second pic is lichens.. irrelevant ..

the leaves look like cold damage ...

and i dont know on the rest

ken

Pretty classic anthracnose symptoms if you ask me - bark/trunk cankers and leaf tip necrosis and spotting. Trees can linger on indefinitely with this ailment but I'd plan on removal/replacement somewhere down the road.

I don't have much experience with dogwood anthracenose, but that it's in full sun, and I assume good air circulation would tend to prevent anthracenose of dogwoods. The leaf discoloration is probable due to insufficient sap making it to the leaf tips. IME, cold does not damage dogwood leaves very often. All that put together, I lean toward canker. IIRC, there are several of C. florida. IMHO, take the tree out. If you want another one, then wait at least one year before replanting. Also if you do take the tree out, get the roots out as well, so that you can examine them for possible problems as well.

Arktrees

I agree with Gardengal.

'Appalachian Spring' might be considered if another Cornus florida is preferred as a replacement.

Thanks for the insight. This one is not threatening the house so it can live or die naturally. To me anthracnose meanse keep the leaf debris away from it in the fall. Really it does not have the best air circulation. You would think back in the day when the ash was over it would have been typical anthracnose time.

Perhaps stress from suddenly being in the sun weakened it.

If I can live with a declining tree in that spot, is there another reason to remove it, like keeping any disease from spreading?

Unless you have more dogwoods in the near vicinity, I wouldn't worry about spreading the disease. The disease is fairly ubiquitous in most areas where dogwoods are found.

Stressed trees are more likely to be affected. Like with most plant disease, weaker trees are much more likely to be affected, and, once infected, the diseased trees are much more prone to other diseases/issues.