Fall flowering perennial*


I have a beautiful perennial that grows by the fence in my garden…partial sun, mostly shade. It flowers every Fall, the last plant to flower, with beautiful purple flowers. We are in the north part of Toronto. We do not know what it is, but would love to plant one or two more along the fence.

Can you help, please?



Thank you for emailing a photo of your fall flowering perennial. This is an Azure Monkshood, Aconitum fischeri or charmichaelii. You are right, it is one of the last blue flowering plants of the season.  Each individual flower is shaped like a hood, thus the common name Monkshood.

It is best planted in the fall. The plants do not transplant well once established, but tuberous roots can be used for propagation by carefully separating them from their mother plants and transplanting them in the fall.

All aconitum have poisonous roots, leaves, and stems and gloves should be worn when handling the plant, especially the roots. You will also want to avoid planting  aconitum close to a vegetable garden.

Aconitum grow best in sun to part shade and grow 18″ to 24″ in height. They like their  soil to be consistently moist.

A second or third plant will look stunning in your garden in the fall.