In Mississippi, it is probably best to cut roses back by a third after the first year. In subsequent years, cut out weak, twiggy growth and dead or diseased wood. As the bushes age, cut out some of the older wood to its base to make way for new growth. Branches can be cut back by a third to a half, if needed, but I prefer light or selective pruning. Roses need five to six hours of direct sun each day.
Morning sun is essential, but afternoon shade is tolerated.
Good air movement helps the dew and rain dry quickly, discouraging disease. Plant on raised beds with plenty of organic matter incorporated. Avoid planting under eaves or gutters where bushes can be damaged by falling water. Plant your roses where they are easy for you to watch and enjoy. This will also keep you tuned to any insect or disease problems.