I got some Rosa rugosa seeds from a friend and had great success with them. I believe they were fresh. I just filled some 1/2 gallon pots with a soiless mix, planted the seeds about a half inch deep and kept them moist. Now would be a good time to do it as the warm temps will get them going. Because these are such hardy roses, and I'm in zone 5 I didn't have to worry about winter protection. I do have some 20 bushes now tho, and will have to find them homes. One concern I have is that the birds will have equally as good success with the seeds and l will have rose bushes sprouting up all over the place. You may want to identify the roses before you grow a bunch of them.