All of our flowering plants seem to be getting black spots. It doesn't seem to matter the variety, sun exposure, moisture, etc. It's our peonies, tree peonies, lilacs, azaleas, and more. Some are in the front of our house, some along the side and some in the back. Some get more sunlight than others and some are on our sprinkler system (with water restriction it's only 15 minutes every other day) and some have no additional water. Does anyone know what's going on and how to fix it?

Probably aphid poop... looks like that may be the culprits on the stem there... blast em off with a spray from the hose and keep an eye to make sure they dont get out of control... I would not resort to any insectisides yet, just keep an eye on their population and keep spraying them off the plants as you see them.

Why not post a few more pictures including one of the soil and one of the whole plant, and tell us how you water and what kind of light the plant gets? I suggest you find out exactly what's wrong before doing anything else. Fortunately there are a lot of people here who have lots of experience raising all sorts of plants and dealing with just about any nasty thing that can harm them. I have a few guesses, but a little more information will help folks figure out what's going on and the best way to treat it. Fungus gnats live in the soil, so you have to do something to the soil to get rid of them. I treat them by periodically getting all of my plants to dry out at the same time, because they can't survive without wet soil. I've heard of people getting good results by dissolving part of a mosquito dunk in water and then watering lightly with it. I'm sure someone will pop in and give you some details. Often, the kind of wilting and yellowing leaves I see in your picture are signs of watering issues, and usually it's overwatering. Many people don't believe it's possible, but watering while the soil at the bottom of the pot is still wet keeps the rootlets that carry water to the plant from breathing and ends up killing them, making it look like the plant is thirsty when the problem is drowned roots. I can tell my plants are starting to get dry from their weight, but I check the soil moisture daily with a sharpened wooden dowel (just switched from a cheap moisture meter) stuck all the way to the bottom of the pot, and don't water until the first time the tip feels dry. At that point there's still moisture in the soil, but if I wait any longer the plant will wilt. At that point I water thoroughly until a lot of water has drained from the bottom of the pot and let the pot drain thoroughly. There are ways of helping this along, but we can get to that later. Best of luck!

I think its possible there was some dried residue left in the leaves then the sun hit it and it fried them. I would rinse the leaves really well w plain water and kinda rub with your fingers while rinsing. The new growth was more tender so probably fried quicker. You will probably have to wait for new growth to push through as it recovers. As it recovers, be careful with watering if you lose a ton of foilage..just water when barely dry because with less leaves, the rose needs less watering and you wont want to drown the roots. Let your rose tell you how much water it needs by checking the soil for dryness. Aphids can usually just be squished or squirted off with the hose. No need for insecticides :) Its easy if you have potted roses that arent too large yet because you can pick it up and tip it to get under the leaves with the hose or water faucet.