A few hardy shrub roses are grafted. Grafts should be about an inch below ground level. Ideally, the soil should always be damp. Mulching 3-4 inches deep with an organic mulch will help maintain the moisture. When you water between rains, be sure to apply the water at the base of the plants.
Wet foliage is more prone to diseases.
They should be fed monthly from April through August, following the directions on the fertilizer package. Roses also like rotted manure and compost. Mulching is very important with roses, for moisture retention and to help keep out weeds. Bark mulches or cocoa bean hulls are great, but avoid rock mulch which compacts the soil and gathers heat. You don't have to, but you may want to.