Hello Gardeners, I’m Amanda McNulty with Clemson Extension and Making It Grow . Fire blight affects members of the rose family – that means apples, pears, and plums. It is caused by a native, not introduced, bacterium that overwinters cankers and becomes active when spring brings warm temperatures and rain. Bees actually spread it from flower to flower and It causes plants to die back from the terminals – often the branch tip looks like a shepherd’s crook. Although we think of Bradford pear