Q: I have a large bed of annual vinca where more than half of the plants have died. Our helpful county extension service agents identified the problem as Phytophthora aerial stem blight. A vine has ...

Over many decades, we have come to count on colorful, sturdy vinca (Catharanthus roseus) as the workhorse of our summer gardens. With its pretty pink, white and purple blooms clustered en masse on a ...