Well it certainly looks like yellow leaf spot disease.
I planted four of these Montmorency Cherry trees this spring, they were all doing great until summer started. They have all stopped growing, even though I am watering them regularly with fertilizer. I put a bucket of water on each every few days. They have been looking great, until the summer heat came in. I live in the Midwest, Illinois.
The last several days have been very close to the 100s, with brutal humidity. Suddenly, one of the cherry trees exploded with yellow spotted leaves. It had a few one day, which I pulled off. Too many to pull of the following day, and by day 3 its now about half of the tree covered in yellow spotted leaves. Its full scale, sick. Luckily, its the only cherry tree affected so far.
This guide to cherry trees is almost completely unhelpful in this case. It basically says yellowing, even spotted leaves could be overwatering, OR underwatering. OR, it could be leaf spot disease. OK
Given the fact that the tree appeared to be dying in front of my eyes, and having no guideance at hand I used every brain cell I had at my disposal, and decided it must be leaf spot disease.
So I then rushed out to the hardware store and got copper fungicide, which is professed online to be the ONLY thing that can stop leaf spot disease on tart cherries.
And so, following the directions, I sprayed the entire tree tonight, trying to get under the leaves also.
Was I right? You can see from the other pictures a nearby mulberry is affected by spots, although not as severe, as well as a Viburnum that was completely healthy yesterday and seems to have been hit by a Mack truck overnight as we say here.
I assumed it was the 100’F temperatures, and watered all three.
If they are all suffering from overwatering… heheh then that will be the death blow I’m sure.
Thanks for comments.
I am in Illinois. The last 3 weeks have been very bad for fungal infections. The combination of high humidity and quite a bit of rain hasn’t been good.
Looking at the pictures you supplied you may have cherry leaf spot. Picture two looks like cherry leaf spot. Picture three looks like something else. But it would take more pictures of the leaves with some of the leaves in earlier stages of infection to be more accurate in a diagnosis.
I would take a look at this thread dealing with cherry leaf spot and the links included in it.
Here is another thread you might find useful.
I usually spray my cherries with Daconil or Captan mixed with Immunox to control leaf spot. Which has worked in the past. Currently, I use Captan mixed with Indar.
I usually have a few leaves drop in high heat periods in the Summer. It’s a small portion of the leaves and not a problem. The leaves don’t have any spots on them when the heat alone is the cause of the dropping.
Our cherry season is over with so I have no worries about Pre Harvest Interval (PHI) - the minimum amount of time usally in days that must pass between the last application of a fungicide and when the crop can be harvested. PHI is a consern while fruit is hanging. And a bit of a guess when the fruit will ripen. I have to inform my wife when she can begin to sample the fruit.
Well here we are a month later, and temperatures are roasting and humid here, 95 today… its like standing in front of an oven just being outside.
Yeah. But anyway the yellowing leaves were definitely spreading alarmingly all over one of the trees… I ended up trying that Bonide or Captain Jack’s Copper Fungicide and it really did seem to work. That problem seems to be under control now.
However out of the four trees only one is growing at all. The other three are alive (as far as I can tell, lol) but have remained as stoic as plastic office plants, have not shown a centimeter in months.
Is this normal? It is their first year planted, but I would have expected at least something. They are getting plenty of sun and occasional buckets of water… I often mix in Miracle Gro fertilizer in with it but there are no miracles happening here thats for sure.
We also have had some massive rains, so its been something like the Amazon. But I still see what definitely looks like drought wilt with other plants in the backyard, and they come back after watering
