Pear Rust - Ask Extension
I've got a Bartlett pear tree that developed an extensive case of gymnosporangium Sabinae 2 years ago after bumper harvest the prior year. Almost no ...
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Pear Rust #927193
Asked March 31, 2026, 4:32 PM EDT
I've got a Bartlett pear tree that developed an extensive case of gymnosporangium Sabinae 2 years ago after bumper harvest the prior year. Almost no pears 2 years ago and last year one. Extensive orange spots with brown galls under leaves as the summer wore on 2 years ago, somewhat less last season. Very little leaf drop either of last 2 years. Using dormant oil in winter x 1 last few years. Trees are in bloom now. Getting different recommendations on what to spray with and when to treat this tree. I pick up up leaves and fruit meticulously and get pruning off the property. What spray would you use and when?
Clackamas County Oregon
Expert Response
Hi and thanks for your question about your pear tree. Your rust, also known as pear trellis rust has an alternate host of juniper which may show the following symptoms:
"Careful examination of infected plants reveals elongated, swollen galls on older wood. Needles may be shed from this swollen area and small or thin twigs may die if infected. Red to orange, jelly-like telia are extruded from the galls during wet weather in early spring."
If you have a juniper within 2 miles, you will probably just be re-infected each year. Cultural control consists of removing infected pear leaves before sporulation in the fall.
Unfortunately, there are no products labeled for home use of this problem. The best solution is to remove juniper trees in the area. When I told my neighbor of the problem and showed here the rust, she actually removed the tree. I do still get some of the rust , but I am very careful to remove the infected leaves, keep them raked off the ground and we still get a crop each year.
If removing local junipers is not an option, you might want to consider an alternate fruiting tree.
https://hortsense.cahnrs.wsu.edu/fact-sheet/pear-pear-trellis-rust/
I wish the news was better, as I too am afraid of losing my pear tree!
"Careful examination of infected plants reveals elongated, swollen galls on older wood. Needles may be shed from this swollen area and small or thin twigs may die if infected. Red to orange, jelly-like telia are extruded from the galls during wet weather in early spring."
If you have a juniper within 2 miles, you will probably just be re-infected each year. Cultural control consists of removing infected pear leaves before sporulation in the fall.
Unfortunately, there are no products labeled for home use of this problem. The best solution is to remove juniper trees in the area. When I told my neighbor of the problem and showed here the rust, she actually removed the tree. I do still get some of the rust , but I am very careful to remove the infected leaves, keep them raked off the ground and we still get a crop each year.
If removing local junipers is not an option, you might want to consider an alternate fruiting tree.
https://hortsense.cahnrs.wsu.edu/fact-sheet/pear-pear-trellis-rust/
I wish the news was better, as I too am afraid of losing my pear tree!
