I have 3 knock-out roses that are about 4 years old. Each year they
have been great except this year. The leaves have developed white spots
which seem to be turning into voids. I looked closely for bugs, mold,
or something (on both sides of leaves). But I can not see anything
alarming. Does anyone have an idea? BTW, I have 3 different knock-outs
in front of the house doing great!