North America Native Plant

Tall Rattlesnakeroot

Botanical name: Prenanthes altissima

USDA symbol: PRAL3

Life cycle: perennial

Habit: forb

Native status: Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Nabalus altissimus (L.) Hook. (NAAL3)  âš˜  Prenanthes altissima L. var. cinnamomea Fernald (PRALC)   

Tall Rattlesnakeroot: A Late-Blooming Native Wonder for Your Shade Garden If you’re searching for a native plant that brings life to your shade garden when most other flowers have called it quits for the season, meet tall rattlesnakeroot (Prenanthes altissima). This unassuming perennial might not win any beauty contests in ...

Tall Rattlesnakeroot: A Late-Blooming Native Wonder for Your Shade Garden

If you’re searching for a native plant that brings life to your shade garden when most other flowers have called it quits for the season, meet tall rattlesnakeroot (Prenanthes altissima). This unassuming perennial might not win any beauty contests in spring, but come late summer, it transforms into a graceful giant that pollinators absolutely adore.

What Exactly Is Tall Rattlesnakeroot?

Tall rattlesnakeroot is a native North American perennial forb – essentially a non-woody flowering plant that comes back year after year. Don’t let the intimidating name fool you; this plant has nothing to do with rattlesnakes! The rattlesnake part likely comes from the plant’s historical use in folk medicine, while tall is spot-on – this beauty can reach impressive heights of 3-8 feet.

Botanically known as Prenanthes altissima, this native gem belongs to the sunflower family and has earned its place in gardens across eastern North America through sheer persistence and late-season charm.

Where Does It Call Home?

This adaptable native has an impressive range, naturally occurring across much of eastern North America. You’ll find tall rattlesnakeroot thriving from southern Canada down through the eastern United States, including Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, and West Virginia. It’s also found in several Canadian provinces including New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec, and Labrador.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where tall rattlesnakeroot really shines – timing is everything! While most garden flowers are winding down in late summer, this native is just getting started. Its drooping, bell-shaped flowers in creamy white to pale yellow create an almost ethereal effect in the dappled light of woodland gardens.

The real magic happens when pollinators discover these late-season blooms. Bees, butterflies, and other beneficial insects flock to the flowers, making your garden a crucial pit stop when other nectar sources are scarce. It’s like running a 24-hour diner for pollinators when everywhere else has closed!

Perfect Spots for Planting

Tall rattlesnakeroot is wonderfully versatile when it comes to garden placement:

  • Woodland gardens: Its natural habitat makes it perfect for mimicking forest understory conditions
  • Shade gardens: Thrives in areas where sun-loving plants struggle
  • Native plant gardens: An essential component of authentic regional plant communities
  • Naturalized areas: Excellent for low-maintenance, wild-looking spaces
  • Rain gardens: Can handle varying moisture levels depending on your region

Growing Conditions Made Simple

One of the best things about tall rattlesnakeroot is its easygoing nature. This native adapts to a range of conditions but has some preferences:

  • Light: Partial to full shade (morning sun with afternoon shade works great)
  • Soil: Moist, well-draining soils with organic matter, but tolerates various soil types
  • Hardiness: Thrives in USDA zones 3-8
  • Moisture: Generally prefers consistent moisture but isn’t picky

Wetland Considerations

Interestingly, tall rattlesnakeroot’s relationship with water varies by region. In coastal areas and the Great Plains, it’s typically found in upland (non-wetland) conditions. However, in mountainous regions, the Midwest, and the Northeast, you might occasionally spot it in wetter areas. For home gardeners, this flexibility means it can adapt to various moisture conditions in your landscape.

Planting and Care Tips

Growing tall rattlesnakeroot is refreshingly straightforward:

  • Planting: Spring or fall planting works well; give plants 2-3 feet of space
  • Soil prep: Add compost or leaf mold to boost organic content
  • Watering: Water regularly the first year, then let nature take over
  • Maintenance: Minimal care needed once established – just let it do its thing!
  • Self-seeding: Don’t be surprised if it pops up in new spots; embrace the natural look or transplant seedlings

Is Tall Rattlesnakeroot Right for Your Garden?

This native is perfect for gardeners who love low-maintenance plants with ecological benefits. If you have shade to fill, want to support late-season pollinators, or are creating a native plant garden, tall rattlesnakeroot deserves a spot on your list.

However, if you prefer highly manicured gardens or need showy spring and summer color, this might not be your first choice. Its beauty is subtle and its bloom time specific – but that’s exactly what makes it special.

Consider tall rattlesnakeroot as the reliable friend of the plant world: maybe not the flashiest at the party, but always there when you need them most. Your late-summer garden (and the pollinators) will thank you for it!

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Atlantic and Gulf Coastal Plain

UPL

Obligate Upland - Plants with this status almost never occurs in wetlands

Eastern Mountains and Piedmont

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Great Plains

UPL

Obligate Upland - Plants with this status almost never occurs in wetlands

Midwest

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Northcentral & Northeast

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Tall Rattlesnakeroot

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

Prenanthes L. - rattlesnakeroot

Species

Prenanthes altissima L. - tall rattlesnakeroot

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