Propagate Rose Cutting Using a Potato. Cut an 8-inch piece of healthy rose bush with clean clippers. Snip off flower head or hip and leaves. Take a medium sized potato and drill a 3" hole in it using a clean screw driver (same diameter as cutting). Dip rose cutting's end in rooting compound and place cutting in potato. Plant potato in pot filled with moist potting soil. Place pot in warm area, indirect light. Keep moist.