Question: Some of my pyracantha’s branches have suddenly died. It seems to affect 10- to 12-inch parts of the plant, and the damage is scattered all over the plant. Is it an insect or disease?

Answer: It’s probably fire blight. Pyracanthas, like other members of the rose family, are susceptible to it. It enters the plants carried by bees as they pollinate the flowers. Spray with agricultural streptomycin while they’re in full flower. Prune out the dead tissues during the growing season, cutting back into healthy wood. Disinfect your pruning tools by dipping them in a 10-percent solution of chlorine bleach between each cut.