Common Diseases of Ornamental Pear Trees and How to Manage Them

Overview

Bacterial and fungal diseases can deform leaves and blossoms, cause dieback, or kill ornamental pears. Cultural practices combined with targeted treatments provide control.

Fire Blight

Bacterial; appears in wet, humid spring during bloom. Insects spread from cankers. Flowers/leaves turn brown but cling; branches blacken. Prune 8–10 inches below infection in dormancy. Disinfect tools between cuts (alcohol or 1:9 bleach). Avoid spring fertilizing; fertilize lightly in fall. Apply copper fungicides in winter, streptomycin products during growing season.

Entomosporium Leaf Spot

Fungal; small red spots on older leaves develop white spore centers. Causes premature leaf drop. Prune diseased foliage, disinfect tools, remove fallen leaves. Improve air circulation with proper spacing and no groundcover. Avoid overhead watering. Use copper or chlorothalonil fungicides if needed.

Bacterial Blight & Canker

Black lesions on stems/flowers; cankers on branches may kill tree. Occurs in wet springs. No chemical cure. Prune and discard infected branches. Water at soil level, keep foliage dry. If cankers appear, tree likely dies—remove it.

Cotton Root Rot (Texas Root Rot)

Soil-borne fungus rots entire taproot. Sudden wilting and death. No chemical control. Confirm via extension office. Remove infected trees; replant only resistant species in that area.