When pruning during growing season, disinfect pruning tools after each cut with rubbing alcohol or a 10% bleach solution (one part household bleach to nine parts water, equivalent to 1.5 cups bleach to 1 gallon of water) to avoid spreading the disease. However, remove rapidly advancing infections on young, very susceptible cultivars of pear, Asian pear and some apple varieties as soon as possible in the spring when weather is dry. Recommended time to prune out fire blight infections is mid- winter when bacteria is in dormant state. If infection does occur, prune infected twigs and branches. Early detection is critical for management of disease.

Monitor often in spring and again in mid-winter.

Fertilize only if warranted via soil testing excess nitrogen encourages lush new growth which is more susceptible to the disease.

Very unfortunately, there is no cure for this disease, so prevention and early management are key. As the bacteria spreads, cankers appear as sunken or cracked area on branches and the cycle is ready to repeat. Symptoms of fire blight are wilting shoots, cankers on branches and blackened leaves, giving the trees a scorched appearance! Young twigs and branches die from the terminal end and may bend at the tip to look like a shepherds hook, while the dead leaves remain on the branches both ugly, tell-tale signs.

Other major means of infections are open wounds, perhaps caused by storm damage, rain splash and pruning equipment. This is the primary way the disease is spread- ooze to insect to blossoms. In spring, when temperatures get above 60 degrees and conditions are wet and humid, the cankers begin to ooze, attracting insects to it. The fire blight bacterium over winters in cankers on infected host plants.

Most susceptible are apple, crabapple, pear and ornamental pear trees, however other host plants include cotoneaster, hawthorn, flowering quince, raspberry, blackberry, mountain ash and spiraea. Fire Blight ( Erwinia amylovora) is a devastating, yet common bacterial disease affecting an estimated 75 species of plants in the Rosaceae family. We are seeing some unfortunate incidents of fire blight in our area, very much connected to the extended rainy spring we experienced.

Fire blight on crabapple trees