Looks like insect to me but not certain.

Firstyear:

The damage on your cherry leaves appears to me to be the initial symptoms of bacterial disease, which is often followed by bacterial canker of the twigs and branches. I don't think your problem is either insecticidal or fungal, but rather bacterial, which is the most difficult to arrest. Bacterial disease is common on cherry and other stone fruits, and is perhaps the most frequent reason for their eventual demise. You don't specify how old the tree is, nor whether it is a sweet or sour cherry. Please do if you post again. Also tell us if you can see any oozing cankers on your tree and whether the disease has affected any of your cherries.

The insecticide Sevin is of very little use on fruit trees, except against Japanese beetles. Sevin would have no impact on a bacterial disease, so you can put this chemical away for now.

The best defense I have found against bacterial disease is two dormant sprays with a strong copper solution such as the product called Kocide. Dormant copper can delay the onset of this disease, and slow it once it is underway. I wouldn't go so far as to say copper can cure this disease, but it will do better than anything else I have found. Copper sprays should be applied in late fall after leaf drop, and again in early spring just before bud break.

There is really nothing you can do about this disease for now during the growing season. Bacterial disease is a case for prevention, not cure, and the best prevention is dormant spraying.

Don Yellman, Great Falls, VA

jellyman, I brought the Sevin out as I saw a LOT of grubs this spring while digging and thought maybe they were starting to become active.

It's a sweet cherry. It was planted only 3 months ago, but it has been an unusually hot, humid June we're having...by New England standards at least. I planted two other cherries (one sweet and one tart) at the same time and neither are exhibiting similar damage. There doesn't seem to be any damage I can see on the shoots or trunk, just the leaves.

interesting...I think it may be insect. I went out this morning and noticed a leaf that was damaged overnight. It appears whatever is hitting it is eating the back of the leaves, but not touching the front. The leaf was fully green still and the partially eaten areas hadn't browned yet. There were 5 or 6 small oval black eggs deposited in a cluster near the damage. I inspected some of the other leaves that were damaged and there were eggs on some of those as well. I couldn't find eggs on any of the undamaged leaves.

Likely insect damage. Look up cherry slug.

Firstyear:

It would be comforting to believe that what you are seeing on your cherry tree is insect damage, but I don't think so. You won't really know how the disease will progress for at least a year, and in the meantime if you want to spray with Sevin or anything else have at it. I just don't think you will see any results.

Ask yourself this question: Why would insects single out one cherry tree among several to attack? Normally, when insects damage the leaves on a tree, all trees of the same type suffer similar damage. Disease, on the on the other hand, can be present on one tree and not on other, nearby trees. At least not yet.

If your tree is diseased, it is only a matter of time until the others suffer the same fate. Sweet cherries are one of the most difficult things you can choose to grow in the East, but thorough dormant spraying with copper at least might give you a shot for a few years.

Don Yellman, Great Falls, VA

Don, sweet cherries are not difficult to grow up here and I've yet to lose a single tree to bacterial leaf spot. When I see symptoms like those in the photo but most of the leaves are healthy with good growth I ignore them. The only issue common to the trees I manage is canker which only tends to occur in my nursery in shady spots.

Here it is not unusual to see 100 year old monster cherry trees that have not been tended to for decades.

First year, if you are really curious what is causing your problem, I would not rely on photo diagnosis here, as wise and experienced as some participants here may be (I'm describing Don). The horticulturist at your cooperative extension can look at the injury under microscope and give you more accurate diagnosis for five bucks and for thirty have a pathologist do the same.

Cherry trees usually thrive here, what's more difficult is getting the crop because of birds and their tendency to crack in humid conditions.

Thanks guys. I'm more curious than concerned by the leaves at this point. I figure if I put pictures up at least I'll have an idea on how to treat or what to look for going forward. The tree is putting out strong growth and doing well otherwise, so I guess I'll just have to wait and see until next year how it's doing.