Plant guide

White Snakeroot.

Ageratina altissima

Pronounced ah-jer-ah-TEE-nah al-TISS-ih-mah

Also known as Richweed, Snakeroot, White Sanicle, White Snakeroot, White Snakeroot

White snakeroot is a hardy perennial native to North America that produces clusters of fuzzy white flowers in late summer. It is a woodland plant that spreads easily through rhizomes and seeds. You will find it thrives in shaded areas with consistent moisture.

At a glance

Care level: Easy
Plant type: Perennial
Light: Partial shade to full shade
Indoor light: Medium light
Water: Every 3 to 7 days
Mature size: 5 feet
Growth rate: Fast

Care

Keep the soil consistently moist to mimic its natural woodland habitat. Watch for wilting during dry spells, as this plant does not tolerate drought well. It can become aggressive in garden settings, so keep an eye on its spread.

Watering: Water whenever the top inch of soil feels dry to the touch.
Feeding: A light application of compost in early spring is usually plenty.
Pruning: Cut the plant back to the ground in late winter or early spring.
Repotting: If grown in a container, move to a larger pot once the roots fill the current space.
Soil: Rich, moist, well draining soil
Soil pH: 6.0 to 7.5

Safety

Pets: This plant is toxic to cats and dogs if ingested.

How to identify it

Opposite, serrated, heart shaped leaves
Clusters of small white flower heads
Stems are smooth and often purple tinted
Mature height reaches 3 to 5 feet

Science

Family: Asteraceae
Genus: Ageratina
Order: Asterales
Class: Magnoliopsida

Taxonomy resolved against GBIF.

Also in

Is your white snakeroot looking unwell?

This page is a general guide. Pocket Botanist diagnoses problems from a photo of your actual plant, works out watering for your light and conditions, and reminds you when care is due.

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.