Ageratina altissima (White Snakeroot)

Ageratina altissima (White Snakeroot) is a clump-forming, spreading, herbaceous perennial boasting flat-topped clusters of small, fluffy, bright white flowers in summer and fall.

Ageratina altissima (White Snakeroot) is a clump-forming, spreading, herbaceous perennial boasting flat-topped clusters of small, fluffy, bright white flowers in summer and fall. Borne atop erect, strong branching stems, the long-lasting blossoms are attractive to bees, butterflies and moths in search of nectar. Long-stalked, sharp-toothed, gray-green, nettle like leaves, 3-6 in. long (7-15 cm), are paired along the stems. Native to North America, White Snakeroot provides a wonderful garden presence and late season flowers at a time when choices may be limited. Use it in the informal setting of a cottage garden or allow it to naturalize in a woodland garden.

  • Grows up to 3-5 ft. tall (90-150 cm) and 2-4 ft. wide (60-120 cm). Will spread by rhizomes and self-seeding where happy.
  • Performs best in part shade in humus-rich, moist, alkaline soils.
  • Very useful and adaptable in the garden, this is an excellent choice as an accent plant, or for mixed borders, cottage gardens, woodland gardens, wild gardens and naturalized areas.
  • No serious insect or disease problems. Deer resistant.
  • Cut back faded flower stems to base to avoid any unwanted self-seeding.
  • Propagate by seed or division, in spring.
  • White Snakeroot causes the trembles in cattle and milk sickness in humans.
  • Native to North America.

Requirements

Hardiness 3
– 8

Heat Zones 2
– 8

Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17
Plant Type Perennials
Plant Family Eupatorium – Joe-Pye Weeds
Exposure Partial Sun
Season of Interest Summer (Mid,Late)Fall
Height 3'
– 5'
(90cm
– 150cm)
Spread 2'
– 4'
(60cm
– 120cm)
Spacing 48″ (120cm)
Water Needs Low, Average
Maintenance Low
Soil Type Chalk, Clay, Loam
Soil pH Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Poorly Drained
Characteristics Showy
Native Plants United States, Midwest, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin, Northeast, Connecticut, Delaware, Maine, Massachusetts, Maryland, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Southeast, Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, West Virginia, Southwest, Oklahoma, Texas
Tolerance Deer
Attracts Bees, Butterflies
Garden Uses Beds and Borders
Garden Styles Informal and Cottage, Prairie and Meadow