I think too much rain did it.

Your roses look fine.

The lower yellow leaves is the signature. Your roses will have to ride through a rough patch of time. We in the northeast got too much snow and Texas got too much flooding rains. Too bad we couldn't sell it in train cars to California.

I have learned that now there is diseases causing organisms in the soil. (Anerobic). It happened one year when I was in the path of one of those hurricanes you are so familiar with. Now you need oxygen in the soil. Light rain puts oxygen into the soil.

Try some Compost tea aerated to put good biology (aerobic) in.

I would rake away that grass which is kind of suffocate and use 2 inches of good light fluffy finished yard waste Compost and pine straw mulch or shredded leaves. Clear out a little area where you dont step in like a flower bed. Kind of like a flooded basement in a house. It has to be cleaned up a little. Pick the leaves with the black and get them away.

When I was a beginning rose grower, I planted everything too close. Roses need air. The fence is too close. But don't move the rose in the hot season.

That rose glo looks like a great rose food.

It will be a tough year for your Rose but they'll make it through it we all do. :)

That doesn't look like over fertilization to me at all. I agree with Sam it looks more weather related than anything.

The yellowing is from black spot disease.

With excess rain it's OK to fertilize a bit more than usual, because available nitrogen can wash out of the soil. The typical symptom of over fertilizing is burning around the edges of leaflets.

I agree with Michael, it looks like black spot to me. Lots of rain will do that. Spray it with fungicide and it let it grow, it will be fine. If it was because of lack of draining it would affect all the leaves, not just the bottom ones. Fertilizer burn looks different. It looks like the leaves getting crispy from the sun. This is not that.

Its gotta be too hot in San Antonio for a new BS infection to start now. I'm with Nipstress, just pick off the yellow leaves & don't spray. Its tricky to spray in hot weather without damaging the foliage.