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Rough eupatorium

Name: Rough eupatorium
Brand: Akène
SKU: AKE-SEMGR1
Price: 4.99 CAD
Availability: InStock

Common name White Snakeroot

Latin name Ageratina altissima

Quantity per packet Minimum 75 seeds

This native woodland perennial enhances biodiversity by attracting pollinators when few other flowers remain in bloom. Its dense foliage and graceful flowers also enrich woodland gardens and ecological landscapes throughout Canada.

Product information

Product
identification

Common nameWhite Snakeroot

Latin nameAgeratina altissima

FamilyAsteraceae

TypeNative perennial

CyclePerennial

Quantity per packMinimum 75 seeds

Code produitAKENE-0020

Product
description

White Snakeroot (Ageratina altissima) is a native woodland perennial that brings airy clusters of bright white flowers to partially shaded gardens. Its delicate blooms appear from late summer into early fall, providing fresh color at a time when many other native perennials have already finished flowering. This late-season display makes it an invaluable nectar source for native bees, butterflies, hoverflies, and many other beneficial pollinators. Its natural upright habit and dense foliage blend beautifully into woodland gardens, forest edges, and biodiversity-focused landscapes.

White Snakeroot thrives in humus-rich, cool, well-drained soils and performs best in light shade to partial shade. It naturally grows in organic woodland soils and requires very little maintenance once established. Its moderate growth habit allows it to gradually form attractive natural colonies without becoming difficult to manage. A mulch of fallen leaves or compost helps retain soil moisture while recreating the woodland conditions it prefers. This adaptable native perennial is an excellent choice for naturalizing shaded areas and enriching native plantings.

In the garden, White Snakeroot combines beautifully with Ostrich Fern, Wild Columbine, Foamflower, and Woodland Phlox to create layered woodland plantings filled with texture and season-long interest. Its late bloom extends the flowering season while providing an essential food source for late-season pollinators. It also performs well in large containers, woodland borders, and ecological restoration projects where supporting beneficial wildlife is a priority. With its exceptional hardiness, naturalizing ability, and significant ecological value, Ageratina altissima is an outstanding native perennial for woodland and ecological gardens throughout Canada.

Sowing
guide

Sowing periodAutumn or spring after cold stratification

Best time

Spring after the last frost

Sowing depthSurface sow

Spacing / density

45 to 60 cm (18 to 24 in)

Germination temperature18 to 22°C (64 to 72°F)

Germination time14 to 30 days

Propagation

Propagate by seed or by dividing established colonies in spring. Mature plants also naturalize readily through self-seeding.

Growing
method

Sow White Snakeroot seeds in autumn or spring after cold stratification to improve germination. Surface sow the seeds, as light promotes successful germination. Keep the growing medium evenly moist at 18 to 22°C (64 to 72°F). Germination generally occurs within 14 to 30 days. Transplant seedlings into humus-rich, well-drained soil in light shade or partial shade. Once established, this native perennial often self-seeds naturally and forms attractive colonies in woodland gardens.

Soil
and care

ExposureLight shade to partial shade

Soil

Humus-rich, well-drained soil. This species prefers organic woodland soils that remain cool throughout the growing season.

Soil pHAcidic to neutral

Watering

Water moderately to keep the soil consistently cool, especially during hot, dry weather. Once established, this perennial tolerates short dry periods but performs best with even moisture.

Fertilization

A light application of mature compost in spring is generally sufficient. This woodland perennial thrives in organically rich soils without requiring additional fertilizer.

Care levelModerate

In spring, remove the previous year's dry stems to encourage vigorous new growth. Maintain cool soil with organic mulch and water during extended dry periods. Once established, White Snakeroot requires very little maintenance. Leave the seed heads in place during autumn to feed wildlife and encourage natural reseeding. The dry stems also provide winter shelter for beneficial insects.

Container
growing

Recommended pot size

30 cm (12 in)

White Snakeroot grows well in containers at least 30 cm (12 in) deep filled with an organic-rich growing medium. Place the container in light shade or partial shade to mimic its natural woodland habitat. Keep the soil evenly moist without becoming waterlogged and apply organic mulch to reduce evaporation. This native perennial creates an attractive woodland display while drawing a wide diversity of pollinators late in the season.

Bloom,
harvest
and garden

Its late-season white flowers brighten shaded gardens while providing an essential nectar source for pollinators when few other native plants are still blooming. Its natural habit and ability to naturalize make it an outstanding woodland perennial.

Garden use

White Snakeroot is ideal for woodland gardens, forest edges, pollinator gardens, and naturalization projects. It combines beautifully with ferns, Wild Columbine, Foamflower, and other native woodland perennials. Its late-season flowers brighten shaded areas while supporting beneficial insects through autumn. It is an excellent choice for creating diverse, wildlife-friendly native plant communities.

Bloom period

Airy white flower clusters bloom from July through September, brightening shaded gardens while attracting abundant pollinators.

Flower colorWhite

Foliage colorGreen

Harvest

September to October

Wildlife appealButterflies and bees

Size
and facts

Height30 to 120 cm (12 to 48 in.)

Spread45 to 75 cm (18 to 30 in)

Growth rateModerate

Hardiness zoneUSDA Zones 3–8

Minimum temperature-40°C (-40°F)

Foliage typeDeciduous

Papillonstrue

Insectes utilestrue

Résistant aux cerfstrue

Planting
partners

Good companions

Wild Columbine, Foamflower, Woodland Phlox, Ostrich Fern

Avoid planting with

Lavender, Cotton Lavender, Rosemary, Sedum

Recipe
and inspiration

White Snakeroot is not used as a culinary plant, and parts of the plant are considered toxic to livestock. Today it is grown primarily for its exceptional ecological value in woodland and naturalized gardens. Its late-season flowers provide an important nectar source for pollinators when many other perennials have finished blooming, making it an excellent plant for supporting biodiversity.

Frequently asked questions

When should I sow White Snakeroot seeds? +

White Snakeroot seeds are best sown in autumn or spring after cold stratification. This treatment significantly improves germination.

Does White Snakeroot attract pollinators? +

Yes. Its abundant late-summer flowers attract a wide variety of bees, butterflies, hoverflies, and other beneficial pollinators when few other flowers remain.

Can White Snakeroot grow in shade? +

Yes. White Snakeroot naturally grows in open woodlands and thrives in light shade to partial shade. It also tolerates some direct sun if the soil remains cool and moist.

Is White Snakeroot suitable for naturalistic gardens? +

Absolutely. It is highly recommended for ecological gardens, woodland restoration, and naturalized landscapes where supporting biodiversity is a priority.

Is White Snakeroot hardy in Canada? +

Yes. White Snakeroot is fully hardy throughout Canada and returns reliably every year, even after harsh winters.

The availability of our seeds varies depending on seasonal availability, production schedules and supplier inventory. Certain varieties may only be offered for a limited time based on their natural growth cycle, sowing period or available stock. These product pages are designed to help and inspire gardeners in choosing the right seeds for vegetable gardens, flower beds, pollinator gardens, container growing, naturalization projects and sustainable outdoor spaces.