Well nobody has responded I suspect because nobody knows. The Vinca looks perfectly happy so it doesn't appear to be a cultural problem e.g excess water or lack of nutrients It could be be fungal in which case you could cut out all the brown and hope for the best. Cut the brown twigs back into healthy tissue. Don't just remove the brown leaves. If you don't mind using chemicals you could try a fungicide. But that is only a guess. I've never seen Sarcococca with any problems. But I found a reference to Cylindrocladium buxicola aka box blight which says it affects both box and Sarcocca and I believe it has reached N America. Google it up and see what you think. Here is a link that might be useful: Box blight

Aunt Lou, here's a clip from the link I left above: "Severe powdery mildew infection will result in yellowed leaves, dried and brown leaves, and disfigured shoots and flowers. Although it usually is not a fatal disease, powdery mildew may hasten plant defoliation and fall dormancy, and the infected plant may become extremely unsightly." My mums look horrible right now. It bloomed early, and looked fine. When I got back from vacation in early Aug. I could see it had pm. I cut many of the stems back because the buds were affected too. Here's a description of aster yellows: "The first symptom of the disease is vein clearing, the loss of chlorophyll or green pigment in the leaf veins. This is followed by yellowing of newly formed leaves, sporadic bushy growth, erect growing habit, and stunting. Stems and flower stalks may be numerous and spindly. Flowers often remain green and become distorted. Seeds and fruit do not develop. Specific symptoms vary with the kind of plant. The leaves of infected carrots grow in tight bunches. The inner leaves are yellow and stunted, while outer leaves turn rusty red to reddish purple. The roots are bitter, stunted and deformed, with tiny hair-like roots growing all over the main root. Infected glads may have thin, weak, yellow leaves, and the flower spikes may be twisted and deformed, while the flowers remain green. The whole plant is generally stunted and spindly, and the top is often killed. Asters have stiff yellow growth with many secondary shoots and are stunted. In warm weather, symptoms are more severe, and appear more quickly. At 55 degrees or less, plants may be infected without the symptoms being obvious. " Some years can be really bad for fungal problems, the weather and plant stress are 2 things that can make it worse. Like Loretta mentioned above, aster yellows deforms the whole plant, including the flowers. Kat

Don't do anything. That is most likely winterburn. There is a lot of it with many of our broadleaf evergreens, especially rhododendrons, after the long bitter cold of this winter. The dead leaves will naturally drop off, tho perhaps not as fast we we would like. I give my evergreens some extra TLC with fertilizer (which I don't usually give them) and being careful to water if needed. They will come back as good as new tho it can take a few months, depending on how bad the damage is.

The color also looks too yellow to be right. From the photo, it looks like it may have been planted too deep since I cannot see the root flare, the part of the trunk where the base of a tree broadens slightly, though it might be just hidden by mulch. Or it may have come from the supplier planted too deep. IME pin oaks are reasonably happy with OH soil. Mulch shouldn’t be against the trunk, so pull that back. Ideally mulch will start a few inches from the trunk and go out to the drip line of the tree on a small tree such as this to reduce competition from grass. I would pull aside the mulch and soil until you find the root flare to see how deeply it is planted compared to the flare. Have you done a pH test? What has the weather, particularly rain, been like this year compared to usual?