Ageratina altissima

RHS Plant Profile
white snakeroot

Save a plant

Where do you want to save Ageratina altissima?

Plants I own
Wishlist
Go to My Plants
white snakeroot RHS
white snakeroot visionspictures.com

Other common names

deerwort, hardy age, milk ipecac, mist flower, nettle-leaved hemp agrimony, rich weed, white sanicle

Synonyms

Eupatorium urticifolium
Eupatorium ageratoides
Eupatorium rugosum
Eupatorium album misapplied
Eupatorium fraseri misapplied
Eupatorium rugosum album
Ageratum altissimum

Plants for pollinators
Herbaceous Perennial
Buy this from Plant Nurseries
3 Suppliers

A tall herbaceous perennial to about 1.7m with brown stems and grey-green, nettle like leaves. Umbel-like clusters of small, white, long-lived flowers appear in summer and early autumn

Position

Partial shade

Soil Types

Chalk, Clay, Loam

Max Height

1.5-2.5 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
2–5 years
Max Spread
0.5-1 metres
Max Height
1.5-2.5 metres

Growing Conditions

Chalk Clay Loam
Moisture
Moist but well–drained or Poorly–drained
pH
Alkaline or Neutral

Position

Partial shade
Aspect
East–facing or West–facing
Exposure
Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

  • H1A: under glass all year (>15C)
  • H1B: can be grown outside in the summer (10 - 15)
  • H1C: can be grown outside in the summer (5 - 10)
  • H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
  • H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
  • H4: hardy through most of the UK (-10 to -5)
  • H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
  • H6: hardy in all of UK and northern Europe (-20 to -15)
  • H7: hardy in the severest European continental climates (< -20)
H5

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Asteraceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Bushy
Genus
Ageratina are shrubs or herbaceous perennials with opposite leaves and small tubular flowers borne in corymbs
Name Status
Correct
Plant Range
North America

How to Grow

Cultivation

The ideal site is a moist, alkaline soil in partial shade; frost may damage new shoots

Propagation

Propagate by seed or division, in spring

Suggested planting locations and garden types

  • Wildlife gardens
  • Cottage and informal garden
  • Flower borders and beds

Pruning

Cut back faded flower stems to base

Pests

May be susceptible to slugs and aphids

Diseases

Generally disease-free