Insert the spade into the soil 18 inches away from the Rosa rugosa and dig a trench completely around the shrub, cutting through the roots as you dig. Completely sever the roots with each insertion of the spade into the soil.
Fill the trench with soil after root pruning and water to a depth of 10 inches. Wait until fall to transplant the Rosa rugosa.
Water the Rosa rugosa every day the week before you transplant. Soak the soil until water puddles at the base of the shrub.
Prepare the new location by digging a hole at least 20 inches in diameter and 18 inches deep. Add amendments, such as shredded bark or coarse sand, to aid drainage.
Lay a tarp or place a wheelbarrow next to the Rosa rugosa. Dig up the rose, keeping as many roots as possible. Start digging 18 inches away from the shrub. Shake the soil from the roots, gently.
Place the shrub in the wheelbarrow and wheel it to its new location. Or, if you are using the tarp, lay the shrub on the tarp and drag it to the new location.
Place the Rosa rugosa in the new planting hole. Add or remove soil so that the shrub sits at the same depth as it did in the old location. Fill the hole with soil, patting it as you fill to remove air pockets.
Water deeply -- to at least 8 inches -- and keep the soil moist while the Rosa rugosa becomes established in its new location. This generally occurs within three weeks.