Do you have those black spots on the leaves of your rose bushes, followed by yellow leaves and then bony stems and no leaves?  Yep, you have black spot fungus on your rose bushes.  Unfortunately the leaves which are showing black spots cannot be salvaged, but you can stop the spreading of the fungus to the rest of the plant and it will comeback full and beautiful with these easy kitchen mixes.  You can mix 1/2 a cup of baking soda and a gallon of water together in your watering can and rinse over the rose bushes on a sunny day and it will kill the fungus and the plant can grow back to it's normal beauty.  Pull off those leaves with black spot on them.  Or you can mix 1/4 cup of skim milk in a gallon of water in your watering can and rinse over the rose bushes too.  It will last longer and not leave a chalky white residue like baking soda does, plus the rose bush will sprout many new growth stalks since it responds to milk just like a good fertilizer.  The milk is the best, but both will work.  I would repeat this rinse every 4 weeks.