Summarize this article:

Roses require about 1" of rain each week, so make sure that you supplement their water needs if the rain isn't falling. Water them at the base of the plant near the soil. While you can't control where the rainfall lands, if you add water to your plants make sure that you're avoiding buds and leaves. Otherwise, your plant may suffer diseases and rot, which can result from water. Instead, focus your watering on the roots. To make sure that your soil is moist but not soggy, check it 2-3 times a week. If it feels dry, add water. Allowing the roots to get too wet can harm your plant, so if your soil has been soggy, give it time to dry before adding more water. Place a 2-4-inch (5-10 cm) layer of mulch around your rose plants. The mulch will help keep your plants moist, and as a bonus it will also help protect against weed growth. During the winter, mulch can also help keep your roses from freezing.

Summary:
Make sure that the roses get enough water. Avoid watering the leaves and blooms. Check the soil 2-3 times a week. Add mulch to your soil.