For some years I had a fine clump of Z. katherinae that came from
Christine Boulby who used to post here. It makes a very pleasing
hummock of silvery, sage-green foliage smothered in those wonderful
carmine-backed, white flowers that emit an incredible fragrance at
night. I was cold hardy enough here, but eventually it succumbed to
verticillium caused by the high humidity levels here. Fabulous thing
and not at all dissimilar to Z.. oavta. Personally I can't understand
why even the annual forms aren't more widely grown. They're easy to
grow and immensely rewarding.