Might be Botrytis Blight or thrips - I am having the same problem with 2 of my English roses (Even the buds turn brown on the edges as they are opening), and I don't know what to do about it. Hopefully someone else here can help.

Yes, if it is thrips you can see very tiny elongated insects scurrying when you look between the petals, and the petals have a scratched-up look. They like to feed on the tips of the petals when a bud is just starting to open, resulting in the brown edges. With Botrytis you get rotten brown spots and (on some varieties) pink spots. Roses can also get sunburn if it is hot with low humidity.

So, what would one do about such critters?

I don't do anything about thrips. In my garden, they are usually not bad except during part of the first flush of bloom. Some people spray buds (not open flowers, please) lightly with insecticide.

There's not really much you can do about it, but some roses are more susceptible than others. For instance, Lagerfeld is very delicate and gets the brown edges a lot, but Black Magic never has any brown edges. It has to do with the color and thickness of the petals.