Fire blight, Erwinia amylovora, is a very destructive bacterial disease of trees in the rosaceous family, such as apple and pear trees. Fire blight usually starts with the blossoms or flowers and moves into the twigs and branches causing infected twigs to bend over, creating a “shepherd’s crook” appearance. Warm rainy springs and open wounds allow rapid spread of the disease. Fire blight is most severe before and during bloom when spring temperatures are warmer than average. If not managed, fire blight can destroy the blossoms, fruit, and stems of the plant, and even kill the plant.