Knowledgebase
Serviceberry & Juniper Rust? #874398
Asked June 24, 2024, 10:49 AM EDT
Washington County Minnesota
Expert Response
How to manage cedar serviceberry rust.
https://extension.umn.edu/plant-diseases/cedar-apple-rust
Please check out a previous reply to a similar question, that of what to do about the rust. Pruning it out isn’t an option this year.
Unfortunately, juniper is an alternate host.
Rust on Serviceberry #459813
Asked June 05, 2018, 1:36 PM EDT
My serviceberries are inedible this year as there is a orange hairy-like fungus on the fruit. The leaves look okay so far. Should I treat with anything? Will it go away next season? I think I read that it is rust from an evergreen. I have two evergreens: a holly and a laurel; both are ok-- sometimes I cut dead parts out of them. Could it have come from them? Several feet away, I just had 15 yo tulip popular die. The last few years it was struggling- a couple of limbs were dead and leaves had black spots on them. It is totally dead now. On the other hand, neighboring maple tree has had black spots on leaves for several years and so far, the leaves all look pretty healthy.Jefferson County Kentucky
Expert Response
As serviceberry is in the rose family (Rosaceae), it is susceptible to many of the same disease and insect pest problems seen in other species within the family (e.g. apples and pears). This includes rust diseases. Cedar-serviceberry rust affects twigs, buds, fruit and foliage and can disfigure these plant parts or result in witches’ brooms.
Wet spring weather and stresses in the environment have made many serviceberrys susceptible to rust this year. The rust disease does require two hosts, a juniper (eastern red cedar is actually a juniper) which is not damaged by the rust, and a serviceberry, (apple, hawthorn, etc.) where we see affected growth. The holly and laurel do not host this disease. Maples and tulip poplars do not share rust disease.
About rust disease: https://plantpathology.ca.uky.edu/files/ppfs-fr-t-05.pdf
Nothing can be done this year except good sanitation to minimize the rust spores in the area. Spray next year to control with an appropriate fungicide. Fungicides protect uninfected plant material, they do not cure the plant of disease. Multiple applications of fungicide are necessary for good control.
Next year’s leaves and fruit will start out uninflected.
Follow the disease management advice to reduce infection. Also, if next year is not rainy, there maybe less disease.
If you were living in the city I would say that there are junipers nearby in other yards so removing the junipers won’t do any good. If there are no junipers for 2 miles you may consider removing yours. The decision to take out the junipers depends a little on how much the rust bothers you. The disease usually doesn’t do lasting harm to service berries. Because nothing needs to be done this year you don’t have to rush to decide what to do about the junipers. Waiting to see how bad it is usually won’t affect tree health.
https://yardandgarden.extension.iastate.edu/encyclopedia/cedar-apple-rust
Ok thank you so much, I appreciate it!
