What Makes This Plant Special?

Hartweg’s locust grows as a multi-stemmed shrub, typically reaching heights of 13 to 16 feet under normal conditions, though it can sometimes stretch taller depending on environmental factors. Like other members of the Robinia family, it’s a perennial that will grace your garden year after year once established.

The plant is also known by its scientific synonym, Robinia hartwegii Koehne, though Hartweg’s locust rolls off the tongue much more easily!

A Word About Rarity

Here’s something important to consider: Hartweg’s locust has a Global Conservation Status of S3T2, indicating it has some level of conservation concern. If you’re interested in growing this native species, it’s crucial to source it responsibly from reputable native plant nurseries that propagate their stock rather than wild-collect it. Never harvest from wild populations!

Should You Grow Hartweg’s Locust?

The honest truth? Information about growing this specific variety is quite limited, which presents both challenges and opportunities for adventurous gardeners. Here’s what we do know:

  • It’s a true native species, making it an excellent choice for supporting local ecosystems
  • As a member of the legume family, it likely helps improve soil nitrogen levels
  • Its shrub form makes it suitable for mixed borders, naturalized areas, or native plant gardens
  • Being native to the Carolinas, it’s adapted to southeastern growing conditions

Growing Challenges and Considerations

The biggest challenge with Hartweg’s locust is the limited availability of specific growing information and plant material. Since detailed care instructions aren’t widely documented, you’d essentially be gardening with a bit of mystery and experimentation.

If you’re determined to try growing this rare native, your best bet is to:

  • Contact specialized native plant nurseries in the Carolinas
  • Connect with local native plant societies for growing experiences
  • Start with basic legume family care principles while observing how your plant responds

The Bottom Line

Hartweg’s locust represents one of those intriguing native plants that serious native gardeners and plant collectors might want to seek out, especially if you’re gardening within its natural range. While we can’t provide a detailed growing guide due to limited specific information, supporting rare native species through responsible cultivation is always a worthy endeavor.

Just remember: if you can’t find this particular variety easily, there are other native Robinia species and southeastern native shrubs that might be more readily available and better documented for your native garden plans!

Hartweg’s Locust

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

Robinia L. - locust

Species

Robinia viscosa Vent. - clammy locust

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