Excellenz von Schubert (Photo & Text)
For the first several years it grew here, EvS suffered dreadfully from Chlorosis. We treated it with soil sulfur, which addressed the problem, but only for a short time.
A few years back, it just quit going chlorotic. Nothing here altered, it just stopped having white leaves. Not that the foliage is Exhibition-perfect, but it's fine for the garden, and very good most of the time.
It blooms well through most of the year, is wonderfully fragrant, and does well in a vase. Blooming fairly well right now, in fact. :-)