Sounds much more like insect damage, a photo would help confirm. Unlikely to be worth spraying.

No harm in mulching, that certainly won't cause the holes in the leaves.

Resin

I agree with the first poster that is holes in the leaves are cause by insects

Dear Pineresin and tmore,

Thanks for your thoughts. I'm pretty sure it is not insects...but as I can't post a picture right now it's hard to give you more to work with.

If anyone else has had holes that were anything but insects I would like to hear how it worked out.

Thanks,
Lex

The holes in the ornamental cherry/plum are likely shot hole fungus, a very common issue with prunus species in our damp climate. It is only cosmetic and is not significant enough of a problem to treat. And it has nothing to do with the type of mulch you use, although the fungal spores carried on fallen leaves can persist over winter if you don't rake and clean up properly. Mulching is very good for the trees for any number of reasons as long as you don't overdo nor pile it up next to the trunk. Wood chip mulch is considered one of the better mulches for this purpose and the presence of mushrooms or other fungal bodies in the mulch is just a sign that it is doing what it should be, beginning to decompose. The majority of fungi associated with decomposition are beneficial to plants in the long run and not disease carrying or pathogenic organisms.

I'm not sure what's up with the maple, as these do not tend to get a similar shot hole problem. It could be tar spot or just as easily, small insect damage. Difficult to confirm without photos. And you may want to keep a closer eye on the prunus species - they are prone to a huge number of disease and insect problems, especially in a PNW climate - shot hole is really not a serious issue but various bacterial blights, fire blight, black knot and gummosus are.

Yes, likely shothole.

But the fungus on the chippings on the ground isn't related to any sort of plant disease. That white stuff is part of the composting process as the chips and all break down.

To clarify a bit on the other diseases suggested just above
-- bacterial blight is extremely common west of the Cascades. You'll need to apply dormant sprays every year.
-- fireblight is common east of the Cascade, but uncommon to rare west of the Cascades. Best remedy is to plant resistant varieties.
-- black knot is rare in Oregon. To date, the only cases (2) I've seen (heard about) were on young mail-order trees from east of the Mississippi.

Thank you GardenGal and Jean,

I put the trees in and then didn't ever learn about spraying. I will do my homework on that and do dormant sprays. I'm glad to hear the shot-hole fungus is no big deal.

I will look at my plum to see if any other issues are evident. It's growing like crazy in spite of the shot hole in any case.

I'm relieved to hear that my mulching is not a bad thing. I have been putting INCHES on everywhere in the yard for the last several years and it's made such a difference with weeds -- I had put it too close to the tree trunks and have remedied that this year.

While I have your 'ears': I have been having some bacterial canker on my cherries (2 and 3 year old trees) identified from the books I have. Light and amber sap oozing and creating little, fingernail sized, bulges in some places on branches, just oozing from some other nodes. We lost an apricot this spring (to borers, it seems, there was little sawdust coming from many nodes). From what I've read the oozing on cherries is not related. Any advice on that?

Thanks!
Lex

Cherries and other stone fruits are very susceptible to bacterial canker. You can slow down the disease, but not stop it, with annual dormant sprays. It's the reason I'll be removing my peach tree this year.

Jean,

I'll keep an eye on the plum. Do you think I should remove the cherries? They are 2 and 3 years old, planted close to each other and the plum I described is about 25' away from that. I'd hate to loose any of them but hate more to loose them all.

thanks,
Lex