Plant the rose bush seeds approximately ¼ inch deep in a seed-planting mix in seedling trays or your own planting trays. The trays need not be more than 3 to 4 inches deep for this use.
When planting rose seeds from various rose bush hips, I use a separate tray for each different group of seeds and label the trays with that rose bushes name and planting date. The planting mix should be very moist but not soaking wet. Seal each tray or container in a plastic bag and place them in the refrigerator for 10 to 12 weeks.
Planting Roses from Seeds The next step how to grow roses from seed is to sprout the rose seeds. After having gone through their “stratification” time, take the containers out of the refrigerator and into a warm environment of around 70 F. (21 C.). I do my best to time this for early spring when the seedlings would normally be coming out of their cold cycle (stratification) outside and starting to sprout.
Once in the proper warm environment, the rose bush seeds should start to sprout. The rose bush seeds will usually continue to sprout over the course of two to three weeks, but probably only 20 to 30 percent of the rose seeds planted will actually sprout.