A simple potato is a great way to propagate roses. Potatoes contain just the right amount of nutrients and moisture for rose cuttings to develop and grow healthy roots. Note: this method also works for many other wood-stemmed plants.
The SECRET to propagating roses is said to be the "potato"! TIP: Before planting rose cuttings, push the bottom end into a small potato, which keeps the cuttings moist as they develop roots. It sounds crazy, but apparently it works really well.
Grow roses from a cutting. Simply cut healthy stems, place them in large potatoes, and then bury them inches deep in a healthy soil mixture of peet moss and top soil. The potatoes keep the stems moist and help develop the root systems.