I’ve added a new link (on the right-hand side of the page) to a Canadian website, Botany Photo of the Day, run out of the University of British Columbia Botanical Garden that features photos from around the world.
The answer to my question about the name of the salvia I’d been given came through the post – the latest issue of NZ Gardener has it under the “Pick now” section.
Salvia confertiflora has flower spikes that can reach up to 60cm long, with the plant itself reaching up to 2m. It is also known as red velvet sage and is native to Brazil.
And Laurie Jeyes kindly offered the reason why my potted chrysanthemum has grown so tall in the garden – the “dwarfing chemicals” used by the original growers have worn off!
Anyone interested in finding out a bit more about plant growth retardants (PGRs) can read this article from the University of Massachusetts.