Cherry shot hole prevention

Question: From the MD Extension Service website, it appears my Yoshino Cherry Tree has cherry shot hole disease, which is described as perpetual fungus hard to kill. My questions follow: How does this fungus winter over here in Maryland. Does it all die, and the leaves are reinfected with spores in the air from elsewhere? If it is important to gather the leaves up, it seems that the following spring's new leaves will get the fungus from spores from the prior year.If the fungus re-infects locally from prior years, is there a benefit to spraying the bark and limbs and the surrounding ground with a fungicide routine in the fall/winter/spring, etc?  If so, what fungicide would be effective, since I cannot afford an arborist.Can you tell which fungus it is from the photo attached? Currently, the tree has lost 80% of leaves (mid August), started dropping in mid July so we watered it thinking it was suffering from drought which was probably the last thing I should have done due to keeping it wet. Remaining leaves look like swiss cheese. See picture. Thank you so much for helping me out with this!!!!! Jenny

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied August 26, 2024, 11:10 AM EDT
response: We agree that the symptoms pictured appear to be caused by Cherry Shot Hole, a very common disease among flowering cherries. The infectious agent could be a fungus or a bacteria...in cherry trees, it's often the fungus, though symptoms alone are not enough to diagnose which pathogen is responsible, since they will essentially look alike.  Spores overwinter in infected plant debris, so while raking away and disposing of fallen leaves from an infected cherry is helpful to reduce the likelihood of severe infection the next year, it's not a foolproof way to completely prevent recurring infection, as spores might be blown in from miles away. (This is how a tree that didn't have the disease before tends to become infected in the first place.)  The pathogen isn't hard to kill per se, as certain fungicides can work well, it's just that it's usually more expense and effort than it's worth, because the disease doesn't tend to impact trees too severely (beyond aesthetic damage). Granted, multiple years in a row of heavy infection might weaken a tree, especially if it has to contend with other conditions simultaneously (like drought or a root zone that stays too wet), but we've seen trees contend with this infection for many years and still grow and flower normally each spring.  The ground would not be sprayed with fungicide; the new leaves of the tree each spring would get the protective spray, and it would have to be re-applied several times well into the spring and early summer in order to suppress infection. Rain or other weather conditions could interrupt a spray schedule, allowing infection to take place. Plus, fungicides might risk harm to pollinators or other organisms. Both of these are reasons why we seldom recommend fungicide treatment to manage diseases like Shot Hole. Spraying usually needs to be done by a certified arborist or certified pesticide applicator (arborists often have this certification), since the entire canopy needs even, thorough coverage by the spray, and they will have better-calibrated equipment than the general public usually purchases. They will also have protective equipment (PPE) to guard against exposure to drips from the canopy.  It is much more important to alleviate drought stress by watering roots than to avoid watering out of concern for spreading disease, especially once that disease has already manifested symptoms. Trees can recover from seasonal leaf infections much more easily if the roots are in good health than if roots are stressed or dying back due to drought.  Miri

responder: The Question Asker Replied August 26, 2024, 10:20 PM EDT
response: Thanks so much, it all makes perfect sense.:) On Mon, Aug 26, 2024 at 11:10 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied August 27, 2024, 9:25 AM EDT
response: You're welcome.