Posted: 17/01/2014 at 16:26
Then try one called Black Adder. It's about 4' tall...maybe taller......with inky blue flowers with black touches. It's a lovely thing. It may not flower so.profusely as it would in full sun. In the autumn you can carefully divide it and pot it up....it won't survive the winter in cold areas. Another variety is Sangria which is taller and has pink flowers.
Miscanthus variegatus is a tall white and green vsriegated grass that adds height and nice contrast to Black Adder. You might like to try that
Re aconitum I have early amd late flowerimg varieties. One flowers from July for me. The other in late August.