Learn when it's safe to transplant seedlings. The first two leaves visible are usually "cotyledons," or seed leaves. Once the seedling grows several "true leaves," with a more typical rose leaf appearance, it is more likely to survive transplanting. It is also easier on plants if they are transplanted to a larger pot for a year or two, and then transplanted outside.
Remove the seeds from the fridge. Try to do this around the time that the seeds would normally start to germinate, such as in early spring. Make sure that the environment outside of the fridge is about 70 degrees Fahrenheit. The seed will not sprout until you take them out of the fridge. Depending on the rose variety and individual seeds, the seeds could take anywhere from four to sixteen weeks to germinate. Often, 70% or more of the seeds never sprout at all.
Rose seeds need to go through stratification (an artificial cold spell) for 10 to 12 weeks before they will sprout. This, combined with a germination success rate of 20-30% makes propagation by seed an unattractive prospect. on by seed an unattractive prospect. If you still want to try it, find a good source of information that will guide you through the process.