[From A Year of Roses, by Stephen Scanniello, p. 110:] Remove lower foliage three to six inches up from the ground... black spot starts in the lower regions of a rosebush... [Scanniello discusses different remedies and their pros and cons, so please see text for more information.]

[From the June/July 1999 issue of Garden Design magazine, which has several articles/notes of interest to rose growers. One of these is an article by Stephen Scanniello, formerly curator of the Brooklyn Botanic Garden’s Cranford Rose Garden, about roses Josephine grew at Malmaison and that are still available today, p. 99:] Scientists have proven that R. foetida is most susceptible to foliage diseases and might even be the genetic source for black spot in other roses...