Hello Jason, around here sweetgums get to be really good sized trees. It is odd one has the black curl and I can see the veins in its foliage but not the other. Not sure what is bothering yours but is there really room for two of them there anyway?

I dont know why the leaves are black at the edges but there is a house down the street from me that has 4 sweet gum trees that are planted only feet apart.

here is a pic

It has 'severe' chlorosis which I've never saw on a sweetgum.

Dax

Thank you, all.
Dax, sever chlorosis appears to be very likely... I'll see what I can do.

Thanks again.

How does it have it soo bad on one and not the other? Chlorosis is a soil problem or am I thinking of it backwards?

Yes, foliar chlorosis is almost always associated with one or more mineral nutrient deficiencies, often to iron and/or manganese. Sometimes nitrogen itself. The black leaf edges are a separate issue, most likely a bacterial or fungal leaf scorch syndrome. So, two different things going on with those leaves.

OP, while your soil may be low in iron and/or manganese, it is at least just as likely that the actual genesis of the problem (of the chlorotic foliage) is a too-high soil pH. You can have that checked. So, if in fact, the soil pH is too high for the species, soil sulfur can be applied rather liberally around the root zone of the tree. In time, that will drive down the pH and the tree will be able to better access the nutrients it needs. However-and this is especially true in fine-textured soils (clay-based), in time, the pH will tend to drift right back to where it was via soil buffering capacity. Just something to be aware of-you can easily reapply the acidifying agent.

+oM

Sweetgums prefer an acid to neutral soil - not sure what the pH is there, but I've seen them around Dayton, OH looking just fine, with soil pH in the mid 7's. I can't imagine yours is any higher than that in SF, but I could be wrong.