Like all living plants, roses may be attacked by insects and fungus diseases. It is important to apply one application of dormant spray to each rose. A good copper fungicide, combined with a spray oil may be used to control both over-wintering insects and diseases in a single spraying.
Mulching is very important. It keeps the soil cool in summer and warm in winter. It retains moisture, controls weak growth, and renews and rebuilds the humus content of the soil around the plants.
Roses are heavy feeders and need food to get the maximum bloom, but not in the winter dormant season. The rule of thumb is to give them their first feeding in March or when the rose has six inches of new growth (whichever happens first). After that, every two months through October is recommended.
Roses can take lots of water during the growing season if the drainage is good, but will not tolerate wet feet in the winter. You should not have to water your plants until there is at least 6″ inches of new growth and the soil starts to dry out. Avoid watering at night to cut down on fungus and disease.
On newly planted bushes, cut off the flowers on the shortest stems, to allow more nutrients to go into the remaining flowers. On established plants, you can cut as high as the second (five-leaf) leaflet or as low as any two leaflets above the previous cut in order to promote more blooms – leaving as much foliage as possible.