I have a small batch of these ready to go on the nursery. Intense violet blue flowers on branching hoary pale stems. The foliage is rather good.
Like other West Coast Delphiniums, this is unlikely to do well under ordinary garden conditions but if you're good with Californian or South African bulbs there's no reason why this shouldn't do well for you.
A well drained soil in full sun is probably right - drier in summer, moister in winter. Here they've grown well in the tunnel with no special care.
I won't be sending these out in flower - way too tall and brittle