Taller at 1,6m Aconitum carmichaellii (Wilsonii group) Spätlese bears attractive spires of light blue, hooded flowers from September to October.
Pruning Aconitum (Monkshood or Wolfsbane). Cut the faded flower stems just above the ground when flowering is finished.
How to divide aconitum
Aconitum needs to be divided roughly every 4 years to maintain its vigour. Divide aconitum in spring when new growth starts to emerge. Dig up clumps and pull the tuberous roots apart by hand. Replant the divided parts and water thoroughly. Wear gloves when dividing aconitum.
The tuberous roots of aconitum are very poisonous.