Dwarf Butter Beans Wilt
Each year I plant my dwarf butter beans in my plot they begin to wither at the time just before flowering. . . . I usually lose more than 50% of my plants and get hardly any crop. . . other crop plants in the plot seem unaffected during their growth cycle.
Certified GKH Gardening Expert
It sounds like they may have Fusarium Wilt. The ones that are not affected may be in uninfected beds. This article will explain more about it: