All that rain could help spread the mold that caused the Irish potato famine

Jennifer Forman Orth alerts us that state officials are on the lookout for late blight disease, a mold that kills both potatoes and tomatoes. She says it's already been spotted in Massachusetts and that people growing either type of plant should watch for it - and report any suspected cases to the state:

Symptoms of late blight include small olive green or brown lesions on the upper surface of the foliage or the stems. Under moist conditions, there is a white, fuzzy growth on the underside of the leaves where the lesions occur, but the absence of this growth does not rule out late blight. Eventually the lesions turn black, leaves start to die, and then the entire plant dies.

The disease is caused by Phytophthora infestans, which killed off much of the Irish potato crop in the 1840s. And guess how it spreads?

[T]hrough splashing rain or wind currents. Spores can disperse from one to several miles from the point of origin, with the infection spreading most efficiently in conditions of high moisture and temperatures ranging from 60° to 80°F.