About

Ageratina altissima is a robust herbaceous perennial that grows up to 1.7 meters in height. It features brown stems and grey-green leaves that resemble those of stinging nettles. During the summer and early autumn, it produces clusters of small, white flowers arranged in umbels that persist for an extended period.

About the genus

Ageratina consists of shrubs or herbaceous perennials characterized by their opposite leaves and clusters of small tubular flowers arranged in corymbs.

Growing conditions

Sunlight
Partial shade
Soil type
Chalk, Clay, Loam
Soil pH
Alkaline, Neutral
Soil moisture
Moist but well-drained, Poorly-drained
Aspect
East-facing, West-facing
Exposure
Sheltered
UK hardiness
H5

Plant details

Plant type
Herbaceous Perennial
Habit
Bushy
Foliage
Deciduous
Height
1.5-2.5 metres
Spread
0.5-1 metres
Time to full height
2-5 years
Suggested uses
Wildlife gardens, Cottage and informal garden
Native to
North America

Care notes

Cultivation
The ideal site is a moist, alkaline soil in partial shade; frost may damage new shoots
Pruning
Cut back faded flower stems to base
Propagation
Propagate by seed or division, in spring
Pest resistance
May be susceptible to slugs and aphids
Disease resistance
Generally disease-free