It’s not too early to start thinking about late blight. No relation to early blight, with which it shares a last name, late blight has become a perennial disease since infected tomato plants were shipped from southern greenhouses to the Northeast in May 2009. Prior to that, late blight was uncommon, but now we seem to be able to bank on its arrival each August. The fact that it is a seasonal immigrant is worth noting, since most garden diseases (such as early blight) are already here in the soil.
Gardeners and produce growers make a fuss about late blight because it has the potential to kill acres of tomatoes and potatoes in a matter of days; its fearsome reputation is well-deserved. Given the botanical name Phytophthora infestans, “highly contagious plant destroyer,” it is what laid waste to the Irish potato crop from 1844 to 1846, leading to a devastating famine. » Continue Reading.