Cordyline australis is quite easy to grow and hardy once it reaches a reasonable size. They are often grown in containers which limits their growth. The heads divide after flowering leaving a branched structure.
The castor oil plant, ricinus communis, photographed in July 2009. In October 2010 the seeds have been gathered from last summer's plants. These are going into the fridge and will be planted in the spring for next year.
Echiums are easy to grow, but will require winter
protection in all but the mildest areas. They usually flower in their second year, and will die
after flowering. Masses of seeds are produced which self propagate
generously.

The hard winter frosts of 2009/10 have not been good for these plants. Only three in the greenhouse survived.
Update 24th October 2010. There are lots of plants coming on for next year. Will try to protect some from winter frosts.
Update August 2011. Only one echium flowered this year. It survived last year's cold winter in the greenhouse.