LEAF PROBLEM ID - Ask Extension
MY ESPALIER PEAR TREES ARE HAVING SOME KIND OF PROBLEM WHICH I THINK IS PROBABLY FUNGAL BUT I’M NOT SURE, AND I DON’T KNOW WHAT KIND IF SO AND WHA...
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LEAF PROBLEM ID #923772
Asked January 19, 2026, 8:28 PM EST
MY ESPALIER PEAR TREES ARE HAVING SOME KIND OF PROBLEM WHICH I THINK IS PROBABLY FUNGAL BUT I’M NOT SURE, AND I DON’T KNOW WHAT KIND IF SO AND WHAT THE BEST TREATMENT WOULD BE. THE LEAVES HAVE EXTENSIVE DARK BROWN TO BLACK SPOTTING. CAN YOU HELP?
Multnomah County Oregon
Expert Response
A few things come to mind but you might have to do a little more digging to figure it out. First are the pear rust or blister mites that can cause a more or less symmetrical pattern on either side of the leaf mid-rib. Read the descriptions and see if it matches you observations: https://pnwhandbooks.org/insect/tree-fruit/pear/pear-eriophyid-mite
With very wet weather in the spring we have seen leaf blister but I am not sure this matches. Be aware that anything that happens early on pears - like obvious colorful spots - end up turning black in time. Here is that description: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-leaf-blister
I focus on the mites as the image has just one shoot with symptoms and not the other shoots in the background. It also tends to rule out heat stress, under-watering and similar issues.
With very wet weather in the spring we have seen leaf blister but I am not sure this matches. Be aware that anything that happens early on pears - like obvious colorful spots - end up turning black in time. Here is that description: https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-leaf-blister
I focus on the mites as the image has just one shoot with symptoms and not the other shoots in the background. It also tends to rule out heat stress, under-watering and similar issues.
