Red-brown or plain brown spots sound like leaf spot. Very common when the weather gets humid but goes away when the dry summer weather arrives. I would throw away the dead leaves in the trash, clean up plant debris that may harbor spores, replace the mulch with new mulch and make sure there is good ventilation around the plant.

With all the rain, you need to also be careful of the possibility of root rot. Make sure the soil is not wet wet or that it remains wet because that can cause root rot; luckily for you, PJM is highly resistant Phytophthora crown rot.

Since we are in the summer months, flower buds production has probably started so now is the time to maintain the soil moist and not fertilize until next Spring. Fertilizer added now will just stress the plant some more, make it grow tender leaves that will not survive the winter months and can even cause a problem called bark split.

Let us know if you notice any other new symptoms.

Luis