Details
V. bonariensis is a tall perennial with erect, branching stems to 2m in height, bearing sparse, oblong leaves and numerous branched clusters of small, purple flowers from summer to autumn.

Hardiness
H4 - Hardy through most of the UK (-10 to -5)

Aspect
South-facing or West-facing

Exposure
 
Exposed or Sheltered

Moisture
 
Moist but well-drained, Well-drained

Soil
 
Clay, Loam, Chalk, Sand

pH
 
Acid, Alkaline, Neutral

Size
Ultimate height
 
1.5-2.5 metres
 
Ultimate spread
 
0.1-0.5 metres
 
Time to ultimate height
 
2-5 years

How to grow
Cultivation
Grow in moist but well-drained or well-drained, moderately fertile soil in full sun. In cold areas, protect with a dry winter mulch
Propagation
Propagate by seed in pots at 18-21?C in autumn to early spring or let it self-seed
Suggested planting locations and garden types
Flower borders and beds Wall-side Borders Prairie Planting Gravel Garden City & Courtyard Gardens Coastal Cottage & Informal Garden

How to care
Pruning
Cut down in spring as new growth emerges from the base; deadhead in autumn if seed is not required
Pests
Generally pest free
Diseases
Generally disease free